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Display How Many Bucketed Items Live Within a Sitecore Item Bucket Using a Custom DataView

Over the past few weeks — if you haven’t noticed — I’ve been having a blast experimenting with Sitecore Item Buckets. It seems new ideas on what to build for it keep flooding my thoughts everyday. πŸ˜€

However, the other day an old idea that I wanted to solve a while back bubbled its way up into the forefront of my consciousness: displaying the count of Bucketed Items which live within each Item Bucket in the Content Tree.

I’m sure someone has built something to do this before though I didn’t really do any research on it as I was up for the challenge.

darth-vader-didnt-read

In all honesty, I enjoy spending my nights after work and on weekends building things in Sitecore — even if someone has built something like it before — as it’s a great way to not only discover new treasures hidden within the Sitecore assemblies, but also improve my programming skills — the saying “you lose it if you don’t use it” applies here.

nerds

You might be asking “Mike, we don’t store that many Sitecore Items in our Item Buckets; I can just go count them all by hand”.

Well, if that’s the case for you then you might want to reconsider why you are using the Item Buckets feature.

However, in theory, thousands if not millions of Items can live within an Item Bucket in Sitecore. If counting by hand is your thing — or even writing some sort of “script” (I’m not referring to PowerShell scripts that you would write using Sitecore PowerShell Extensions (SPE) — I definitely recommend harnessing all of the power this module has to offer — but instead to standalone ASP.NET Web Forms which some people erroneously call “scripts”) to generate some kind of report, then by all means go for it.

counting

That’s just not how I roll.

aint-no-time-for-that

So how are we going to display these counts to the user? We are ultimately going to create a custom Sitecore DataView.

If you aren’t familiar with DataViews in Sitecore, they basically allow you to change how Items are displayed in the Sitecore Content Tree.

I’m not going to go too much into details of how these work. I recommend having a read of the following posts by two fellow Sitecore MVPs for more information and to see other examples:

I do want to warn you: there is a lot of code in this post.

arghhhhh

You might want to go get a snack for this as it might take a while to get through all the code that I am showing here. Don’t worry, I’ll wait for you to get back.

eat-popcorn

Anyways, let’s jump right into it.

partay-meow

For this feature, I want to add a checkbox toggle in the Sitecore Ribbon to give users the ability turn this feature on and off.

bucketed-items-count-view-ribbon

In order to save the state of this checkbox, I defined the following interface:

namespace Sitecore.Sandbox.Web.UI.HtmlControls.Registries
{
    public interface IRegistry
    {
        bool GetBool(string key);

        bool GetBool(string key, bool defaultvalue);

        int GetInt(string key);

        int GetInt(string key, int defaultvalue);

        string GetString(string key);

        string GetString(string key, string defaultvalue);

        string GetValue(string key);

        void SetBool(string key, bool val);

        void SetInt(string key, int val);

        void SetString(string key, string value);

        void SetValue(string key, string value);
    }
}

Classes of the above interface will keep track of settings which need to be stored somewhere.

The following class implements the interface above:

namespace Sitecore.Sandbox.Web.UI.HtmlControls.Registries
{
    public class Registry : IRegistry
    {
        public virtual bool GetBool(string key)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetBool(key);
        }

        public virtual bool GetBool(string key, bool defaultvalue)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetBool(key, defaultvalue);
        }

        public virtual int GetInt(string key)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetInt(key);
        }

        public virtual int GetInt(string key, int defaultvalue)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetInt(key, defaultvalue);
        }

        public virtual string GetString(string key)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetString(key);
        }

        public virtual string GetString(string key, string defaultvalue)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetString(key, defaultvalue);
        }

        public virtual string GetValue(string key)
        {
            return Sitecore.Web.UI.HtmlControls.Registry.GetValue(key);
        }

        public virtual void SetBool(string key, bool val)
        {
            Sitecore.Web.UI.HtmlControls.Registry.SetBool(key, val);
        }

        public virtual void SetInt(string key, int val)
        {
            Sitecore.Web.UI.HtmlControls.Registry.SetInt(key, val);
        }

        public virtual void SetString(string key, string value)
        {
            Sitecore.Web.UI.HtmlControls.Registry.SetString(key, value);
        }

        public virtual void SetValue(string key, string value)
        {
            Sitecore.Web.UI.HtmlControls.Registry.SetValue(key, value);
        }
    }
}

I’m basically wrapping calls to methods on the static Sitecore.Web.UI.HtmlControls.Registry class which is used for saving state on the checkboxes in the Sitecore ribbon — it might be used for keeping track of other things in the Sitecore Content Editor though that is beyond the scope of this post. Nothing magical going on here.

I then defined the following interface for keeping track of Content Editor settings for things related to Item Buckets:

namespace Sitecore.Sandbox.Buckets.Settings
{
    public interface IBucketsContentEditorSettings
    {
        bool ShowBucketedItemsCount { get; set; }

        bool AreItemBucketsEnabled { get; }
    }
}

The ShowBucketedItemsCount boolean property lets the caller know if we are to show the Bucketed Items count, and the AreItemBucketsEnabled boolean property lets the caller know if the Item Buckets feature is enabled in Sitecore.

The following class implements the interface above:

using Sitecore.Diagnostics;

using Sitecore.Sandbox.Determiners.Features;
using Sitecore.Sandbox.Web.UI.HtmlControls.Registries;

namespace Sitecore.Sandbox.Buckets.Settings
{
    public class BucketsContentEditorSettings : IBucketsContentEditorSettings
    {
        protected IFeatureDeterminer ItemBucketsFeatureDeterminer { get; set; }
        
        protected IRegistry Registry { get; set; }

        protected string ShowBucketedItemsCountRegistryKey { get; set; }

        public bool ShowBucketedItemsCount
        {
            get
            {
                return ShouldShowBucketedItemsCount();
            }
            set
            {
                ToggleShowBucketedItemsCount(value);
            }
        }

        public bool AreItemBucketsEnabled
        {
            get
            {
                return GetAreItemBucketsEnabled();
            }
        }

        protected virtual bool ShouldShowBucketedItemsCount()
        {
            if (!AreItemBucketsEnabled)
            {
                return false;
            }

            EnsureRegistryDependencies();
            return Registry.GetBool(ShowBucketedItemsCountRegistryKey, false);
        }

        protected virtual void ToggleShowBucketedItemsCount(bool turnOn)
        {
            
            if (!AreItemBucketsEnabled)
            {
                return;
            }

            EnsureRegistryDependencies();
            Registry.SetBool(ShowBucketedItemsCountRegistryKey, turnOn);
        }

        protected virtual void EnsureRegistryDependencies()
        {
            Assert.IsNotNull(Registry, "Registry must be defined in configuration!");
            Assert.IsNotNullOrEmpty(ShowBucketedItemsCountRegistryKey, "ShowBucketedItemsCountRegistryKey must be defined in configuration!");
        }

        protected virtual bool GetAreItemBucketsEnabled()
        {
            Assert.IsNotNull(ItemBucketsFeatureDeterminer, "ItemBucketsFeatureDeterminer must be defined in configuration!");
            return ItemBucketsFeatureDeterminer.IsEnabled();
        }
    }
}

I’m injecting an IFeatureDeterminer instance into the instance of the class above via the Sitecore Configuration Factory — have a look at the patch configuration file further down in this post — specifically the ItemBucketsFeatureDeterminer which is defined in a previous blog post. The IFeatureDeterminer instance determines whether the Item Buckets feature is turned on/off (I’m not going to repost that code here so if you haven’t seen this code, please go have a look now so you have an understanding of what it’s doing).

Its instance is used in the GetAreItemBucketsEnabled() method which just delegates to its IsEnabled() method and returns the value from that call. The GetAreItemBucketsEnabled() method is used in the get accessor of the AreItemBucketsEnabled property.

I’m also injecting an IRegistry instance into the instance of the class above — this is also defined in the patch configuration file further down — which is used for storing/retrieving the value of the ShowBucketedItemsCount property.

It is leveraged in the ShouldShowBucketedItemsCount() and ToggleShowBucketedItemsCount() methods where a boolean value is saved or retrieved, respectively, in the Sitecore Registry under a certain key — this key is also injected into the ShowBucketedItemsCountRegistryKey property via the Sitecore Configuration Factory.

So, we now have a way to keep track of whether we should display the Bucketed Items count. We just need a way to let the user turn this on/off. To do that, I need to create a custom Sitecore.Shell.Framework.Commands.Command.

Since Sitecore Commands are instantiated by the CreateObject() method on the MainUtil class (this lives in the Sitecore namespace in Sitecore.Kernel.dll and isn’t as advanced as the Sitecore.Configuration.Factory class as it won’t instantiate nested objects defined in configuration as does the Sitecore Configuration Factory), I built the following Command which will decorate Commands defined in Sitecore configuration:

using System.Xml;

using Sitecore.Configuration;
using Sitecore.Diagnostics;
using Sitecore.Shell.Framework.Commands;
using Sitecore.Web.UI.HtmlControls;
using Sitecore.Xml;

namespace Sitecore.Sandbox.Shell.Framework.Commands
{
    public class ExtendedConfigCommand : Command
    {
        private Command command;
        protected Command Command
        {
            get
            {
                if(command == null)
                {
                    command = GetCommand();
                    EnsureCommand();
                }

                return command;
            }
        }
        
        protected virtual Command GetCommand()
        {
            XmlNode currentCommandNode = Factory.GetConfigNode(string.Format("commands/command[@name='{0}']", Name));
            string configPath = XmlUtil.GetAttribute("extendedCommandPath", currentCommandNode);
            Assert.IsNotNullOrEmpty(configPath, string.Format("The extendedCommandPath attribute must be set {0}!", currentCommandNode));
            Command command = Factory.CreateObject(configPath, false) as Command;
            Assert.IsNotNull(command, string.Format("The command defined at '{0}' was either not properly set or is not an instance of Sitecore.Shell.Framework.Commands.Command. Double-check it!", configPath));
            return command;
        }

        protected virtual void EnsureCommand()
        {
            Assert.IsNotNull(Command, "GetCommand() cannot return a null Sitecore.Shell.Framework.Commands.Command instance!");
        }

        public override void Execute(CommandContext context)
        {
            Command.Execute(context);
        }

        public override string GetClick(CommandContext context, string click)
        {
            return Command.GetClick(context, click);
        }

        public override string GetHeader(CommandContext context, string header)
        {
            return Command.GetHeader(context, header);
        }

        public override string GetIcon(CommandContext context, string icon)
        {
            return Command.GetIcon(context, icon);
        }

        public override Control[] GetSubmenuItems(CommandContext context)
        {
            return Command.GetSubmenuItems(context);
        }

        public override string GetToolTip(CommandContext context, string tooltip)
        {
            return Command.GetToolTip(context, tooltip);
        }

        public override string GetValue(CommandContext context, string value)
        {
            return Command.GetValue(context, value);
        }

        public override CommandState QueryState(CommandContext context)
        {
            return Command.QueryState(context);
        }
    }
}

The GetCommand() method reads the XmlNode for the current command, and gets the value set on its extendedCommandPath attribute. This value must to be a config path defined under the <sitecore> element in Sitecore configuration.

If the attribute doesn’t exist or is empty, or a Command instance isn’t properly created, an exception is thrown.

Otherwise, it is set on the Command property on the class.

All methods here delegate to the same methods on the Command stored in the Command property.

I then defined the following Command which will be used by the checkbox we are adding to the Sitecore Ribbon:

using Sitecore.Diagnostics;
using Sitecore.Shell.Framework.Commands;
using Sitecore.Web.UI.Sheer;

using Sitecore.Sandbox.Buckets.Settings;

namespace Sitecore.Sandbox.Buckets.Shell.Framework.Commands
{
    public class ToggleBucketedItemsCountCommand : Command
    {
        protected IBucketsContentEditorSettings BucketsContentEditorSettings { get; set; }

        public override void Execute(CommandContext context)
        {
            if (!AreItemBucketsEnabled())
            {
                return;
            }
            
            ToggleShowBucketedItemsCount();
            Reload();
        }

        protected virtual void ToggleShowBucketedItemsCount()
        {
            Assert.IsNotNull(BucketsContentEditorSettings, "BucketsContentEditorSettings must be defined in configuration!");
            BucketsContentEditorSettings.ShowBucketedItemsCount = !BucketsContentEditorSettings.ShowBucketedItemsCount;
        }

        protected virtual void Reload()
        {
            SheerResponse.SetLocation(string.Empty);
        }

        public override CommandState QueryState(CommandContext context)
        {
            if(!AreItemBucketsEnabled())
            {
                return CommandState.Hidden;
            }

            if(!ShouldShowBucketedItemsCount())
            {
                return CommandState.Enabled;
            }

            return CommandState.Down;
        }

        protected virtual bool AreItemBucketsEnabled()
        {
            Assert.IsNotNull(BucketsContentEditorSettings, "BucketsContentEditorSettings must be defined in configuration!");
            return BucketsContentEditorSettings.AreItemBucketsEnabled;
        }

        protected virtual bool ShouldShowBucketedItemsCount()
        {
            Assert.IsNotNull(BucketsContentEditorSettings, "BucketsContentEditorSettings must be defined in configuration!");
            return BucketsContentEditorSettings.ShowBucketedItemsCount;
        }
    }
}

The QueryState() method determines whether we should display the checkbox — it will only be displayed if the Item Buckets feature is on — and what the state of the checkbox should be — if we are currently showing Bucketed Items count, the checkbox will be checked (this is represented by CommandState.Down). Otherwise, it will be unchecked (this is represented by CommandState.Enabled).

The Execute() method encapsulates the logic of what we are to do when the user checks/unchecks the checkbox. It’s basically delegating to the ToggleShowBucketedItemsCount() method to toggle the value of whether we are to display the Bucketed Items count, and then reloads the Content Editor to refresh the display in the Content Tree.

I then had to define this checkbox in the Core database:

bucketed-items-count-checkbox-core

I’m not going to go into details of how the above works as I’ve written over a gazillion posts on the subject. I recommend having a read of one of these older posts.

After going back to my Master database, I saw the new checkbox in the Sitecore Ribbon:

buckted-items-count-new-checkbox

Since we could be dealing with thousands — if not millions — of Bucketed Items for each Item Bucket, we need a performant way to grab the count of these Items. In this solution, I am leveraging the Sitecore.ContentSearch API to get these counts though needed to add some custom
Computed Index Field classes:

using Sitecore.Buckets.Managers;
using Sitecore.Configuration;
using Sitecore.ContentSearch;
using Sitecore.ContentSearch.ComputedFields;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;

using Sitecore.Sandbox.Buckets.Util.Methods;

namespace Sitecore.Sandbox.Buckets.ContentSearch.ComputedFields
{
    public class IsBucketed : AbstractComputedIndexField
    {
        protected IItemBucketsFeatureMethods ItemBucketsFeatureMethods { get; private set; }

        public IsBucketed()
        {
            ItemBucketsFeatureMethods = GetItemBucketsFeatureMethods();
            Assert.IsNotNull(ItemBucketsFeatureMethods, "GetItemBucketsFeatureMethods() cannot return null!");
        }

        protected virtual IItemBucketsFeatureMethods GetItemBucketsFeatureMethods()
        {
            IItemBucketsFeatureMethods methods = Factory.CreateObject("buckets/methods/itemBucketsFeatureMethods", false) as IItemBucketsFeatureMethods;
            Assert.IsNotNull(methods, "the IItemBucketsFeatureMethods instance was not defined properly in /sitecore/buckets/methods/itemBucketsFeatureMethods!");
            return methods;
        }

        public override object ComputeFieldValue(IIndexable indexable)
        {
            Item item = indexable as SitecoreIndexableItem;
            if (item == null)
            {
                return null;
            }

            
            return IsBucketable(item) && IsItemContainedWithinBucket(item);
        }

        protected virtual bool IsBucketable(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            return BucketManager.IsBucketable(item);
        }

        protected virtual bool IsItemContainedWithinBucket(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            if(IsItemBucket(item))
            {
                return false;
            }

            return ItemBucketsFeatureMethods.IsItemContainedWithinBucket(item);
        }

        protected virtual bool IsItemBucket(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            if (!ItemBucketsFeatureMethods.IsItemBucket(item))
            {
                return false;
            }

            return true;
        }
    }
}

An instance of the class above ultimately determines if an Item is bucketed within an Item Bucket, and passes a boolean value to its caller denoting this via its ComputeFieldValue() method.

What determines whether an Item is bucketed? The code above says it’s bucketed only when the Item is bucketable and is contained within an Item Bucket.

The IsBucketable() method above ascertains whether the Item is bucketable by delegating to the IsBucketable() method on the BucketManager class in Sitecore.Buckets.dll.

The IsItemContainedWithinBucket() method determines if the Item is contained within an Item Bucket — you might be laughing as the name on the method is self-documenting — by delegating to the IsItemContainedWithinBucket() method on the IItemBucketsFeatureMethods instance — I’ve defined the code for this in this post so go have a look.

Moreover, the code does not consider Item Buckets to be Bucketed as that just doesn’t make much sense. πŸ˜‰ This would also give us an inaccurate count.

The following Computed Index Field’s ComputeFieldValue() method returns the string representation of the ancestor Item Bucket’s Sitecore.Data.ID for the Item — if it is contained within an Item Bucket:

using Sitecore.Configuration;
using Sitecore.ContentSearch;
using Sitecore.ContentSearch.ComputedFields;
using Sitecore.ContentSearch.Utilities;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;

using Sitecore.Sandbox.Buckets.Util.Methods;

namespace Sitecore.Sandbox.Buckets.ContentSearch.ComputedFields
{
    public class ItemBucketAncestorId : AbstractComputedIndexField
    {
        protected IItemBucketsFeatureMethods ItemBucketsFeatureMethods { get; private set; }

        public ItemBucketAncestorId()
        {
            ItemBucketsFeatureMethods = GetItemBucketsFeatureMethods();
            Assert.IsNotNull(ItemBucketsFeatureMethods, "GetItemBucketsFeatureMethods() cannot return null!");
        }

        protected virtual IItemBucketsFeatureMethods GetItemBucketsFeatureMethods()
        {
            IItemBucketsFeatureMethods methods = Factory.CreateObject("buckets/methods/itemBucketsFeatureMethods", false) as IItemBucketsFeatureMethods;
            Assert.IsNotNull(methods, "the IItemBucketsFeatureMethods instance was not defined properly in /sitecore/buckets/methods/itemBucketsFeatureMethods!");
            return methods;
        }

        public override object ComputeFieldValue(IIndexable indexable)
        {
            Item item = indexable as SitecoreIndexableItem;
            if (item == null)
            {
                return null;
            }

            Item itemBucketAncestor = GetItemBucketAncestor(item);
            if(itemBucketAncestor == null)
            {

                return null;
            }

            return NormalizeGuid(itemBucketAncestor.ID);
        }

        protected virtual Item GetItemBucketAncestor(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            if(IsItemBucket(item))
            {
                return null;
            }

            Item itemBucket = ItemBucketsFeatureMethods.GetItemBucket(item);
            if(!IsItemBucket(itemBucket))
            {
                return null;
            }

            return itemBucket;
        }

        protected virtual bool IsItemBucket(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            if (!ItemBucketsFeatureMethods.IsItemBucket(item))
            {
                return false;
            }

            return true;
        }

        protected virtual string NormalizeGuid(ID id)
        {
            return IdHelper.NormalizeGuid(id);
        }
    }
}

Not to go too much into details of the class above, it will only return an Item Bucket’s Sitecore.Data.ID as a string if the Item lives within an Item Bucket and is not itself an Item Bucket.

If the Item is not within an Item Bucket or is an Item Bucket, null is returned to the caller via the ComputeFieldValue() method.

I then created the following subclass of Sitecore.ContentSearch.SearchTypes.SearchResultItem — this lives in Sitecore.ContentSearch.dll — in order to use the values in the index that the previous Computed Field Index classes returned for their storage in the search index:

using System.ComponentModel;

using Sitecore.ContentSearch;
using Sitecore.ContentSearch.Converters;
using Sitecore.ContentSearch.SearchTypes;
using Sitecore.Data;

namespace Sitecore.Sandbox.Buckets.ContentSearch.SearchTypes
{
    public class BucketedSearchResultItem : SearchResultItem
    {
        [IndexField("item_bucket_ancestor_id")]
        [TypeConverter(typeof(IndexFieldIDValueConverter))]
        public ID ItemBucketAncestorId { get; set; }

        [IndexField("is_bucketed")]
        public bool IsBucketed { get; set; }
    }
}

Now, we need a class to get the Bucketed Item count for an Item Bucket. I defined the following interface for class implementations that do just that:

using Sitecore.Data.Items;

namespace Sitecore.Sandbox.Buckets.Providers.Items
{
    public interface IBucketedItemsCountProvider
    {
        int GetBucketedItemsCount(Item itemBucket);
    }
}

I then created the following class that implements the interface above:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Xml;

using Sitecore.Configuration;
using Sitecore.ContentSearch;
using Sitecore.ContentSearch.Linq;
using Sitecore.ContentSearch.Linq.Utilities;
using Sitecore.ContentSearch.SearchTypes;
using Sitecore.ContentSearch.Utilities;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Xml;

using Sitecore.Sandbox.Buckets.ContentSearch.SearchTypes;

namespace Sitecore.Sandbox.Buckets.Providers.Items
{
    public class BucketedItemsCountProvider : IBucketedItemsCountProvider
    {
        protected IDictionary<string, ISearchIndex> SearchIndexMap { get; private set; }

        public BucketedItemsCountProvider()
        {
            SearchIndexMap = CreateNewSearchIndexMap();
        }

        protected virtual IDictionary<string, ISearchIndex> CreateNewSearchIndexMap()
        {
            return new Dictionary<string, ISearchIndex>();
        }

        protected virtual void AddSearchIndexMap(XmlNode configNode)
        {
            if(configNode == null)
            {
                return;
            }

            string databaseName = XmlUtil.GetAttribute("database", configNode, null);
            Assert.IsNotNullOrEmpty(databaseName, "The database attribute on the searchIndexMap configuration element cannot be null or the empty string!");
            Assert.ArgumentCondition(!SearchIndexMap.ContainsKey(databaseName), "database", "The searchIndexMap configuration element's database attribute values must be unique!");

            Database database = Factory.GetDatabase(databaseName);
            Assert.IsNotNull(database, string.Format("No database exists with the name of '{0}'! Make sure the database attribute on your searchIndexMap configuration element is set correctly!", databaseName));
            
            string searchIndexName = XmlUtil.GetAttribute("searchIndex", configNode, null);
            Assert.IsNotNullOrEmpty(searchIndexName, "The searchIndex attribute on the searchIndexMap configuration element cannot be null or the empty string!");

            ISearchIndex searchIndex = GetSearchIndex(searchIndexName);
            Assert.IsNotNull(searchIndex, string.Format("No search index exists with the name of '{0}'! Make sure the searchIndex attribute on your searchIndexMap configuration element is set correctly", searchIndexName));

            SearchIndexMap.Add(databaseName, searchIndex);
        }

        public virtual int GetBucketedItemsCount(Item bucketItem)
        {
            Assert.ArgumentNotNull(bucketItem, "bucketItem");

            ISearchIndex searchIndex = GetSearchIndex();
            using (IProviderSearchContext searchContext = searchIndex.CreateSearchContext())
            {
                var predicate = GetSearchPredicate<BucketedSearchResultItem>(bucketItem.ID);
                IQueryable<SearchResultItem> query = searchContext.GetQueryable<BucketedSearchResultItem>().Filter(predicate);
                SearchResults<SearchResultItem> results = query.GetResults();
                return results.Count();
            }
        }

        protected virtual ISearchIndex GetSearchIndex()
        {
            string databaseName = GetContentDatabaseName();
            Assert.IsNotNullOrEmpty(databaseName, "The GetContentDatabaseName() method cannot return null or the empty string!");
            Assert.ArgumentCondition(SearchIndexMap.ContainsKey(databaseName), "databaseName", string.Format("There is no ISearchIndex instance mapped to the database: '{0}'!", databaseName));
            return SearchIndexMap[databaseName];
        }

        protected virtual string GetContentDatabaseName()
        {
            Database database = Context.ContentDatabase ?? Context.Database;
            Assert.IsNotNull(database, "Argggggh! There's no content database! Houston, we have a problem!");
            return database.Name;
        }

        protected virtual ISearchIndex GetSearchIndex(string searchIndexName)
        {
            Assert.ArgumentNotNullOrEmpty(searchIndexName, "searchIndexName");
            return ContentSearchManager.GetIndex(searchIndexName);
        }

        protected virtual Expression<Func<TSearchResultItem, bool>> GetSearchPredicate<TSearchResultItem>(ID itemBucketId) where TSearchResultItem : BucketedSearchResultItem
        {
            Assert.ArgumentCondition(!ID.IsNullOrEmpty(itemBucketId), "itemBucketId", "itemBucketId cannot be null or empty!");
            var predicate = PredicateBuilder.True<TSearchResultItem>();
            predicate = predicate.And(item => item.ItemBucketAncestorId == itemBucketId);
            predicate = predicate.And(item => item.IsBucketed);
            return predicate;
        }
    }
}

Ok, so what’s going on in the class above? The AddSearchIndexMap() method is called by the Sitecore Configuration Factory to add database-to-search-index mappings — have a look at the patch configuration file further below. The code is looking up the appropriate search index for the content/context database.

The GetBucketedItemsCount() method gets the “predicate” from the GetSearchPredicate() method which basically says “Hey, I want an Item that has an ancestor Item Bucket Sitecore.Data.ID which is the same as the Sitecore.Data.ID passed to the method, and also this Item should be bucketed”.

The GetBucketedItemsCount() method then employs the Sitecore.ContentSearch API to get the result-set of the Items for the query, and returns the count of those Items.

Just as Commands, DataViews in Sitecore are instantiated by the CreateObject() method on MainUtil. I want to utilize the Sitecore Configuration Factory instead so that my nested configuration elements are instantiated and injected into my custom DataView. I built the following interface to make that possible:

using System.Collections;

using Sitecore.Collections;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Globalization;

namespace Sitecore.Sandbox.Web.UI.HtmlControls.DataViews
{
    public interface IDataViewBaseExtender
    {
        void FilterItems(ref ArrayList children, string filter);

        void GetChildItems(ItemCollection items, Item item);

        Database GetDatabase();

        Item GetItemFromID(string id, Language language, Version version);

        Item GetParentItem(Item item);

        bool HasChildren(Item item, string filter);

        void Initialize(string parameters);

        bool IsAncestorOf(Item ancestor, Item item);

        void SortItems(ArrayList children, string sortBy, bool sortAscending);
    }
}

All of the methods in the above interface correspond to virtual methods defined on the Sitecore.Web.UI.HtmlControl.DataViewBase class in Sitecore.Kernel.dll.

I then built the following abstract class which inherits from any DataView class that inherits from Sitecore.Web.UI.HtmlControl.DataViewBase:

using System.Collections;

using Sitecore.Collections;
using Sitecore.Configuration;
using Sitecore.Data;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;
using Sitecore.Web.UI.HtmlControls;

namespace Sitecore.Sandbox.Web.UI.HtmlControls.DataViews
{
    public abstract class ExtendedDataView<TDataView> : DataViewBase where TDataView : DataViewBase
    {
        protected IDataViewBaseExtender DataViewBaseExtender { get; private set; }

        protected ExtendedDataView()
        {
            DataViewBaseExtender = GetDataViewBaseExtender();
            EnsureDataViewBaseExtender();
        }

        protected virtual IDataViewBaseExtender GetDataViewBaseExtender()
        {
            string configPath = GetDataViewBaseExtenderConfigPath();
            Assert.IsNotNullOrEmpty(configPath, "GetDataViewBaseExtenderConfigPath() cannot return null or the empty string!");
            IDataViewBaseExtender dataViewBaseExtender = Factory.CreateObject(configPath, false) as IDataViewBaseExtender;
            Assert.IsNotNull(dataViewBaseExtender, string.Format("the IDataViewBaseExtender instance was not defined properly in '{0}'!", configPath));
            return dataViewBaseExtender;
        }

        protected abstract string GetDataViewBaseExtenderConfigPath();

        protected virtual void EnsureDataViewBaseExtender()
        {
            Assert.IsNotNull(DataViewBaseExtender, "GetDataViewBaseExtender() cannot return a null IDataViewBaseExtender instance!");
        }

        protected override void FilterItems(ref ArrayList children, string filter)
        {
            DataViewBaseExtender.FilterItems(ref children, filter);
        }

        protected override void GetChildItems(ItemCollection items, Item item)
        {
            DataViewBaseExtender.GetChildItems(items, item);
        }

        public override Database GetDatabase()
        {
            return DataViewBaseExtender.GetDatabase();
        }

        protected override Item GetItemFromID(string id, Language language, Version version)
        {
            return DataViewBaseExtender.GetItemFromID(id, language, version);
        }

        protected override Item GetParentItem(Item item)
        {
            return DataViewBaseExtender.GetParentItem(item);
        }

        public override bool HasChildren(Item item, string filter)
        {
            return DataViewBaseExtender.HasChildren(item, filter);
        }

        public override void Initialize(string parameters)
        {
            DataViewBaseExtender.Initialize(parameters);
        }

        public override bool IsAncestorOf(Item ancestor, Item item)
        {
            return DataViewBaseExtender.IsAncestorOf(ancestor, item);
        }

        protected override void SortItems(ArrayList children, string sortBy, bool sortAscending)
        {
            DataViewBaseExtender.SortItems(children, sortBy, sortAscending);
        }
    }
}

The GetDataViewBaseExtender() method gets the config path for the configuration-defined IDataViewBaseExtender — these IDataViewBaseExtender configuration definitions may or may not have nested configuration elements which will also be instantiated by the Sitecore Configuration Factory — from the abstract GetDataViewBaseExtenderConfigPath() method (subclasses must define this method).

The GetDataViewBaseExtender() then employs the Sitecore Configuration Factory to create this IDataViewBaseExtender instance, and return it to the caller (it’s being called in the class’ constructor).

If the instance is null, an exception is thrown.

All other methods in the above class delegate to methods with the same name and parameters on the IDataViewBaseExtender instance.

I then built the following subclass of the abstract class above:

using Sitecore.Web.UI.HtmlControls;

namespace Sitecore.Sandbox.Web.UI.HtmlControls.DataViews
{
    public class ExtendedMasterDataView : ExtendedDataView<MasterDataView>
    {
        protected override string GetDataViewBaseExtenderConfigPath()
        {
            return "extendedDataViews/extendedMasterDataView";
        }
    }
}

The above class is used for extending the MasterDataView in Sitecore.

It’s now time for the “real deal” DataView that does what we want: show the Bucketed Item counts for Item Buckets. The instance of the following class does just that:

using System.Collections;

using Sitecore.Buckets.Forms;
using Sitecore.Collections;
using Sitecore.Data;
using Sitecore.Data.Fields;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;

using Sitecore.Sandbox.Buckets.Providers.Items;
using Sitecore.Sandbox.Buckets.Settings;
using Sitecore.Sandbox.Buckets.Util.Methods;
using Sitecore.Sandbox.Web.UI.HtmlControls.DataViews;

namespace Sitecore.Sandbox.Buckets.Forms
{
    public class BucketedItemsCountDataView : BucketDataView, IDataViewBaseExtender
    {
        protected IBucketsContentEditorSettings BucketsContentEditorSettings { get; set; }

        protected IItemBucketsFeatureMethods ItemBucketsFeatureMethods { get; set; }

        protected IBucketedItemsCountProvider BucketedItemsCountProvider { get; set; }

        protected string SingularBucketedItemsDisplayNameFormat { get; set; }

        protected string PluralBucketedItemsDisplayNameFormat { get; set; }

        void IDataViewBaseExtender.FilterItems(ref ArrayList children, string filter)
        {
            FilterItems(ref children, filter);
        }

        void IDataViewBaseExtender.GetChildItems(ItemCollection children, Item parent)
        {
            GetChildItems(children, parent);
        }

        protected override void GetChildItems(ItemCollection children, Item parent)
        {
            
            base.GetChildItems(children, parent);
            if(!ShouldShowBucketedItemsCount())
            {
                return;
            }

            for (int i = children.Count - 1; i >= 0; i--)
            {
                Item child = children[i];
                if (IsItemBucket(child))
                {
                    int count = GetBucketedItemsCount(child);
                    Item alteredItem = GetCountDisplayNameItem(child, count);
                    children.RemoveAt(i);
                    children.Insert(i, alteredItem);
                }
            }
        }

        protected virtual bool ShouldShowBucketedItemsCount()
        {
            Assert.IsNotNull(BucketsContentEditorSettings, "BucketsContentEditorSettings must be defined in configuration!");
            return BucketsContentEditorSettings.ShowBucketedItemsCount;
        }

        protected virtual bool IsItemBucket(Item item)
        {
            Assert.IsNotNull(ItemBucketsFeatureMethods, "ItemBucketsFeatureMethods must be set in configuration!");
            Assert.ArgumentNotNull(item, "item");
            return ItemBucketsFeatureMethods.IsItemBucket(item);
        }

        protected virtual int GetBucketedItemsCount(Item itemBucket)
        {
            Assert.IsNotNull(BucketedItemsCountProvider, "BucketedItemsCountProvider must be set in configuration!");
            Assert.ArgumentNotNull(itemBucket, "itemBucket");
            return BucketedItemsCountProvider.GetBucketedItemsCount(itemBucket);
        }

        protected virtual Item GetCountDisplayNameItem(Item item, int count)
        {
            FieldList fields = new FieldList();
            item.Fields.ReadAll();
            
            foreach (Field field in item.Fields)
            {
                fields.Add(field.ID, field.Value);
            }

            int bucketedCount = GetBucketedItemsCount(item);
            string displayName = GetItemNameWithBucketedCount(item, bucketedCount);
            ItemDefinition itemDefinition = new ItemDefinition(item.ID, displayName, item.TemplateID, ID.Null);
            return new Item(item.ID, new ItemData(itemDefinition, item.Language, item.Version, fields), item.Database) { RuntimeSettings = { Temporary = true } };
        }

        protected virtual string GetItemNameWithBucketedCount(Item item, int bucketedCount)
        {
            Assert.IsNotNull(SingularBucketedItemsDisplayNameFormat, "SingularBucketedItemsDisplayNameFormat must be set in configuration!");
            Assert.IsNotNull(PluralBucketedItemsDisplayNameFormat, "PluralBucketedItemsDisplayNameFormat must be set in configuration!");

            if (bucketedCount == 1)
            {
                return ReplaceTokens(SingularBucketedItemsDisplayNameFormat, item, bucketedCount);
            }

            return ReplaceTokens(PluralBucketedItemsDisplayNameFormat, item, bucketedCount);
        }

        protected virtual string ReplaceTokens(string format, Item item, int bucketedCount)
        {
            Assert.ArgumentNotNullOrEmpty(format, "format");
            Assert.ArgumentNotNull(item, "item");
            string replaced = format;
            replaced = replaced.Replace("$displayName", item.DisplayName);
            replaced = replaced.Replace("$bucketedCount", bucketedCount.ToString());
            return replaced;
        }

        Database IDataViewBaseExtender.GetDatabase()
        {
            return GetDatabase();
        }

        Item IDataViewBaseExtender.GetItemFromID(string id, Language language, Version version)
        {
            return GetItemFromID(id, language, version);
        }

        Item IDataViewBaseExtender.GetParentItem(Item item)
        {
            return GetParentItem(item);
        }

        bool IDataViewBaseExtender.HasChildren(Item item, string filter)
        {
            return HasChildren(item, filter);
        }

        void IDataViewBaseExtender.Initialize(string parameters)
        {
            Initialize(parameters);
        }

        bool IDataViewBaseExtender.IsAncestorOf(Item ancestor, Item item)
        {
            return IsAncestorOf(ancestor, item);
        }

        void IDataViewBaseExtender.SortItems(ArrayList children, string sortBy, bool sortAscending)
        {
            SortItems(children, sortBy, sortAscending);
        }
    }
}

You might be saying to yourself “Mike, what in the world is going on here?” πŸ˜‰ Let me explain by starting with the GetChildItems() method.

The GetChildItems() method is used to build up the collection of child Items that display in the Content Tree when you expand a parent node. It does this by populating the ItemCollection instance passed to it.

The particular implementation above is delegating to the base class’ implementation to get the list of child Items for display in the Content Tree.

If we should not show the Bucketed Items count — this is determined by the ShouldShowBucketedItemsCount() method which just returns the boolean value set on the ShowBucketedItemsCount property of the injected IBucketsContentEditorSettings instance — the code just exits.

If we are to show the Bucketed Items count, we iterate over the ItemCollection collection and see if any of these child Items are Item Buckets — this is determined by the IsItemBucket() method.

If we find an Item Bucket, we get its count of Bucketed Items via the GetBucketedItemsCount() method which delegates to the GetBucketedItemsCount() method on the injected IBucketedItemsCountProvider instance.

Once we have the count, we call the GetCountDisplayNameItem() method which populates a FieldList collection with all of the fields defined on the Item Bucket; call the GetItemNameWithBucketedCount() method to get the new display name to show in the Content Tree — this method determines which display name format to use depending on whether we should use singular or pluralized messaging, and expands value on tokens via the ReplaceTokens() method — these tokens are defined in the patch configuration file below; creates an ItemDefinition instance so we can set the new display name; and returns a new Sitecore.Data.Items.Item instance to the caller.

No, don’t worry, we aren’t adding a new Item in the content tree but creating a fake “wrapper” of the real one, and replacing this in the ItemCollection.

We also have to fully implement the IDataViewBaseExtender interface. For most methods, I just delegate to the corresponding methods defined on the base class except for the IDataViewBaseExtender.GetChildItems() method which uses the GetChildItems() method defined above.

I then bridged everything above together via the following patch configuration file:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <buckets>
      <extendedCommands>
        <toggleBucketedItemsCountCommand type="Sitecore.Sandbox.Buckets.Shell.Framework.Commands.ToggleBucketedItemsCountCommand, Sitecore.Sandbox" singleInstance="on">
          <BucketsContentEditorSettings ref="buckets/settings/bucketsContentEditorSettings" />
        </toggleBucketedItemsCountCommand>
      </extendedCommands>
      <providers>
        <items>
          <bucketedItemsCountProvider type="Sitecore.Sandbox.Buckets.Providers.Items.BucketedItemsCountProvider, Sitecore.Sandbox" singleInstance="true">
            <searchIndexMaps hint="raw:AddSearchIndexMap">
              <searchIndexMap database="master" searchIndex="sitecore_master_index" />
              <searchIndexMap database="web" searchIndex="sitecore_web_index" />
            </searchIndexMaps>
          </bucketedItemsCountProvider>
        </items>
      </providers>
      <settings>
        <bucketsContentEditorSettings type="Sitecore.Sandbox.Buckets.Settings.BucketsContentEditorSettings, Sitecore.Sandbox" singleInstance="true">
          <ItemBucketsFeatureDeterminer ref="determiners/features/itemBucketsFeatureDeterminer"/>
          <Registry ref="registries/registry" />
          <ShowBucketedItemsCountRegistryKey>/Current_User/UserOptions.View.ShowBucketedItemsCount</ShowBucketedItemsCountRegistryKey>
        </bucketsContentEditorSettings>
      </settings>
    </buckets>
    <commands>
      <command name="contenteditor:togglebucketeditemscount" type="Sitecore.Sandbox.Shell.Framework.Commands.ExtendedConfigCommand, Sitecore.Sandbox" extendedCommandPath="buckets/extendedCommands/toggleBucketedItemsCountCommand" />
    </commands>
    <contentSearch>
      <indexConfigurations>
        <defaultLuceneIndexConfiguration>
          <fieldMap>
            <fieldNames>
              <field fieldName="item_bucket_ancestor_id" storageType="YES" indexType="TOKENIZED" vectorType="NO" boost="1f" type="System.String" settingType="Sitecore.ContentSearch.LuceneProvider.LuceneSearchFieldConfiguration, Sitecore.ContentSearch.LuceneProvider">
                <analyzer type="Sitecore.ContentSearch.LuceneProvider.Analyzers.LowerCaseKeywordAnalyzer, Sitecore.ContentSearch.LuceneProvider" />
              </field>
              <field fieldName="is_bucketed" storageType="YES" indexType="TOKENIZED" vectorType="NO" boost="1f" type="System.Boolean" settingType="Sitecore.ContentSearch.LuceneProvider.LuceneSearchFieldConfiguration, Sitecore.ContentSearch.LuceneProvider" />
            </fieldNames>
          </fieldMap>
          <documentOptions>
            <fields hint="raw:AddComputedIndexField">
              <field fieldName="item_bucket_ancestor_id">Sitecore.Sandbox.Buckets.ContentSearch.ComputedFields.ItemBucketAncestorId, Sitecore.Sandbox</field>
              <field fieldName="is_bucketed">Sitecore.Sandbox.Buckets.ContentSearch.ComputedFields.IsBucketed, Sitecore.Sandbox</field>
            </fields>
          </documentOptions>
        </defaultLuceneIndexConfiguration>
      </indexConfigurations>
    </contentSearch>
    <dataviews>
      <dataview name="Master">
        <patch:attribute name="assembly">Sitecore.Sandbox</patch:attribute>
        <patch:attribute name="type">Sitecore.Sandbox.Web.UI.HtmlControls.DataViews.ExtendedMasterDataView</patch:attribute>
      </dataview>
    </dataviews>
    <extendedDataViews>
      <extendedMasterDataView type="Sitecore.Sandbox.Buckets.Forms.BucketedItemsCountDataView, Sitecore.Sandbox" singleInstance="true">
        <BucketsContentEditorSettings ref="buckets/settings/bucketsContentEditorSettings" />
        <ItemBucketsFeatureMethods ref="buckets/methods/itemBucketsFeatureMethods" />
        <BucketedItemsCountProvider ref="buckets/providers/items/bucketedItemsCountProvider" />
        <SingularBucketedItemsDisplayNameFormat>$displayName &lt;span style="font-style: italic; color: blue;"&gt;($bucketedCount bucketed item)&lt;span&gt;</SingularBucketedItemsDisplayNameFormat>
        <PluralBucketedItemsDisplayNameFormat>$displayName &lt;span style="font-style: italic; color: blue;"&gt;($bucketedCount bucketed items)&lt;span&gt;</PluralBucketedItemsDisplayNameFormat>
      </extendedMasterDataView>
    </extendedDataViews>
    <registries>
      <registry type="Sitecore.Sandbox.Web.UI.HtmlControls.Registries.Registry, Sitecore.Sandbox" singleInstance="true" />
    </registries>
  </sitecore>
</configuration>

bridge-collapse

Let’s see this in action:

bucketed-items-count-testing

As you can see, it is working as intended.

partay-hard

Magical, right?

magic

Well, not really — it just appears that way. πŸ˜‰

magic-not-really

If you have any thoughts on this, please drop a comment.

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Restrict Object Instantiation via the Singleton Pattern in Sitecore

This post is a continuation of a series of posts I’m putting together around using design patterns in Sitecore, and will show a “proof of concept” around using the Singleton pattern — a creational pattern which restricts the creation of a class to only one instance, and also provides a global reference to it.

In this “proof of concept”, I am using a Singleton which contains a method that will “un-parent” an Item — all of the Item’s children will become its siblings in the Sitecore content tree — and will utilize this in a command which will be wired-up to the Sitecore Ribbon. I honestly don’t see much utility in having such functionality in Sitecore — you just might πŸ™‚ — but the functionality itself is not the purpose of this post.

I first started out by creating the following class which serves as the Singleton:

using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Items
{
    public class ItemOperations
    {
        private static volatile ItemOperations current;
        
        private static object locker = new object();

        private ItemOperations() 
        { 
        }

        public static ItemOperations Current
        {
            get 
            {
                if (current == null) 
                {
                    lock (locker) 
                    {
                        if (current == null)
                        {
                            current = new ItemOperations();
                        }
                    }
                }

                return current;
            }
        }

        public void Unparent(Item item)
        {
            Assert.ArgumentNotNull(item, "item");
            if(!item.Children.Any())
            {
                return;
            }

            foreach(Item child in item.Children)
            {
                child.MoveTo(item.Parent);
            }
        }
    }
}

Before going into the details of why the class above is a Singleton, I want to point out that it contains one method — the Unparent() method — which iterates over all child Items of the Item passed to it, and moves them under the passed Item’s parent — this will move these child Items to the same level as their former parent.

You might be asking “what makes this a Singleton”? The first clue is the private constructor — this class cannot be instantiated by other classes. It can only be instantiated from within itself.

This instantiation is being done in the logic of its Current property. If the static private variable “current” is null, we “lock” an arbitrary object — this is done to make this multithreading “friendly” so that we can avoid collisions in the case when two different threads invoke the Current property at about the exact same time — and then create an instance of the ItemOperations class. This instance is then saved in the static variable “current”.

When the next call to the Current property is made on this class’ type, the “current” variable is already set, so the instance stored in it is returned to the caller.

The reason why the variable “current” and its associated property “Current” are static is to ensure these aren’t bound to an instance of the class but instead are bound to the class’ type, and the “Current” property can be accessed directly on the class’ name.

I then created the following subclass of Sitecore.Shell.Framework.Commands.Command which is needed for integration into the Sitecore Ribbon:

using System.Collections.Generic;
using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Shell.Framework.Commands;

using Sitecore.Sandbox.Items;

namespace Sitecore.Sandbox.Shell.Framework.Commands
{
    public class Unparent : Command
    {
        public Unparent()
        {
        }

        public override void Execute(CommandContext context)
        {
            Item item = GetItem(context);
            ItemOperations.Current.Unparent(item);
        }

        public override CommandState QueryState(CommandContext context)
        {
            Item item = GetItem(context);
            if (item == null || !item.Children.Any())
            {
                return CommandState.Hidden;
            }

            return CommandState.Enabled;
        }

        protected virtual Item GetItem(CommandContext context)
        {
            if(!context.Items.Any())
            {
                return null;
            }

            return context.Items.First();
        }
    }
}

The QueryState() method checks to see whether the selected Item in the Sitecore content tree has any children and returns the Hidden value on the Sitecore.Shell.Framework.Commands.CommandState enum — this lets the Sitecore Client code know that the button associated with this command should be hidden. If the Item does have children, the Enabled value on the Sitecore.Shell.Framework.Commands.CommandState enum is returned.

The Execute() method just passes the selected Item in the Sitecore content tree to the Unparent() method on the ItemOperations Singleton above — the Unparent() method is where the child Items are moved up a level.

I then had to register the command above with Sitecore via the following patch configuration file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <commands>
      <command name="item:Unparent" type="Sitecore.Sandbox.Shell.Framework.Commands.Unparent, Sitecore.Sandbox" />
    </commands>
  </sitecore>
</configuration>

Now that the above command is registered in Sitecore, we must bind it to Sitecore ribbon. I did that in the core database:

unparent-ribbon

I won’t go into details of the above as I’ve already covered how to do so in many of my previous posts — do have a look!

Let’s take this for a spin!

Let’s choose an Item with some child Items:

unparent-1

After clicking the “Unparent” button in the Ribbon, I saw the following:

unparent-2

As you can see, this Item was “un-parented”.

Ok, now that we had some fun with this, let’s have a serious discussion about the Singleton pattern — yeah, I know serious discussions aren’t always pleasant but what I have to say is pretty important regarding this pattern.

Although the Singleton pattern does make it easy to implement things quite fast, and does allow for less memory usage due to having less object instances floating around in memory, it unfortunately promotes tight coupling in your classes.

If you have to change something on the Singleton class itself — perhaps a method signature on it — you will have to also update every single class that references it. This can be quite costly from a development effort and painful — especially if the Singleton is being referenced in a gazillion places ( is gazillion a word? πŸ˜‰ ).

So, please do think twice before using this pattern — sure, it might be alright to use a Singleton in a pinch but do be sure it won’t lead to a maintenance nightmare for future development in your Sitecore solutions.

Utilize the Strategy Design Pattern for Content Editor Warnings in Sitecore

This post is a continuation of a series of posts I’m putting together around using design patterns in Sitecore implementations, and will show a “proof of concept” around using the Strategy pattern — a pattern where a family of “algorithms” (for simplicity you can think of these as classes that implement the same interface) which should be interchangeable when used by client code, and such holds true even when each do something completely different than others within the same family.

The Strategy pattern can serve as an alternative to the Template method pattern — a pattern where classes have an abstract base class that defines most of an β€œalgorithm” for how classes that inherit from it work but provides method stubs (abstract methods) and method hooks (virtual methods) for subclasses to implement or override — and will prove this in this post by providing an alternative solution to the one I had shown in my previous post on the Template method pattern.

In this “proof of concept”, I will be adding a processor to the <getContentEditorWarnings> pipeline in order to add custom content editor warnings for Items — if you are unfamiliar with content editor warnings in Sitecore, the following screenshot illustrates an “out of the box” content editor warning around publishing and workflow state:

content-editor-warning-example

To start, I am reusing the following interface and classes from my previous post on the Template method pattern:

using System.Collections.Generic;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings
{
    public interface IWarning
    {
        string Title { get; set; }

        string Message { get; set; }

        List<CommandLink> Links { get; set; }

        bool HasContent();

        IWarning Clone();
    }
}

Warnings will have a title, an error message for display, and a list of Sheer UI command links — the CommandLink class is defined further down in this post — to be displayed and invoked when clicked.

You might be asking why I am defining this when I can just use what’s available in the Sitecore API? Well, I want to inject these values via the Sitecore Configuration Factory, and hopefully this will become clear once you have a look at the Sitecore configuration file further down in this post.

Next, we have a class that implements the interface above:

using System.Collections.Generic;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings
{
    public class Warning : IWarning
    {
        public string Title { get; set; }

        public string Message { get; set; }

        public List<CommandLink> Links { get; set; }

        public Warning()
        {
            Links = new List<CommandLink>();
        }

        public bool HasContent()
        {
            return !string.IsNullOrWhiteSpace(Title)
                    || !string.IsNullOrWhiteSpace(Title)
                    || !string.IsNullOrWhiteSpace(Message);
        }

        public IWarning Clone()
        {
            IWarning clone = new Warning { Title = Title, Message = Message };
            foreach (CommandLink link in Links)
            {
                clone.Links.Add(new CommandLink { Text = link.Text, Command = link.Command });
            }

            return clone;
        }
    }
}

The HasContent() method just returns “true” if the instance has any content to display though this does not include CommandLinks — what’s the point in displaying these if there is no warning content to be displayed with them?

The Clone() method makes a new instance of the Warning class, and copies values into it — this is useful when defining tokens in strings that must be expanded before being displayed. If we expand them on the instance that is injected via the Sitecore Configuration Factory, the changed strings will persistent in memory until the application pool is recycled for the Sitecore instance.

The following class represents a Sheer UI command link to be displayed in the content editor warning so content editors/authors can take action on the warning:


namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings
{
    public class CommandLink
    {
        public string Text { get; set; }

        public string Command { get; set; }
    }
}

The Strategy pattern calls for a family of “algorithms” which can be interchangeably used. In order for us to achieve this, we need to define an interface for this family of “algorithms”:

using System.Collections.Generic;

using Sitecore.Data.Items;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern
{
    public interface IWarningsGenerator
    {
        Item Item { get; set; }

        IEnumerable<IWarning> Generate();
    }
}

Next, I created the following class that implements the interface above to ascertain whether a supplied Item has too many child Items:

using System.Collections.Generic;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern
{
    public class TooManyChildItemsWarningsGenerator : IWarningsGenerator
    {
        private int MaxNumberOfChildItems { get; set; }

        private IWarning Warning { get; set; }

        public Item Item { get; set; }

        public IEnumerable<IWarning> Generate()
        {
            AssertProperties();
            if (Item.Children.Count <= MaxNumberOfChildItems)
            {
                return new List<IWarning>();
            }

            return new[] { Warning };
        }

        private void AssertProperties()
        {
            Assert.ArgumentCondition(MaxNumberOfChildItems > 0, "MaxNumberOfChildItems", "MaxNumberOfChildItems must be set correctly in configuration!");
            Assert.IsNotNull(Warning, "Warning", "Warning must be set in configuration!");
            Assert.ArgumentCondition(Warning.HasContent(), "Warning", "Warning should have some fields populated from configuration!");
            Assert.IsNotNull(Item, "Item", "Item must be set!");
        }
    }
}

The “maximum number of child items allowed” value — this is stored in the MaxNumberOfChildItems integer property of the class — is passed to the class instance via the Sitecore Configuration Factory (you’ll see this defined in the Sitecore configuration file further down in this post).

The IWarning instance that is injected into the instance of this class will give content authors/editors the ability to convert the Item into an Item Bucket when it has too many child Items.

I then defined another class that implements the interface above — a class whose instances determine whether Items have invalid characters in their names:

using System.Collections.Generic;
using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern
{
    public class HasInvalidCharacetersInNameWarningsGenerator : IWarningsGenerator
    {
        private string CharacterSeparator { get; set; }

        private string Conjunction { get; set; }

        private List<string> InvalidCharacters { get; set; }

        private IWarning Warning { get; set; }

        public Item Item { get; set; }

        public HasInvalidCharacetersInNameWarningsGenerator()
        {
            InvalidCharacters = new List<string>();
        }

        public IEnumerable<IWarning> Generate()
        {
            AssertProperties();
            HashSet<string> charactersFound = new HashSet<string>();
            foreach (string character in InvalidCharacters)
            {
                if (Item.Name.Contains(character))
                {
                    charactersFound.Add(character.ToString());
                }
            }

            if(!charactersFound.Any())
            {
                return new List<IWarning>();
            }

            IWarning warning = Warning.Clone();
            string charactersFoundString = string.Join(CharacterSeparator, charactersFound);
            int lastSeparator = charactersFoundString.LastIndexOf(CharacterSeparator);
            if (lastSeparator < 0)
            {
                warning.Message = ReplaceInvalidCharactersToken(warning.Message, charactersFoundString);
                return new[] { warning };
            }

            warning.Message = ReplaceInvalidCharactersToken(warning.Message, Splice(charactersFoundString, lastSeparator, CharacterSeparator.Length, Conjunction));
            return new[] { warning };
        }

        private void AssertProperties()
        {
            Assert.IsNotNullOrEmpty(CharacterSeparator, "CharacterSeparator", "CharacterSeparator must be set in configuration!");
            Assert.ArgumentCondition(InvalidCharacters != null && InvalidCharacters.Any(), "InvalidCharacters", "InvalidCharacters must be set in configuration!");
            Assert.IsNotNull(Warning, "Warning", "Warning must be set in configuration!");
            Assert.ArgumentCondition(Warning.HasContent(), "Warning", "Warning should have some fields populated from configuration!");
            Assert.IsNotNull(Item, "Item", "Item must be set!");
        }

        private static string Splice(string value, int startIndex, int length, string replacement)
        {
            if(string.IsNullOrWhiteSpace(value))
            {
                return value;
            }

            return string.Concat(value.Substring(0, startIndex), replacement, value.Substring(startIndex + length));
        }

        private static string ReplaceInvalidCharactersToken(string value, string replacement)
        {
            return value.Replace("$invalidCharacters", replacement);
        }
    }
}

The above class will return an IWarning instance when an Item has invalid characters in its name — these invalid characters are defined in Sitecore configuration.

The Generate() method iterates over all invalid characters passed from Sitecore configuration and determines if they exist in the Item name. If they do, they are added to a HashSet<string> instance — I’m using a HashSet<string> to ensure the same character isn’t added more than once to the collection — which is used for constructing the warning message to be displayed to the content author/editor.

Once the Generate() method has iterated through all invalid characters, a string is built using the HashSet<string> instance, and is put in place wherever the $invalidCharacters token is defined in the Message property of the IWarning instance.

Now that we have our family of “algorithms” defined, we need a class to encapsulate and invoke these. I defined the following interface for classes that perform this role:

using System.Collections.Generic;

using Sitecore.Data.Items;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern
{
    public interface IWarningsGeneratorContext
    {
        IWarningsGenerator Generator { get; set; }

        IEnumerable<IWarning> GetWarnings(Item item);
    }
}

I then defined the following class which implements the interface above:

using System.Collections.Generic;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern
{
    public class WarningsGeneratorContext : IWarningsGeneratorContext
    {
        public IWarningsGenerator Generator { get; set; }

        public IEnumerable<IWarning> GetWarnings(Item item)
        {
            Assert.IsNotNull(Generator, "Generator", "Generator must be set!");
            Assert.ArgumentNotNull(item, "item");
            Generator.Item = item;
            return Generator.Generate();
        }
    }
}

Instances of the class above take in an instance of IWarningsGenerator via its Generator property — in a sense, we are “lock and loading” WarningsGeneratorContext instances to get them ready. Instances then pass a supplied Item instance to the IWarningsGenerator instance, and invoke its GetWarnings() method. This method returns a collection of IWarning instances.

In a way, the IWarningsGeneratorContext instances are really adapters for IWarningsGenerator instances — IWarningsGeneratorContext instances provide a bridge for client code to use IWarningsGenerator instances via its own little API.

Now that we have all of the stuff above — yes, I know, there is a lot of code in this post, and we’ll reflect on this at the end of the post — we need a class whose instance will serve as a <getContentEditorWarnings> pipeline processor:

using System.Collections.Generic;
using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;
using Sitecore.Pipelines.GetContentEditorWarnings;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern
{
    public class ContentEditorWarnings
    {
        private List<IWarningsGenerator> WarningsGenerators { get; set; }

        private IWarningsGeneratorContext WarningsGeneratorContext { get; set; }

        public ContentEditorWarnings()
        {
            WarningsGenerators = new List<IWarningsGenerator>();
        }

        public void Process(GetContentEditorWarningsArgs args)
        {
            AssertProperties();
            Assert.ArgumentNotNull(args, "args");
            Assert.ArgumentNotNull(args.Item, "args.Item");
            
            IEnumerable<IWarning> warnings = GetWarnings(args.Item);
            if(warnings == null || !warnings.Any())
            {
                return;
            }

            foreach(IWarning warning in warnings)
            {
                AddWarning(args, warning);
            }
        }

        private IEnumerable<IWarning> GetWarnings(Item item)
        {
            List<IWarning> warnings = new List<IWarning>();
            foreach(IWarningsGenerator generator in WarningsGenerators)
            {
                IEnumerable<IWarning> generatorWarnings = GetWarnings(generator, item);
                if(generatorWarnings != null && generatorWarnings.Any())
                {
                    warnings.AddRange(generatorWarnings);
                }
            }

            return warnings;
        }

        private IEnumerable<IWarning> GetWarnings(IWarningsGenerator generator, Item item)
        {
            WarningsGeneratorContext.Generator = generator;
            return WarningsGeneratorContext.GetWarnings(item);
        }

        private void AddWarning(GetContentEditorWarningsArgs args, IWarning warning)
        {
            if(!warning.HasContent())
            {
                return;
            }

            GetContentEditorWarningsArgs.ContentEditorWarning editorWarning = args.Add();
            if(!string.IsNullOrWhiteSpace(warning.Title))
            {
                editorWarning.Title = TranslateText(warning.Title);
            }

            if(!string.IsNullOrWhiteSpace(warning.Message))
            {
                editorWarning.Text = TranslateText(warning.Message);
            }

            if (!warning.Links.Any())
            {
                return;
            }
            
            foreach(CommandLink link in warning.Links)
            {
                editorWarning.AddOption(TranslateText(link.Text), link.Command);
            }
        }

        private string TranslateText(string text)
        {
            if(string.IsNullOrWhiteSpace(text))
            {
                return text;
            }

            return Translate.Text(text);
        }

        private void AssertProperties()
        {
            Assert.IsNotNull(WarningsGeneratorContext, "WarningsGeneratorContext", "WarningsGeneratorContext must be set in configuration!");
            Assert.ArgumentCondition(WarningsGenerators != null && WarningsGenerators.Any(), "WarningsGenerators", "At least one WarningsGenerator must be set in configuration!");
        }
    }
}

The Process() method is the main entry into the pipeline processor. The method delegates to the GetWarnings() method to get a collection of IWarning instances from all IWarningGenerator instances that were injected into the class instance via the Sitecore Configuration Factory.

The GetWarnings() method iterates over all IWarningsGenerator instances, and passes each to the other GetWarnings() method overload which basically sets the IWarningGenerator on the IWarningsGeneratorContext instance, and invokes its GetWarnings() method with the supplied Item instance.

Once all IWarning instances have been collected, the Process() method iterates over the IWarning collection, and adds them to the GetContentEditorWarningsArgs instance via the AddWarning() method.

I then registered everything above in Sitecore using the following Sitecore patch configuration file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <pipelines>
      <getContentEditorWarnings>
        <processor type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern.ContentEditorWarnings, Sitecore.Sandbox">
          <WarningsGenerators hint="list">
            <WarningsGenerator type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern.TooManyChildItemsWarningsGenerator, Sitecore.Sandbox">
              <MaxNumberOfChildItems>20</MaxNumberOfChildItems>
              <Warning type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Warning, Sitecore.Sandbox">
                <Title>This Item has too many child items!</Title>
                <Message>Please consider converting this Item into an Item Bucket.</Message>
                <Links hint="list">
                  <Link type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.CommandLink">
                    <Text>Convert to Item Bucket</Text>
                    <Command>item:bucket</Command>
                  </Link>
                </Links>
              </Warning>
            </WarningsGenerator>
            <WarningsGenerator type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern.HasInvalidCharacetersInNameWarningsGenerator, Sitecore.Sandbox">
              <CharacterSeparator>,&amp;nbsp;</CharacterSeparator>
              <Conjunction>&amp;nbsp;and&amp;nbsp;</Conjunction>
              <InvalidCharacters hint="list">
                <Character>-</Character>
                <Character>$</Character>
                <Character>1</Character>
              </InvalidCharacters>
              <Warning type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Warning, Sitecore.Sandbox">
                <Title>The name of this Item has invalid characters!</Title>
                <Message>The name of this Item contains $invalidCharacters. Please consider renaming the Item.</Message>
                <Links hint="list">
                  <Link type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.CommandLink">
                    <Text>Rename Item</Text>
                    <Command>item:rename</Command>
                  </Link>
                </Links>
              </Warning>
            </WarningsGenerator>
          </WarningsGenerators>
          <WarningsGeneratorContext type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Strategy_Pattern.WarningsGeneratorContext, Sitecore.Sandbox" />
        </processor>
      </getContentEditorWarnings>
    </pipelines>
  </sitecore>
</configuration>

Let’s test this out.

I set up an Item with more than 20 child Items, and gave it a name that includes -, $ and 1 — these are defined as invalid in the configuration file above:

strategy-1

As you can see, both warnings appear on the Item in the content editor.

Let’s convert the Item into an Item Bucket:

strategy-2

As you can see the Item is now an Item Bucket:

strategy-3

Let’s fix the Item’s name:

strategy-4

The Item’s name is now fixed, and there are no more content editor warnings:

strategy-5

You might be thinking “Mike, that is a lot of code — a significant amount over what you had shown in your previous post where you used the Template method pattern — so why bother with the Strategy pattern?”

Yes, there is more code here, and definitely more moving parts to the Strategy pattern over the Template method pattern.

So, what’s the benefit here?

Well, in the Template method pattern, subclasses are tightly coupled to their abstract base class. A change to the parent class could potentially break code in the subclasses, and this will require code in all subclasses to be changed. This could be quite a task if subclasses are defined in multiple projects that don’t reside in the same solution as the parent class.

The Strategy pattern forces loose coupling among all instances within the pattern thus reducing the likelihood that changes in one class will adversely affect others.

However, with that said, it does add complexity by introducing more code, so you should consider the pros and cons of using the Strategy pattern over the Template method pattern, or perhaps even decide if you should use a pattern to begin with.

Remember, the KISS principle should be followed wherever/whenever possible when designing and developing software.

If you have any thoughts on this, please drop a comment.

Employ the Template Method Design Pattern for Content Editor Warnings in Sitecore

This post is a continuation of a series of posts I’m putting together around using design patterns in Sitecore solutions, and will show a “proof of concept” around using the Template method pattern — a pattern where classes have an abstract base class that defines most of an “algorithm” for how classes that inherit from it work but provides method stubs — these are abstract methods that must be implemented by subclasses to “fill in the blanks” of the “algorithm” — and method hooks — these are virtual methods that can be overridden if needed.

In this “proof of concept”, I am tapping into the <getContentEditorWarnings> pipeline in order to add custom content editor warnings for Items — if you are unfamiliar with content editor warnings in Sitecore, the following screenshot illustrates an “out of the box” content editor warning around publishing and workflow state:

content-editor-warning-example

To start, I defined the following interface for classes that will contain content for warnings that will be displayed in the content editor:

using System.Collections.Generic;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings
{
    public interface IWarning
    {
        string Title { get; set; }

        string Message { get; set; }

        List<CommandLink> Links { get; set; }

        bool HasContent();

        IWarning Clone();
    }
}

Warnings will have a title, an error message for display, and a list of Sheer UI command links — the CommandLink class is defined further down this post — to be displayed and invoked when clicked.

You might be asking why I am defining this when I can just use what’s available in the Sitecore API? Well, I want to inject these values via the Sitecore Configuration Factory, and hopefully this will become clear once you have a look at the Sitecore configuration file further down in this post.

Next, I defined the following class that implements the interface above:

using System.Collections.Generic;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings
{
    public class Warning : IWarning
    {
        public string Title { get; set; }

        public string Message { get; set; }

        public List<CommandLink> Links { get; set; }

        public Warning()
        {
            Links = new List<CommandLink>();
        }

        public bool HasContent()
        {
            return !string.IsNullOrWhiteSpace(Title)
                    || !string.IsNullOrWhiteSpace(Title)
                    || !string.IsNullOrWhiteSpace(Message);
        }

        public IWarning Clone()
        {
            IWarning clone = new Warning { Title = Title, Message = Message };
            foreach (CommandLink link in Links)
            {
                clone.Links.Add(new CommandLink { Text = link.Text, Command = link.Command });
            }

            return clone;
        }
    }
}

The HasContent() method just returns “true” if the instance has any content to display though this does not include CommandLinks — what’s the point in displaying these if there is no warning content to be displayed with them?

The Clone() method makes a new instance of the Warning class, and copies values into it — this is useful when defining tokens in strings that must be expanded before being displayed. If we expand them on the instance that is injected via the Sitecore Configuration Factory, the changed strings will persistent in memory until the application pool is recycled for the Sitecore instance.

The following class represents a Sheer UI command link to be displayed in the content editor warning so content editors/authors can take action on the warning:


namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings
{
    public class CommandLink
    {
        public string Text { get; set; }

        public string Command { get; set; }
    }
}

I then built the following abstract class to serve as the base class for all classes whose instances will serve as a <getContentEditorWarnings> pipeline processor:

using System.Collections.Generic;
using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;
using Sitecore.Pipelines.GetContentEditorWarnings;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Template_Method_Pattern
{
    public abstract class ContentEditorWarnings
    {
        public void Process(GetContentEditorWarningsArgs args)
        {
            Assert.ArgumentNotNull(args, "args");
            Assert.ArgumentNotNull(args.Item, "args.Item");
            IEnumerable<IWarning> warnings = GetWarnings(args.Item);
            if(warnings == null || !warnings.Any())
            {
                return;
            }

            foreach(IWarning warning in warnings)
            {
                AddWarning(args, warning);
            }
        }

        protected abstract IEnumerable<IWarning> GetWarnings(Item item);

        private void AddWarning(GetContentEditorWarningsArgs args, IWarning warning)
        {
            if(!warning.HasContent())
            {
                return;
            }

            GetContentEditorWarningsArgs.ContentEditorWarning editorWarning = args.Add();
            if(!string.IsNullOrWhiteSpace(warning.Title))
            {
                editorWarning.Title = TranslateText(warning.Title);
            }

            if(!string.IsNullOrWhiteSpace(warning.Message))
            {
                editorWarning.Text = TranslateText(warning.Message);
            }

            if (!warning.Links.Any())
            {
                return;
            }
            
            foreach(CommandLink link in warning.Links)
            {
                editorWarning.AddOption(TranslateText(link.Text), link.Command);
            }
        }

        protected virtual string TranslateText(string text)
        {
            if(string.IsNullOrWhiteSpace(text))
            {
                return text;
            }

            return Translate.Text(text);
        }
    }
}

So what’s going on in this class? Well, the Process() method gets a collection of IWarnings from the GetWarnings() method — this method must be defined by subclasses of this class; iterates over them; and delegates to the AddWarning() method to add each to the GetContentEditorWarningsArgs instance.

The TranslateText() method calls the Text() method on the Sitecore.Globalization.Translate class — this lives in Sitecore.Kernel.dll — and is used when adding values on IWarning instances to the GetContentEditorWarningsArgs instance. This method is a hook, and can be overridden by subclasses if needed. I am not overriding this method on the subclasses further down in this post.

I then defined the following subclass of the class above to serve as a <getContentEditorWarnings> pipeline processor to warn content authors/editors if an Item has too many child Items:

using System.Collections.Generic;
using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Template_Method_Pattern
{
    public class TooManyChildItemsWarnings : ContentEditorWarnings
    {
        private int MaxNumberOfChildItems { get; set; }

        private IWarning Warning { get; set; }

        protected override IEnumerable<IWarning> GetWarnings(Item item)
        {
            AssertProperties();
            if(item.Children.Count <= MaxNumberOfChildItems)
            {
                return new List<IWarning>();
            }

            return new[] { Warning };
        }

        private void AssertProperties()
        {
            Assert.ArgumentCondition(MaxNumberOfChildItems > 0, "MaxNumberOfChildItems", "MaxNumberOfChildItems must be set correctly in configuration!");
            Assert.IsNotNull(Warning, "Warning", "Warning must be set in configuration!");
            Assert.ArgumentCondition(Warning.HasContent(), "Warning", "Warning should have some fields populated from configuration!");
        }
    }
}

The class above is getting its IWarning instance and maximum number of child Items value from Sitecore configuration.

The GetWarnings() method ascertains whether the Item has too many child Items and returns the IWarning instance when it does in a collection — I defined this to be a collection to allow <getContentEditorWarnings> pipeline processors subclassing the abstract base class above to return more than one warning if needed.

I then defined another subclass of the abstract class above to serve as another <getContentEditorWarnings> pipeline processor:

using System.Collections.Generic;
using System.Linq;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Template_Method_Pattern
{
    public class HasInvalidCharacetersInNameWarnings : ContentEditorWarnings
    {
        private string CharacterSeparator { get; set; }

        private string Conjunction { get; set; }

        private List<string> InvalidCharacters { get; set; }

        private IWarning Warning { get; set; }

        public HasInvalidCharacetersInNameWarnings()
        {
            InvalidCharacters = new List<string>();
        }

        protected override IEnumerable<IWarning> GetWarnings(Item item)
        {
            AssertProperties();
            HashSet<string> charactersFound = new HashSet<string>();
            foreach (string character in InvalidCharacters)
            {
                if(item.Name.Contains(character))
                {
                    charactersFound.Add(character.ToString());
                }
            }

            if(!charactersFound.Any())
            {
                return new List<IWarning>();
            }

            IWarning warning = Warning.Clone();
            string charactersFoundString = string.Join(CharacterSeparator, charactersFound);
            int lastSeparator = charactersFoundString.LastIndexOf(CharacterSeparator);
            if (lastSeparator < 0)
            {
                warning.Message = ReplaceInvalidCharactersToken(warning.Message, charactersFoundString);
                return new[] { warning };
            }

            warning.Message = ReplaceInvalidCharactersToken(warning.Message, Splice(charactersFoundString, lastSeparator, CharacterSeparator.Length, Conjunction));
            return new[] { warning };
        }

        private void AssertProperties()
        {
            Assert.IsNotNullOrEmpty(CharacterSeparator, "CharacterSeparator", "CharacterSeparator must be set in configuration!");
            Assert.ArgumentCondition(InvalidCharacters != null && InvalidCharacters.Any(), "InvalidCharacters", "InvalidCharacters must be set in configuration!");
            Assert.IsNotNull(Warning, "Warning", "Warning must be set in configuration!");
            Assert.ArgumentCondition(Warning.HasContent(), "Warning", "Warning should have some fields populated from configuration!");
        }

        private static string Splice(string value, int startIndex, int length, string replacement)
        {
            if(string.IsNullOrWhiteSpace(value))
            {
                return value;
            }

            return string.Concat(value.Substring(0, startIndex), replacement, value.Substring(startIndex + length));
        }

        private static string ReplaceInvalidCharactersToken(string value, string replacement)
        {
            return value.Replace("$invalidCharacters", replacement);
        }
    }
}

The above class will return an IWarning instance when an Item has invalid characters in its name — these invalid characters are defined in Sitecore configuration.

The GetWarnings() method iterates over all invalid characters passed from Sitecore configuration and determines if they exist in the Item name. If they do, they are added to a HashSet<string> instance — I’m using a HashSet<string> to ensure the same character isn’t added more than once to the collection — which is be used for constructing the warning message to be displayed to the content author/editor.

Once the GetWarnings() method has iterated through all invalid characters, a string is built using the HashSet<string> instance, and is put in place wherever the $invalidCharacters token is defined in the Message property of the IWarning instance.

I then registered everything above in Sitecore via the following patch configuration file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <pipelines>
      <getContentEditorWarnings>
        <processor type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Template_Method_Pattern.TooManyChildItemsWarnings, Sitecore.Sandbox">
          <MaxNumberOfChildItems>20</MaxNumberOfChildItems>
          <Warning type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Warning, Sitecore.Sandbox">
            <Title>This Item has too many child items!</Title>
            <Message>Please consider converting this Item into an Item Bucket.</Message>
            <Links hint="list">
              <Link type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.CommandLink">
                <Text>Convert to Item Bucket</Text>
                <Command>item:bucket</Command>
              </Link>
            </Links>
          </Warning>
        </processor>
        <processor type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Template_Method_Pattern.HasInvalidCharacetersInNameWarnings, Sitecore.Sandbox">
          <CharacterSeparator>,&amp;nbsp;</CharacterSeparator>
          <Conjunction>&amp;nbsp;and&amp;nbsp;</Conjunction>
          <InvalidCharacters hint="list">
            <Character>-</Character>
            <Character>$</Character>
            <Character>1</Character>
          </InvalidCharacters>
          <Warning type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.Warning, Sitecore.Sandbox">
            <Title>The name of this Item has invalid characters!</Title>
            <Message>The name of this Item contains $invalidCharacters. Please consider renaming the Item.</Message>
            <Links hint="list">
              <Link type="Sitecore.Sandbox.Pipelines.GetContentEditorWarnings.CommandLink">
                <Text>Rename Item</Text>
                <Command>item:rename</Command>
              </Link>
            </Links>
          </Warning>
        </processor>
      </getContentEditorWarnings>
    </pipelines>
  </sitecore>
</configuration>

As you can see, I am injecting warning data into my <getContentEditorWarnings> pipeline processors as well as other things which are used in code for each.

For the TooManyChildItemsWarnings <getContentEditorWarnings> pipeline processor, we are giving content authors/editors the ability to convert the Item into an Item bucket — we are injecting the item:bucket command via the configuration file above.

For the HasInvalidCharacetersInNameWarnings <getContentEditorWarnings> pipeline processor, we are passing in the Sheer UI command that will launch the Item Rename dialog to give content authors/editors the ability to rename the Item if it has invalid characters in its name.

Let’s see if this works.

I navigated to an Item in my content tree that has less than 20 child Items and has no invalid characters in its name:

no-content-editor-warnings

As you can see, there are no warnings.

Let’s go to another Item, one that not only has more than 20 child Items but also has invalid characters in its name:

both-warnings-appear

As you can see, both warnings are appearing for this Item.

Let’s now rename the Item:

rename-dialog

Great! Now the ‘invalid characters in name” warning is gone. Let’s convert this Item into an Item Bucket:

item-bucket-click-1

After clicking the ‘Convert to Item Bucket’ link, I saw the following dialog:

item-bucket-click-2

After clicking the ‘OK’ button, I saw the following progress dialog:

item-bucket-click-3

As you can see, the Item is now an Item Bucket, and both content editor warnings are gone:

item-bucket-click-4

If you have any thoughts on this, or have ideas on other places where you might want to employ the Template method pattern, please share in a comment.

Also, if you would like to see another example around adding a custom content editor warning in Sitecore, check out an older post of mine where I added one for expanding tokens in fields on an Item.

Until next time, keep on learning and keep on Sitecoring — Sitecoring is a legit verb, isn’t it? πŸ˜‰

Chain Together Sitecore Functionality Using the Chain-of-responsibility Design Pattern

This post is a continuation of a series of posts I’m putting together around using design patterns in Sitecore solutions, and will show a “proof of concept” around using the chain-of-responsibility pattern — a pattern where objects are linked together and are invoked in a cascading manner.

I decided to revisit a post I wrote over two years ago on chaining together client commands — these are invoked via the Sheer UI framework which drives how the ribbon, item context menu and other things work in Sitecore.

Earlier today — or yesterday depending on where you are — I began my code journey by building the following interface:

using Sitecore.Shell.Framework.Commands;

namespace Sitecore.Sandbox.Invokers.Commands
{
    public interface ICommandInvoker
    {
        bool HasCommand();

        void SetCommand(string commandName);

        void SetNextInvoker(ICommandInvoker nextInvoker);

        bool CanInvoke(CommandContext commandContext);

        void Invoke(CommandContext commandContext);
    }
}

The idea here is instances of classes that implement the interface above — let’s call them processing objects — will encapsulate instances of subclasses of Sitecore.Shell.Framework.Commands.Command — this is defined in Sitecore.Kernel.dll.

Each processing object will be linked to another processing object — I’m calling this other processing object the NextInvoker in code — which is invoked after the previous one.

Since the NextInvoker implements the interface above, it can also have its own NextInvoker thus chaining together a series of classes that implement the ICommandInvoker interface above.

I decided employ another design pattern in this solution — the Null Object pattern — and defined the following class whose instances will serve as a Null Object — I did this to reduce the amount of null checks in code (I should probably devote an entire post on this pattern):

using Sitecore.Diagnostics;
using Sitecore.Shell.Framework.Commands;

namespace Sitecore.Sandbox.Invokers.Commands
{
    public class NullCommandInvoker : ICommandInvoker
    {
        public NullCommandInvoker()
        {
        }

        public bool HasCommand()
        {
            return false;
        }

        public void SetCommand(string commandName)
        {
        }

        public void SetNextInvoker(ICommandInvoker nextInvoker)
        {
        }

        public bool CanInvoke(CommandContext commandContext)
        {
            return true;
        }

        public void Invoke(CommandContext commandContext)
        {
        }
    }
}

Basically, instances of the class above do nothing and can be invoked — why not? They don’t do actually do anything so no harm done, right? πŸ˜‰ — as can be seen in the CanInvoke() method.

I then created the following class whose instances will serve as the default processing objects:

using Sitecore.Configuration;
using Sitecore.Diagnostics;
using Sitecore.Shell.Framework.Commands;

namespace Sitecore.Sandbox.Invokers.Commands
{
    public class CommandInvoker : ICommandInvoker
    {
        private static ICommandInvoker NullCommandInvoker { get; set; }

        private Command Command { get; set; }

        private ICommandInvoker nextInvoker;
        private ICommandInvoker NextInvoker 
        { 
            get
            {
                return nextInvoker ?? NullCommandInvoker;
            }
            set
            {
                nextInvoker = value;
            }
        }

        static CommandInvoker()
        {
            NullCommandInvoker = CreateNullCommandInvoker();
        }

        public CommandInvoker()
        {
        }

        public bool HasCommand()
        {
            return Command != null;
        }

        public void SetCommand(string commandName)
        {
            Assert.ArgumentNotNullOrEmpty(commandName, "commandName");
            Command = GetCommand(commandName);
            Assert.IsNotNull(Command, "commandName", "commandName is not a valid command!");
        }

        public void SetNextInvoker(ICommandInvoker nextInvoker)
        {
            Assert.ArgumentNotNull(nextInvoker, "nextInvoker");
            NextInvoker = nextInvoker;
        }

        public bool CanInvoke(CommandContext commandContext)
        {
            Assert.ArgumentNotNull(commandContext, "commandContext");
            if(!HasCommand())
            {
                return false;
            }
            
            return Command.QueryState(commandContext) == CommandState.Enabled && NextInvoker.CanInvoke(commandContext);
        }

        public void Invoke(CommandContext commandContext)
        {
            Assert.ArgumentNotNull(commandContext, "commandContext");
            if(!HasCommand())
            {
                return;
            }

            Command.Execute(commandContext);
            NextInvoker.Invoke(commandContext);
        }

        protected virtual Command GetCommand(string commandName)
        {
            return CommandManager.GetCommand(commandName);
        }

        private static ICommandInvoker CreateNullCommandInvoker()
        {
            ICommandInvoker nullCommandInvoker = Factory.CreateObject("commandInvokers/nullCommandInvoker", true) as ICommandInvoker;
            Assert.IsNotNull(nullCommandInvoker, "nullCommandInvoker", "nullCommandInvoker must be set correctly in configuration!");
            return nullCommandInvoker;
        }
    }
}

There is a lot going on in the class above, so let me try to briefly capture the main things.

The SetCommand() method in the class above takes in the name of the command and delegates to the GetCommand() method which looks it up using the GetCommand() method on Sitecore.Shell.Framework.Commands.CommandManager in Sitecore.Kernel.dll.

The SetNextInvoker() method will chain the current CommandInvoker instance with another class instance that implements the ICommandInvoker interface — this is the NextInvoker.

The CanInvoke() method basically checks to see if the current CommandInvoker instance has a non-null Sitecore.Shell.Framework.Commands.Command instance set within it; ascertains whether the Sitecore.Shell.Framework.Commands.Command instance is enabled; and determines if the NextInvoker can be invoked.

The Invoke() method calls the Execute() method on the Sitecore.Shell.Framework.Commands.Command instance, and then calls the Invoke() method on the class instance’s NextInvoker.

One thing I’d like to point out is an instance of the Null Object class that was defined above is used when the NextInvoker is not set — this is why a null check is not done in the CanInvoke() and Invoke() methods on the NextInvoker instance.

I then built the following Sitecore.Shell.Framework.Commands.Command subclass which is to be wired-up to a menu option of some type in the Core database:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml;

using Sitecore.Collections;
using Sitecore.Configuration;
using Sitecore.Diagnostics;
using Sitecore.Shell.Framework.Commands;
using Sitecore.Web;

using Sitecore.Sandbox.Invokers.Commands;

namespace Sitecore.Sandbox.Shell.Framework.Commands
{
    public class ChainOfResponsibilityCommand : Command
    {
        private ICommandInvoker commandInvoker;
        private ICommandInvoker CommandInvoker 
        { 
            get
            {
                if(commandInvoker == null)
                {
                    commandInvoker = GetCommandInvoker();
                }

                return commandInvoker;
            }
        }

        public override void Execute(CommandContext context)
        {
            if (!CommandInvoker.CanInvoke(context))
            {
                return;
            }

            CommandInvoker.Invoke(context);
        }

        public override CommandState QueryState(CommandContext context)
        {
            if(!CommandInvoker.CanInvoke(context))
            {
                return CommandState.Hidden;
            }

            return CommandState.Enabled;
        }

        private ICommandInvoker GetCommandInvoker()
        {
            ICommandInvoker firstInvoker = CreateNewCommandInvoker();
            IEnumerable<string> commandNames = GetCommandNames(GetParameters());
            if(commandNames == null || !commandNames.Any())
            {
                return firstInvoker;
            }
            
            ICommandInvoker invoker = firstInvoker;
            invoker.SetCommand(commandNames.First());
            commandNames = commandNames.Skip(1).ToList();
            if (!commandNames.Any())
            {
                return firstInvoker;
            }

            foreach(string commandName in commandNames)
            {
                ICommandInvoker nextInvoker = CreateNewCommandInvoker();
                nextInvoker.SetCommand(commandName);
                invoker.SetNextInvoker(nextInvoker);
                invoker = nextInvoker;
            }

            return firstInvoker;
        }

        private IEnumerable<string> GetCommandNames(SafeDictionary<string> parameters)
        {
            string commands = GetCommandsString(parameters);
            char[] delimiters = GetCommandsDelimiters(parameters);

            if (string.IsNullOrWhiteSpace(commands) || delimiters == null || !delimiters.Any())
            {
                return new List<string>();
            }

            return commands.Split(delimiters, StringSplitOptions.RemoveEmptyEntries);
        }

        protected virtual string GetCommandsString(SafeDictionary<string> parameters)
        {
            return parameters["commands"];
        }

        private char[] GetCommandsDelimiters(SafeDictionary<string> parameters)
        {
            string delimiters = GetDelimitersString(parameters);
            if (string.IsNullOrWhiteSpace(delimiters))
            {
                return new char[] { };
            }

            return GetDelimitersString(parameters).ToCharArray();
        }

        protected virtual string GetDelimitersString(SafeDictionary<string> parameters)
        {
            return parameters["delimiters"];
        }

        protected virtual SafeDictionary<string> GetParameters()
        {
            XmlNode xmlNode = Factory.GetConfigNode(string.Format("commands/command[@name='{0}']", Name));
            string parametersValue = GetAttributeValue(xmlNode, "parameters");
            if (string.IsNullOrWhiteSpace(parametersValue))
            {
                return new SafeDictionary<string>();
            }
           
            return WebUtil.ParseQueryString(xmlNode.Attributes["parameters"].Value);
        }

        private string GetAttributeValue(XmlNode xmlNode, string attributeName)
        {
            if (xmlNode == null || xmlNode.Attributes[attributeName] == null || string.IsNullOrWhiteSpace(xmlNode.Attributes[attributeName].Value))
            {
                return string.Empty;
            }

            return xmlNode.Attributes[attributeName].Value;
        }

        protected static ICommandInvoker CreateNewCommandInvoker()
        {
            ICommandInvoker commandInvoker = Factory.CreateObject("commandInvokers/defaultCommandInvoker", true) as ICommandInvoker;
            Assert.IsNotNull(commandInvoker, "commandInvoker", "commandInvoker must be set correctly in configuration!");
            return commandInvoker;
        }
    }
}

The Command above reads the list of commands to chain together from Sitecore configuration — this is coming from an attribute on the Command’s configuration element which you will see in the configuration file below — and builds up a linked list of ICommandInvoker instances via the GetCommandInvoker() method.

The QueryState() method simply checks to see if the linked list of ICommandInvoker instances can be invoked, and the Execute() — which also performs the same check as is done in the QueryState() method — ultimately calls the Invoke() method on the first ICommandInvoker instance — this will cascade throughout the entire linked list.

I then wired everything up in the following Sitecore configuration file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <commands>
      <command name="item:MoveRenamePublish" parameters="commands=item:moveto|item:rename|item:publish&amp;delimiters=|"  type="Sitecore.Sandbox.Shell.Framework.Commands.ChainOfResponsibilityCommand, Sitecore.Sandbox"/>
      <command name="item:MoveLastPublish" parameters="commands=item:movelast|item:publish&amp;delimiters=|"  type="Sitecore.Sandbox.Shell.Framework.Commands.ChainOfResponsibilityCommand, Sitecore.Sandbox"/>
    </commands>
    <commandInvokers>
      <defaultCommandInvoker type="Sitecore.Sandbox.Invokers.Commands.CommandInvoker, Sitecore.Sandbox" singleInstance="false" />
      <nullCommandInvoker type="Sitecore.Sandbox.Invokers.Commands.NullCommandInvoker, Sitecore.Sandbox" singleInstance="false" />
    </commandInvokers>
  </sitecore>
</configuration>

I defined two different commands in the above configuration file to test whether the ChainOfResponsibilityCommand class can be reused for multiple Sheer UI commands.

I then set up two different buttons in the ribbon for the two command elements in the configuration file above:

item:MoveRenamePublish:

move-rename-publish-ribbon-core

item:MoveLastPublish:

move-last-publish-ribbon-core

Let’s take this for a spin.

Let’s move, rename and publish the following Sitecore Item:

cat-page-one-move-rename-publish-1

I clicked the button, and was presented with this dialog:

cat-page-one-move-rename-publish-2

I was then prompted with this dialog after the Item was moved to the selected destination:

cat-page-one-move-rename-publish-3

I renamed the Item, and was prompted with the publishing dialog:

cat-page-one-move-rename-publish-4

Ok, that appears to be working. Let’s try out the other Ribbon button. Let’s try it on this Item:

sub-page-one-move-last-publish-1

After the Item was moved, I was prompted with the publishing dialog:

sub-page-one-move-last-publish-2

As you can see, this worked as well.

I will say that although I had fun implementing this solution, it is way more complex than the solution I had built over two years ago in my older post.

This brings up an important point I want to make regarding design patterns: don’t use a design pattern because it may seem like a cool thing to do, or because your crazy developer cousin who always carries around a copy of the Gang Of Four book on design patterns says all solutions should implement them always.

Use them wisely.

if you see an opportunity to use one where it will save time when introducing new features moving forward, or it makes it easy to swap-in/out features, then by all means go for it. Otherwise, the KISS principle is a better “rule of thumb” to follow.

If you have any thoughts on this, please drop a comment.

Expand Tokens on Items Using a Sitecore PowerShell Extensions Toolbox Script

Last Wednesday I had the opportunity of presenting Sitecore PowerShell Extensions (SPE) at the Milwaukee Sitecore Meetup. During this presentation, I demonstrated how quickly and easily one can add, execute and reuse PowerShell scripts in SPE, and I did this using version 3.0 of SPE on Sitecore XP 8.

During one segment of the presentation, I shared how one can seamlessly add scripts to the SPE Toolbox — a repository of utility scripts if you will — and used the following script when showing this:

<#
    .NAME
        Expand tokens in all content items
 
    .SYNOPSIS
        Expand tokens in all fields in all content items
    .NOTES
        Mike Reynolds
#>
 
$items = Get-ChildItem -Path "master:\sitecore\content" -Recurse
$items | ForEach-Object { $_.Fields.ReadAll() }
$items |  Expand-Token
Close-Window

The script above grabs all descendant Items under /sitecore/content/; iterates over them to ensure all field values are available — the ReadAll() method on the FieldCollection instance will ensure values from fields on the Item’s template’s Standard Values Item are pulled in for processing; and sends in these Items into the Expand-Token commandlet which comes “out of the box” with SPE.

The script also closes the processing dialog.

I then saved the above script into my Toolbox library in my SPE module:

toolbox-script-ise-save

Let’s try this out. Let’s find some Items with tokens in some fields. It looks like the Home Item has some:

home-tokens

Here’s another Item that also has tokens:

descendant-tokens

Let’s go to the SPE Toolbox, and click on our Toolbox utility:

toolbox-expand-tokens-click

As you can see the tokens were expanded on the Home Item:

home-tokens-expanded

Tokens were also expanded on the descendant Item:

descendant-tokens-expanded

If you have any thoughts and/or suggestions on this, or have ideas for other SPE Toolbox scripts, please drop a comment.

If you would like to watch the Milwaukee Sitecore Meetup presentation where I showed the above — you’ll also get to see some epic Sitecore PowerShell Extensions stuff from Adam Brauer, Senior Product Engineer at Active Commerce, in this presentation as well — have a look below:

If you would like to see another example of adding a script to the SPE Toolbox, please see my previous post on this subject.

Until next time, have a scriptaculous day!

Bucket and Unbucket Items via Custom Item Context Menu Options Using Sitecore PowerShell Extensions

Last Wednesday I was honored to present Sitecore PowerShell Extensions (SPE) at the Milwaukee Sitecore Meetup. My presentation was all about how easy it is to add, execute and reuse PowerShell scripts in SPE, and I showcased this using version 3.0 of SPE on Sitecore XP 8.

During the presentation, I demonstrated how one can go about adding custom Item Context Menu options using SPE, and did so with the following scripts which bucket and unbucket Sitecore Items:

 <#
    .NAME 
        Convert To Item Bucket

    .SYNOPSIS
        Converts the context item to an Item Bucket
     
    .NOTES
        Mike Reynolds
#>
 
$item = Get-Item .

if($item."__Is Bucket" -eq "1") {
   return 
}

Get-ChildItem . -Recurse | %{ $_.__Bucketable = "1" }
Invoke-ShellCommand -Name "item:bucket" -Item $item
Close-Window

The above PowerShell script basically checks to see if an Item is an Item Bucket and does nothing if it is. If the Item is not an Item Bucket, we make sure all sub-items are bucketable — we just tick the “__Bucketable” Checkbox field on them — and invoke the Sheer UI command for converting an Item into an Item Bucket — this is done via the Invoke-ShellCommand commandlet that ships with SPE — and then close the script execution dialog users are presented with when SPE executes a script in the Item Context Menu.

The following script does the exact opposite of the script above — it converts an Item Bucket back to a regular Sitecore Item using the Sheer UI command for unbucketing:

<#
    .NAME 
        Convert Item Bucket To A Regular Item

    .SYNOPSIS
        Converts an Item Bucket to a regular Item
     
    .NOTES
        Mike Reynolds
#>

$item = Get-Item .

if($item."__Is Bucket" -ne "1") {
   return 
}

Invoke-ShellCommand -Name "item:unbucket" -Item $item
Close-Window
 

I then saved the above scripts to a Context Menu integration point in a SPE module I created during the presentation using the SPE Integrated Scripting Environment (ISE) (to get to the ISE in SPE, go to Sitecore ==> Development Tools ==> PowerShell ISE in the Sitecore Start menu of the Sitecore Desktop):

Saved-context-menu-script

I’ve omitted screenshots on saving the “Convert Item Bucket To A Regular Item” script for brevity.

I then set rules in the “Show if rules are met or not defined” field on both Context Menu script Items — we only want the “Convert To Item Bucket” Context Menu option to show when the Item isn’t an Item Bucket, and the “Convert Item Bucket To A Regular Item” Context Menu option to show when the Item it is an Item Bucket:

The “Convert To Item Bucket” Context Menu item (this Item was saved to /sitecore/system/Modules/PowerShell/Script Library/SitecoreUG Module/Content Editor/Context Menu/Convert To Item Bucket in my Sitecore instance):

set-rules-convert-to-bucket

The “Convert Item Bucket To A Regular Item” Context Menu item:

set-rules-convert-to-unbucket

After saving the above, I navigated to an Item in my content tree that has sub-items, right-clicked on it, and clicked on the “Convert To Item Bucket” Context Menu option:

convert-to-bucket-right-click

I was then presented with a confirmation dialog:

convert-to-bucket-confirm

As you can see the Item is now an Item Bucket:

item-is-a-bucket

I right-clicked on the Item again, and clicked on the “Convert Item Bucket To A Regular Item” Context Menu option:

convert-to-unbucket-right-click

I was presented with another confirmation dialog:

convert-to-ubucket-confirm

As you can see the Item is no longer an Item Bucket:

no-longer-a-bucket

If you have any thoughts on this or ideas for other Context Menu PowerShell scripts for SPE, please drop a comment.

If you would like to watch the Milwaukee Sitecore Meetup presentation where I showed the above — you’ll also get to see some cool Sitecore PowerShell Extensions stuff from Adam Brauer, Senior Product Engineer at Active Commerce, in this presentation as well — have a look below:

Until next time, have a Sitecoretastic day!

Augment Configuration-defined Sitecore Functionality using the Composite Design Pattern

In a couple of my past posts — Synchronize IDTable Entries Across Multiple Sitecore Databases Using a Composite IDTableProvider and
Chain Together Sitecore Client Commands using a Composite Command — I used the Composite design pattern to chain together functionality in two or more classes with the same interface — by interface here, I don’t strictly mean a C# interface but any class that servers as a base class for others where all instances share the same methods — and had a thought: how could I go about making a generic solution to chain together any class type defined in Sitecore configuration?

As a “proof of concept” I came up with the following solution while taking a break from my judgely duties reviewing 2015 Sitecore Hackathon modules.

I first defined an interface for classes that will construct objects using the Sitecore Configuration Factory:

using System.Collections.Generic;
using System.Xml;

namespace Sitecore.Sandbox.Shared
{
    public interface IConfigurationFactoryInstances<TInstance>
    {
        void AddInstance(XmlNode source);

        IEnumerable<TInstance> GetInstances();
    }
}

The following class implements the methods defined in the interface above:

using System.Collections.Generic;
using System.Xml;

using Sitecore.Configuration;

namespace Sitecore.Sandbox.Shared
{
    public class ConfigurationFactoryInstances<TInstance> : IConfigurationFactoryInstances<TInstance> where TInstance : class
    {
        private IList<TInstance> Instances { get; set; }

        public ConfigurationFactoryInstances()
        {
            Instances = new List<TInstance>();
        }

        public virtual IEnumerable<TInstance> GetInstances()
        {
            return Instances;
        }

        public void AddInstance(XmlNode configNode)
        {
            TInstance instance = CreateInstance(configNode);
            if (instance == null)
            {
                return;
            }

            Instances.Add(instance);
        }

        protected virtual TInstance CreateInstance(XmlNode configNode)
        {
            if (configNode == null)
            {
                return null;
            }

            TInstance instance = Factory.CreateObject(configNode, true) as TInstance;
            if (instance == null)
            {
                return null;
            }

            return instance;
        }
    }
}

The AddInstance() method in the class above — along with the help of the CreateInstance() method — takes in a System.Xml.XmlNode instance and attempts to create an instance of the type denoted by TInstance using the Sitecore Configuration Factory. If the instance was successfully created (i.e. it’s not null), it is added to a list.

The GetInstances() method in the class above just returns the list of the instances that were added by the AddInstance() method.

Since I’ve been posting a lot of meme images on Twitter lately — you can see the evidence here — I’ve decided to have a little fun tonight with this “proof of concept”, and created the following composite MediaProvider:

using System.Xml;

using Sitecore.Data.Items;
using Sitecore.Resources.Media;

using Sitecore.Sandbox.Shared;

namespace Sitecore.Sandbox.Resources.Media
{
    public class CompositeMediaProvider : MediaProvider
    {
        private static IConfigurationFactoryInstances<MediaProvider> Instances { get; set; }

        static CompositeMediaProvider()
        {
            Instances = new ConfigurationFactoryInstances<MediaProvider>();
        }

        public override string GetMediaUrl(MediaItem item, MediaUrlOptions options)
        {
            foreach (MediaProvider mediaProvider in Instances.GetInstances())
            {
                string url = mediaProvider.GetMediaUrl(item, options);
                if(!string.IsNullOrWhiteSpace(url))
                {
                    return url;
                }
            }

            return base.GetMediaUrl(item, options);
        }

        protected virtual void AddMediaProvider(XmlNode configNode)
        {
            Instances.AddInstance(configNode);
        }
    }
}

The AddMediaProvider() method in the class above adds new instances of Sitecore.Resources.Media.MediaProvider through delegation to an instance of the ConfigurationFactoryInstances class. The Sitecore Configuration Factory will call the AddMediaProvider() method since it’s defined in the patch include configuration file shown later in this post

The GetMediaUrl() method iterates over all instances of Sitecore.Resources.Media.MediaProvider that were created and stored by the ConfigurationFactoryInstances instance, and calls each of their GetMediaUrl() methods. The first non-null or empty URL from one of these “inner” instances is returned to the caller. If none of the instances return a URL, then the class above returns the value given by its base class’ GetMediaUrl() method.

I then spun up three MediaProvider classes to serve up specific image URLs of John West — I found these somewhere on the internet πŸ˜‰ — when they encounter media Items with specific names (I am not advocating that anyone hard-codes anything like this — these classes are only here to serve as examples):

using System;

using Sitecore.Data.Items;
using Sitecore.Resources.Media;

namespace Sitecore.Sandbox.Resources.Media
{
    public class JohnWestOneMediaProvider : MediaProvider
    {
        public override string GetMediaUrl(MediaItem item, MediaUrlOptions options)
        {
            if(item.Name.Equals("john-west-1", StringComparison.CurrentCultureIgnoreCase))
            {
                return "http://cdn.meme.am/instances/500x/43030540.jpg";
            }

            return string.Empty;
        }
    }
}

using System;

using Sitecore.Data.Items;
using Sitecore.Resources.Media;

namespace Sitecore.Sandbox.Resources.Media
{
    public class JohnWestTwoMediaProvider : MediaProvider
    {
        public override string GetMediaUrl(MediaItem item, MediaUrlOptions options)
        {
            if (item.Name.Equals("john-west-2", StringComparison.CurrentCultureIgnoreCase))
            {
                return "http://cdn.meme.am/instances/500x/43044627.jpg";
            }

            return string.Empty;
        }
    }
}
using System;

using Sitecore.Data.Items;
using Sitecore.Resources.Media;

namespace Sitecore.Sandbox.Resources.Media
{
    public class JohnWestThreeMediaProvider : MediaProvider
    {
        public override string GetMediaUrl(MediaItem item, MediaUrlOptions options)
        {
            if (item.Name.Equals("john-west-3", StringComparison.CurrentCultureIgnoreCase))
            {
                return "http://cdn.meme.am/instances/500x/43030625.jpg";
            }

            return string.Empty;
        }
    }
}

I then registered all of the above in Sitecore using a patch configuration file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <mediaLibrary>
      <mediaProvider>
        <patch:attribute name="type">Sitecore.Sandbox.Resources.Media.CompositeMediaProvider, Sitecore.Sandbox</patch:attribute>
        <mediaProviders hint="raw:AddMediaProvider">
          <mediaProvider type="Sitecore.Sandbox.Resources.Media.JohnWestOneMediaProvider, Sitecore.Sandbox" />
          <mediaProvider type="Sitecore.Sandbox.Resources.Media.JohnWestTwoMediaProvider, Sitecore.Sandbox" />
          <mediaProvider type="Sitecore.Sandbox.Resources.Media.JohnWestThreeMediaProvider, Sitecore.Sandbox" />
          <mediaProvider type="Sitecore.Resources.Media.MediaProvider, Sitecore.Kernel" />
        </mediaProviders>
      </mediaProvider>
    </mediaLibrary>
  </sitecore>
</configuration>

Let’s see this in action!

To test, I uploaded four identical photos of John West to the Media Library:

four-jw-media-library

I then inserted these into a Rich Text field on my home Item:

rte-jw-times-four

I saved my home Item and published everything. Once the publish was finished, I navigated to my home page and saw the following:

four-jw-home-page

As you can see, the three custom John West MediaProvider class instances served up their URLs, and the “out of the box” Sitecore.Resources.Media.MediaProvider instance served up its URL on the last image.

If you have any thoughts on this, please share in a comment.

Until next time, have a Sitecoretastic day!

Chain Source and Clone Items Together in Sitecore Workflow

Two months ago, I worked on a project where I had to find a solution to chain source Items and their clones together in Sitecore workflow — don’t worry, the clone Items were “locked down” by being protected so content authors cannot make changes to content on the clones — the clones serve as content copies of their source Items for a multi-site solution in a single Sitecore instance.

After some research, a few mistakes — well, maybe more than a few πŸ˜‰ — and massive help from Oleg Burov, Escalation Engineer at Sitecore USA, I put together a subclass of Sitecore.Workflows.Simple.Workflow — this lives in Sitecore.Kernel.dll — similar to the following:

using Sitecore.Data.Items;
using Sitecore.Workflows;
using Sitecore.Workflows.Simple;

namespace Sitecore.Sandbox.Workflows.Simple
{
    public class ChainSourceClonesWorkflow : Workflow 
    {
        public ChainSourceClonesWorkflow(string workflowID, WorkflowProvider owner)
            : base(workflowID, owner)
        {

        }
        public override WorkflowResult Execute(string commandID, Item item, string comments, bool allowUI, params object[] parameters)
        {
            WorkflowResult result = base.Execute(commandID, item, comments, allowUI, parameters);
            foreach (Item clone in item.GetClones())
            {
                base.Execute(commandID, clone, comments, allowUI, parameters);
            }

            return result;
        }
    }
}

The Execute() method above basically moves the passed Item through to the next workflow state by calling the base class’ Execute() method, and grabs all clones for the passed Item — each are also pushed through to the next workflow state via the base class’ Execute() method.

Workflow instances are created by Sitecore.Workflows.Simple.WorkflowProvider. I created the following class to return an instance of the ChainSourceClonesWorkflow class above:

using Sitecore.Workflows;
using Sitecore.Workflows.Simple;

namespace Sitecore.Sandbox.Workflows.Simple
{
    public class ChainSourceClonesWorkflowProvider : WorkflowProvider
    {
        public ChainSourceClonesWorkflowProvider(string databaseName, HistoryStore historyStore)
            : base(databaseName, historyStore)
        {
        }

        protected override IWorkflow InstantiateWorkflow(string workflowId, WorkflowProvider owner)
        {
            return new ChainSourceClonesWorkflow(workflowId, owner);
        }
    }
}

I then replaced the “out of the box” WorkflowProvider with the one defined above using the following configuration file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <databases>
      <database id="master">
        <workflowProvider type="Sitecore.Workflows.Simple.WorkflowProvider, Sitecore.Kernel">
          <patch:attribute name="type">Sitecore.Sandbox.Workflows.Simple.ChainSourceClonesWorkflowProvider, Sitecore.Sandbox</patch:attribute>
        </workflowProvider>
      </database>
    </databases>
  </sitecore>
</configuration>

Let’s take this for a spin!

I first started with a source and clone in a “Draft” workflow state:

source-clone-draft

Let’s push the source — and hopefully clone πŸ˜‰ — through to the next workflow state by submitting it:

source-clone-submit

As you can see, both are “Awaiting Approval”:

source-clone-awaiting-approval

Let’s approve them:

source-clone-approve

As you can see, both are approved:

source-clone-approved

If you have any thoughts or comments on this, or know of ways to improve the code above, please drop a comment.

Also, keep in mind the paradigm above is not ideal when content authors are able to make content changes to clones which differ from their source Items. In that scenario, it would be best to let source and clone Items’ workflow be independent.

Make Bulk Item Updates using Sitecore PowerShell Extensions

In my Sitecore PowerShell Extensions presentation at the Sitecore User Group Conference 2014, I demonstrated how simple it is to make bulk Item updates — perform the same update to multiple Sitecore items — using a simple PowerShell script, and thought I would write down what I had shown.

Sadly, I do not remember which script I had shared with the audience — the scratchpad text file I referenced during my presentation contains multiple scripts for making bulk updates to Items (if you attended my talk, and remember exactly what I had shown, please drop a comment).

Since I cannot recall which script I had shown — please forgive me πŸ˜‰ — let’s look at the following PowerShell script (this might be the script I had shown):

@(Get-Item .) + (Get-ChildItem -r .) | ForEach-Object { Expand-Token $_ }

This script grabs the context Item — this is denoted by a period — within the PowerShell ISE via the Get-Item command, and puts it into an array so that we can concatenate it with an array of all of its descendants — this is returned by the Get-ChildItem command with the -r parameter (r stands for recursive). The script then iterates over all Items in the resulting array, passes each to the Expand-Token command — this command is offered “out of the box” in Sitecore PowerShell Extensions — which expands tokens in every field on the Item.

Let’s see this in action!

My home Item has some tokens in its Title field:

home-tokens

One of its descendants also has tokens in its Title field:

descendant-tokens

I opened up the PowerShell ISE, wrote my script, and executed:

powershell-ise-tokens

As you can see, the tokens on the home Item were expanded:

home-tokens-expanded

They were also expanded on the home Item’s descendant:

descendant-tokens-expanded

If you have any thoughts or questions on this, please share in a comment.