In my previous post, I gave a solution which I leverages the Sitecore Rules Engine to create a custom Item Buckets folder structure for storing bucketable Items.

Last night, I had a thought: what if you needed to know which “algorithm” created a given bucket folder structure for an Item Bucket? How could we go about conveying this type of information?

Immediately, the Sitecore Gutter came to mind — it’s a great way to communicate this type of information visually.

Before I move forward on the solution I started last night and completed today, let me explain what the Sitecore Gutter is, just in case you are unfamiliar with this feature.

The Sitecore Gutter lives here in the Content Editor:

If you right-click in this area, you get a context menu to turn on/off Gutter indicators:

I turned on the Item Buckets Gutter indicator, and now can see which Items are Buckets:

There is a huge body of blog posts out on the interwebs which give examples on adding to the Sitecore Gutter. Here are a few posts from some fellow Sitecore MVPs which I highly recommend reading (in order of publish date):

• The Sitecore Gutter by Sitecore MVP Robin Hermanussen
• Creating a Gutter Icon for Proxies by Sitecore MVP Dan Solovay
• Sitecore Gutter Icon to Indicate an Item is a Page by Sitecore MVP Mark Ursino
• Display item publication status in the Sitecore gutter by Sitecore MVP Ruud van Falier

I also wrote a post on how to add to the Sitecore Gutter using the Sitecore PowerShell Extensions module. I recommend having a look at that as well. 😉

Now that we are well-versed — or “wicked smaht” as we Bostonians would alternatively say — on what the Sitecore Gutter is, let’s move on to the solution I came up with.

Just a “heads up”: there is a lot of code in this solution so don’t freak out and/or get too overwhelmed. Stay the course. 😉

I first explored Sitecore.Buckets.Gutters.BucketGutter in Sitecore.Buckets.dll to see if I should take note of anything special I need to know about when creating custom Sitecore.Shell.Applications.ContentEditor.Gutters.GutterRenderer — this lives in Sitecore.Kernel.dll and needs to be subclassed when adding to the Sitecore Gutter — subclasses for Item Buckets.

I noticed there is code in there which ascertains whether the Item Buckets feature is turned on/off, and obviously returns a null instance of Sitecore.Shell.Applications.ContentEditor.Gutters.GutterIconDescriptor — this lives in Sitecore.Kernel.dll — via its GetIconDescriptor() method.

I decided I needed to a way to also ascertain this. I came up with the following interface for classes that determined whether a feature is enabled or not:

namespace Sitecore.Sandbox.Determiners.Features
{
    public interface IFeatureDeterminer
    {
        bool IsEnabled();
    }
}

I then implemented the above interface with the following class:

using Sitecore.ContentSearch;
using Sitecore.ContentSearch.Utilities;

using Sitecore.Sandbox.Determiners.Features;

namespace Sitecore.Sandbox.Buckets.Determiners.Features
{
    public class ItemBucketsFeatureDeterminer : IFeatureDeterminer
    {
        public virtual bool IsEnabled()
        {
            return ContentSearchManager.Locator.GetInstance<IContentSearchConfigurationSettings>().ItemBucketsEnabled();
        }
    }
}

The code in the IsEnabled() method basically returns a boolean indicating whether the Item Buckets feature is turned on/off.

We now need classes whose instances can ascertain whether a bucketed Item’s path matches the paths generated by the bucketing algorithms they represent. I created the following class whose instances would serve as a parameters object to these objects:

using System;

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

namespace Sitecore.Sandbox.Buckets.Ascertainers
{
    public class BucketFolderPathAscertainerParameters
    {
        public Item BucketItem { get; set; }

        public Item BucketedItem { get; set; }

        public DateTime CreationDateOfNewItem { get; set; }
    }
}

We’re just going to pass the Item Bucket, the bucketed Item and the creation date of the bucketed Item.

Next, we need those objects that ascertain whether a given Item Bucket uses a particular bucketing algorithm for its folder structure. I created the following interface for classes whose instances do just that:

namespace Sitecore.Sandbox.Buckets.Ascertainers
{
    public interface IBucketFolderPathAscertainer
    {
        string GetIcon();

        string GetToolTip();

        bool IsFolderPathMatch(BucketFolderPathAscertainerParameters parameters);
    }
}

After implementing two classes which implemented the interface above, I noticed some code similarities between them, and decided to employ Martin Fowler‘s refactoring technique Pull Up Method to move up these code similarities into a base class — I highly recommend reading his book Refactoring: Improving the Design of Existing Code which discusses this refactoring technique as well as a host of others — to make it easier for creating future subclasses and to hopefully abate the chances of code duplication. That exercise gave birth to the following abstract class:

using System;

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

namespace Sitecore.Sandbox.Buckets.Ascertainers
{
    public abstract class BucketFolderPathAscertainer : IBucketFolderPathAscertainer
    {
        private string icon;
        protected string Icon
        {
            get
            {
                Assert.IsNotNullOrEmpty(icon, "Icon must be set in configuration!");
                return icon;
            }
            set
            {
                Assert.IsNotNullOrEmpty(value, "Icon must be set in configuration!");
                icon = value;
            }
        }

        private string toolTip;
        protected string ToolTip
        {
            get
            {
                Assert.IsNotNullOrEmpty(toolTip, "ToolTip must be set in configuration!");
                return toolTip;
            }
            set
            {
                Assert.IsNotNullOrEmpty(value, "ToolTip must be set in configuration!");
                toolTip = value;
            }
        }
        
        public virtual string GetIcon()
        {
            return Icon;
        }

        public virtual string GetToolTip()
        {
            return ToolTip;
        }

        public bool IsFolderPathMatch(BucketFolderPathAscertainerParameters parameters)
        {
            EnsureParameters(parameters);
            ID settingsItemID = GetSettingsItemID();
            Assert.IsTrue(!ID.IsNullOrEmpty(settingsItemID), "GetSettingsItemID() cannot return null or empty!");
            Item settingsItem = parameters.BucketItem.Database.GetItem(settingsItemID);
            Assert.IsNotNull(settingsItem, string.Format("Setting Item does not exist! Make sure it exists! Item ID: {0}", settingsItemID.ToString()));

            string resolvedPath = GetResolvedPath(parameters, settingsItem);
            if (string.IsNullOrWhiteSpace(resolvedPath))
            {
                return false;
            }

            return IsPathMatch(parameters, resolvedPath);
        }

        protected virtual void EnsureParameters(BucketFolderPathAscertainerParameters parameters)
        {
            Assert.ArgumentNotNull(parameters, "parameters");
            Assert.ArgumentNotNull(parameters.BucketItem, "parameters.BucketItem");
            Assert.ArgumentNotNull(parameters.BucketedItem, "parameters.BucketedItem");
            Assert.ArgumentCondition(parameters.BucketItem.Database == parameters.BucketedItem.Database, "parameters.BucketItem.Database", "parameters.BucketItem.Database and parameters.BucketedItem.Database must be the same database");
            Assert.ArgumentCondition(parameters.BucketItem.Axes.IsAncestorOf(parameters.BucketedItem), "parameters.BucketItem", string.Format("parameters.BucketItem", "Bucket Item: {0} must be an ancestor of Bucketed Item: {1}", parameters.BucketItem.ID.ToString(), parameters.BucketedItem.ID.ToString()));
            Assert.ArgumentNotNull(parameters.BucketedItem, "parameters.BucketedItem");
        }

        protected virtual ID GetSettingsItemID()
        {
            return Sitecore.Buckets.Util.Constants.SettingsItemId;
        }

        protected abstract string GetResolvedPath(BucketFolderPathAscertainerParameters parameters, Item settingsItem);

        protected virtual bool IsPathMatch(BucketFolderPathAscertainerParameters parameters, string resolvedPath)
        {
            if (string.IsNullOrWhiteSpace(resolvedPath))
            {
                return false;
            }

            string bucketedFolderPath = parameters.BucketedItem.Paths.ParentPath.Replace(parameters.BucketItem.Paths.FullPath, string.Empty);
            if(bucketedFolderPath.StartsWith("/"))
            {
                bucketedFolderPath = bucketedFolderPath.Substring(1);
            }

            return string.Equals(bucketedFolderPath, resolvedPath, StringComparison.OrdinalIgnoreCase);
        }
    }
}

The Icon and ToolTip property values in the above class live in the patch configuration file further down in this post. The Sitecore Configuration Factory will inject those values into these properties, and the GetIcon() and GetToolTip() will return the values housed in the Icon and ToolTip properties, respectively.

The IsFolderPathMatch() gets the settingsItem Item instance — this Item lives in /sitecore/system/Settings/Buckets/Item Buckets Settings in Sitecore — which is needed by the GetResolvedPath() method — this method is declared abstract and must be implemented by subclasses — whose job it is to get the bucketed Item’s folder path via the algorithm which the subclass implementation represents.

When the algorithm path is return, it is then passed to the IsPathMatch() method which determines if there is a match. If there is a match, true is returned to the caller of the IsFolderPathMatch() method; false is returned otherwise.

The class above combined with its subclasses would be an example of the Template method design pattern in action.

Now, we need a subclass of the above to determine if a bucketed Item’s path was generated by the Sitecore Rules Engine. Since we don’t want the Rules Engine to evaluate the rules defined on /sitecore/system/Settings/Buckets/Item Buckets Settings for the bucketed Item given the Item Bucket’s current state — its “when” Condition will most likely evaluate to false — we need a way to trick the Rules Engine. I came up with the following Condition class that always evaluates to true:

using Sitecore.Rules;
using Sitecore.Rules.Conditions;

namespace Sitecore.Sandbox.Rules
{
    public class AlwaysTrueWhenCondition<TRuleContext> : WhenCondition<TRuleContext> where TRuleContext : RuleContext
    {
        protected override bool Execute(TRuleContext ruleContext)
        {
            return true;
        }
    }
}

There isn’t much going on in the above class. Its Execute() method always returns true.

The following subclass of the BucketFolderPathAscertainer class determines if a bucketed Item’s path was generated by the Sitecore Rules Engine:

using System;
using System.Collections.Generic;

using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Buckets.Rules.Bucketing;
using Sitecore.Rules;
using Sitecore.Sandbox.Rules;

namespace Sitecore.Sandbox.Buckets.Ascertainers
{
    public class RulesDefinedBucketFolderPathAscertainer : BucketFolderPathAscertainer
    {
        protected override string GetResolvedPath(BucketFolderPathAscertainerParameters parameters, Item settingsItem)
        {
            string bucketRulesFieldId = GetBucketRulesFieldId();
            Assert.IsNotNullOrEmpty(bucketRulesFieldId, "GetBucketRulesFieldId() cannot return null or empty!");
            BucketingRuleContext ruleContext = CreateNewBucketingRuleContext(parameters);
            RuleList<BucketingRuleContext> rules = GetRuleList<BucketingRuleContext>(settingsItem, bucketRulesFieldId);
            SetAlwaysTrueWhenConditions(rules.Rules);
            if (rules == null)
            {
                return string.Empty;
            }

            try
            {
                rules.Run(ruleContext);
            }
            catch (Exception ex)
            {
                Log.Error(ToString(), ex, this);
            }

            return ruleContext.ResolvedPath;
        }

        protected virtual string GetBucketRulesFieldId()
        {
            return Sitecore.Buckets.Util.Constants.BucketRulesFieldId;
        }

        protected virtual BucketingRuleContext CreateNewBucketingRuleContext(BucketFolderPathAscertainerParameters parameters)
        {
            return new BucketingRuleContext(parameters.BucketedItem.Database, parameters.BucketItem.ID, parameters.BucketedItem.ID, parameters.BucketedItem.Name,
                            parameters.BucketedItem.TemplateID, parameters.CreationDateOfNewItem)
            {
                NewItemId = parameters.BucketedItem.ID,
                CreationDate = parameters.CreationDateOfNewItem
            };
        }

        protected virtual RuleList<T> GetRuleList<T>(Item settingsItem, string bucketRulesFieldId) where T : BucketingRuleContext
        {
            Assert.ArgumentNotNull(settingsItem, "settingsItem");
            Assert.ArgumentNotNullOrEmpty(bucketRulesFieldId, "bucketRulesFieldId");
            return RuleFactory.GetRules<T>(new[] { settingsItem }, bucketRulesFieldId);
        }

        protected virtual void SetAlwaysTrueWhenConditions<TRuleContext>(IEnumerable<Rule<TRuleContext>> rules) where TRuleContext : RuleContext
        {
            foreach(Rule<TRuleContext> rule in rules)
            {
                rule.Condition = CreateNewAlwaysTrueWhenCondition<TRuleContext>();
            }
        }

        protected virtual AlwaysTrueWhenCondition<TRuleContext> CreateNewAlwaysTrueWhenCondition<TRuleContext>() where TRuleContext : RuleContext
        {
            return new AlwaysTrueWhenCondition<TRuleContext>();
    }
    }
}

I’m not going to go too much into all the methods of this class given that most of the magic happens in the GetResolvedPath() method. It basically replaces all Conditions in the rules Sitecore.Rules.RulesList instance with an instance of the Condition class above; calls the Rules Engine API to evaluate the rules defined on the settingsItem instance though with the Conditions always returning true; and returns the resolved path to the caller.

The following class which also subclasses the BucketFolderPathAscertainer class — if I only had a dollar for every instance of the word “class” or “subclass” in this post — basically wraps an Sitecore.Buckets.Util.IDynamicBucketFolderPath instance — ahem, I mean employs the Adapter design pattern — where its GetResolvedPath() method delegates a call to the IDynamicBucketFolderPath instances GetFolderPath() method:

using Sitecore.Buckets.Util;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Buckets.Ascertainers
{
    public class DynamicBucketFolderPathPathAscertainer : BucketFolderPathAscertainer
    {
        private IDynamicBucketFolderPath PathResolver { get; set; }

        protected override string GetResolvedPath(BucketFolderPathAscertainerParameters parameters, Item settingsItem)
        {
            Assert.IsNotNull(PathResolver, "The IDynamicBucketFolderPath instance named PathResolver must be set in configuration!");
            return PathResolver.GetFolderPath(parameters.BucketItem.Database, parameters.BucketedItem.Name, parameters.BucketedItem.TemplateID,
                                                                parameters.BucketedItem.ID, parameters.BucketItem.ID, parameters.CreationDateOfNewItem);
        }
    }
}

You might be asking “what are we using the above class for?” Well, we are going to inject an instance of Sitecore.Buckets.Util.DateBasedFolderPath into the PathResolver property via the Sitecore Configuration Factory (please see the patch configuration file further down in this post).

I thought it might be cumbersome for a class to make calls to every single IBucketFolderPathAscertainer instance — sure, we only have two above but just think about how messy things will quickly progress if more are added. I decided I would utilize the Composite design pattern via the following class:

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

using Sitecore.Configuration;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Buckets.Ascertainers
{
    
    public class CompositeBucketFolderPathAscertainer : IBucketFolderPathAscertainer
    {
        private string Icon { get; set; }

        private string ToolTip { get; set; }

        private List<IBucketFolderPathAscertainer> FolderPathAscertainers { get; set; }

        public CompositeBucketFolderPathAscertainer()
        {
            FolderPathAscertainers = new List<IBucketFolderPathAscertainer>();
        }

        public string GetIcon()
        {
            return Icon;
        }

        protected virtual void SetIcon(string icon)
        {
            Assert.ArgumentNotNullOrEmpty(icon, "icon");
            Icon = icon;
        }

        public string GetToolTip()
        {
            return ToolTip;
        }

        protected virtual void SetToolTip(string toolTip)
        {
            Assert.ArgumentNotNullOrEmpty(toolTip, "toolTip");
            ToolTip = toolTip;
        }

        public bool IsFolderPathMatch(BucketFolderPathAscertainerParameters parameters)
        {
            if(FolderPathAscertainers == null || !FolderPathAscertainers.Any())
            {
                return false;
            }

            foreach(IBucketFolderPathAscertainer ascertainer in FolderPathAscertainers)
            {
                if(ascertainer.IsFolderPathMatch(parameters))
                {
                    SetIcon(ascertainer.GetIcon());
                    SetToolTip(ascertainer.GetToolTip());
                    return true;
                }
            }

            return false;
        }

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

            IBucketFolderPathAscertainer ascertainer = Factory.CreateObject(configNode, false) as IBucketFolderPathAscertainer;
            Assert.IsNotNull(ascertainer, "An IBucketFolderPathAscertainer was not defined correctly in configuration!");
            FolderPathAscertainers.Add(ascertainer);
        }
    }
}

All configuration-defined IBucketFolderPathAscertainer instances will be added to the FolderPathAscertainers List property via the AddFolderPathAscertainer() method (have a look at the configuration file below to see the AddFolderPathAscertainer() method being there for the Sitecore Configuration Factory to use).

The IsFolderPathMatch() method will then iterate over all IBucketFolderPathAscertainer instances and try to find a match. If a match is found, the instance of the class above will grab and save local copies of that IBucketFolderPathAscertainer instance’s Icon and Tooltip values, and then return true. If no match was found, it returns false.

Now, we need a way to grab one bucketed Item for an Item Bucket. I defined the following interface for a class whose instance will return one Item given another Item:

using Sitecore.Data.Items;

namespace Sitecore.Sandbox.Providers.Items
{
    public interface IItemProvider
    {
        Item GetItem(Item item);
    }
}

The following class implements the interface above:

using System;
using System.Linq;
using System.Linq.Expressions;

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.Sandbox.Providers.Items;

namespace Sitecore.Sandbox.Buckets.Providers.Items
{
    public class BucketedItemProvider : IItemProvider
    {
        private string BucketFolderTemplateId { get; set; }

        private string SearchIndexName { get; set; }

        private ISearchIndex searchIndex;
        private ISearchIndex SearchIndex
        {
            get
            {
                if (searchIndex == null && !string.IsNullOrWhiteSpace(SearchIndexName))
                {
                    searchIndex = GetSearchIndex(SearchIndexName);
                }

                return searchIndex;
            }
        }

        public virtual Item GetItem(Item bucketItem)
        {
            ID bucketFolderTemplateId;
            Assert.ArgumentCondition(ID.TryParse(BucketFolderTemplateId, out bucketFolderTemplateId), "BucketFolderTemplateId", "BucketFolderTemplateId cannot be empty and must be a Sitecore.Data.ID! Check its configuration setting!");
            Assert.ArgumentNotNull(bucketItem, "bucketItem");
            Assert.IsNotNullOrEmpty(SearchIndexName, "SearchIndexName is empty. Double-check its configuration setting!");
            Assert.IsNotNull(SearchIndex, "SearchIndex is null. Double-check the SearchIndexName configuration setting!");

            using (IProviderSearchContext searchContext = SearchIndex.CreateSearchContext())
            {
                var predicate = GetSearchPredicate<SearchResultItem>(bucketItem.ID, bucketFolderTemplateId);
                IQueryable<SearchResultItem> query = searchContext.GetQueryable<SearchResultItem>().Filter(predicate);
                SearchResults<SearchResultItem> results = query.GetResults();
                if (results.Count() < 1)
                {
                    return null;
                }

                SearchHit<SearchResultItem> hit = results.Hits.First();
                return hit.Document.GetItem();
            }
        }

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

        protected virtual Expression<Func<T, bool>> GetSearchPredicate<T>(ID bucketItemId, ID bucketFolderTemplateId) where T : SearchResultItem
        {
            var predicate = PredicateBuilder.True<T>();
            predicate = predicate.And(item => item.Paths.Contains(bucketItemId));
            predicate = predicate.And(item => item.TemplateId != bucketFolderTemplateId);
            predicate = predicate.And(item => item.Parent != bucketItemId);
            predicate = predicate.And(item => item.ItemId != bucketItemId);
            return predicate;
        }
    }
}

The class above is leveraging the Sitecore.ContentSearch API to get this bucketed Item.

Why am I using the Sitecore.ContentSearch API? Well, imagine if there are thousands if not tens of thousands of bucketed Items under the Item Bucket. A Sitecore query would be slow as molasses, and we need keep performance on our minds at all times for all of our solutions. Don’t lose sight of that on anything you build.

The GetSearchPredicate() method builds up and returns an Expression<Func> instance — let’s call this instance the “predicate”. The predicate basically says we want an Item who is a descendant of the Item Bucket; isn’t a Bucket Folder Item; lives under a Bucket Folder; and isn’t the Item Bucket Item.

The GetItem() method then uses that predicate and the Sitecore.ContentSearch API to gather those SearchResultItem instances, and then returns the Item instance on the first one in the result set if any were returned. If none were found, it returns null.

Since we have a lot of moving parts in this solution — just look at all of the classes you’ve just gone through — I need a way to piece all of this together for a GutterRenderer.

Unfortunately, we can’t magically inject instances into a GutterRenderer via the Sitecore Configuration Factory — well, you can call it but imagine all the calls I would need for this — so I decided to define the following interface whose classes would be used by a GutterRenderer, and these classes would be defined in Sitecore configuration:

using Sitecore.Data.Items;
using Sitecore.Shell.Applications.ContentEditor.Gutters;

namespace Sitecore.Sandbox.Shell.Applications.ContentEditor.Gutters
{
    public interface IGutter
    {
        GutterIconDescriptor GetIconDescriptor(Item item);

        bool IsVisible();
    }
}

The following class implements the interface above:

using System;

using Sitecore.Buckets.Extensions;
using Sitecore.Data.Fields;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Globalization;
using Sitecore.Shell.Applications.ContentEditor.Gutters;

using Sitecore.Sandbox.Buckets.Ascertainers;
using Sitecore.Sandbox.Determiners.Features;
using Sitecore.Sandbox.Providers.Items;
using Sitecore.Sandbox.Shell.Applications.ContentEditor.Gutters;

namespace Sitecore.Sandbox.Buckets.Gutters
{
    public class FolderPathBucketGutter : IGutter
    {
        private string DefaultIcon { get; set; }

        private string DefaultToolTip { get; set; }

        private string CreatedDatetimeFieldName { get; set; }

        private IFeatureDeterminer ItemBucketsFeatureDeterminer { get; set; }
        
        private IItemProvider BucketedItemProvider { get; set; }

        private IBucketFolderPathAscertainer FolderPathAscertainer { get; set; }

        public virtual GutterIconDescriptor GetIconDescriptor(Item item)
        {
            EnsureRequiredProperties();
            Assert.ArgumentNotNull(item, "item");

            if(!AreItemBucketsEnabled() || !item.IsABucket())
            {
                return null;
            }

            Item bucketedItem = GetBucketedItem(item);
            if(bucketedItem == null)
            {
                return CreateNewGutterIconDescriptor(DefaultIcon, DefaultToolTip);
            }

            BucketFolderPathAscertainerParameters parameters = new BucketFolderPathAscertainerParameters
            {
                BucketItem = item,
                BucketedItem = bucketedItem,
                CreationDateOfNewItem = GetItemCreatedDateTime(bucketedItem)
            };

            if(!FolderPathAscertainer.IsFolderPathMatch(parameters))
            {
                return CreateNewGutterIconDescriptor(DefaultIcon, DefaultToolTip);
            }

            return CreateNewGutterIconDescriptor(FolderPathAscertainer.GetIcon(), FolderPathAscertainer.GetToolTip());
        }

        protected virtual void EnsureRequiredProperties()
        {
            Assert.IsNotNull(FolderPathAscertainer, "FolderPathAscertainer must be defined in configuration!");
            Assert.IsNotNullOrEmpty(DefaultIcon, "DefaultIcon must be defined in configuration!");
            Assert.IsNotNullOrEmpty(DefaultToolTip, "DefaultToolTip must be defined in configuration!");
            Assert.IsNotNullOrEmpty(CreatedDatetimeFieldName, "CreatedDatetimeFieldName must be defined in configuration!");
        }

        public virtual bool IsVisible()
        {
            return AreItemBucketsEnabled();
        }

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

        protected virtual Item GetBucketedItem(Item bucketItem)
        {
            Assert.IsNotNull(BucketedItemProvider, "BucketedItemProvider must be set in configuration!");
            return BucketedItemProvider.GetItem(bucketItem);
        }

        protected virtual GutterIconDescriptor CreateNewGutterIconDescriptor(string icon, string toolTip)
        {
            Assert.ArgumentNotNullOrEmpty(icon, "icon");
            Assert.ArgumentNotNullOrEmpty(toolTip, "toolTip");
            return new GutterIconDescriptor
            {
                Icon = icon,
                Tooltip = TranslateText(toolTip)
            };
        }

        protected virtual string TranslateText(string text)
        {
            Assert.ArgumentNotNullOrEmpty(text, "text");
            return Translate.Text(text);
        }

        protected virtual DateTime GetItemCreatedDateTime(Item item)
        {
            Assert.IsNotNullOrEmpty(CreatedDatetimeFieldName, "CreatedDatetimeFieldName must be defined in configuration!");
            Assert.ArgumentNotNull(item, "item");
            DateField created = item.Fields[CreatedDatetimeFieldName];
            if(created == null)
            {
                return DateTime.MinValue;
            }

            return created.DateTime;
        }
    }
}

The AreItemBucketsEnabled() method in the above classes determines if the Item Bucket feature is enabled via the injected IBucketFolderPathAscertainer instance. This method is then used by the IsVisible() method which represents the method by the same name on GutterRenderer instances, and is also called by the GetIconDescriptor() method.

If the Item Buckets feature is not enabled, the GetIconDescriptor() method will return null as well as when the passed Item is not an Item Bucket.

If the passed Item is an Item Bucket, the GetIconDescriptor() gets one bucketed Item via the GetBucketedItem() method — this method just delegates to the IItemProvider instance injected into the class instance — and puts this bucketed Item as well as the Item Bucket into a BucketFolderPathAscertainerParameters parameters object instance. The creation date of the bucketed is also set on this parameters object since it is required when ascertaining whether the folder structure was constructed based on its creation date.

The BucketFolderPathAscertainerParameters instance is then passed to the IsFolderPathMatch() method on the injected IBucketFolderPathAscertainer property which determines if there is a folder path match.

If there is a match, a new GutterIconDescriptor instance is returned which contains the appropriate Icon and Tooltip.

If there is no match, then a new GutterIconDescriptor is returned with default values for the Icon and Tooltip.

This next class subclasses the GutterRenderer class:

using System;

using Sitecore.Configuration;
using Sitecore.Data.Items;
using Sitecore.Diagnostics;
using Sitecore.Shell.Applications.ContentEditor.Gutters;

namespace Sitecore.Sandbox.Shell.Applications.ContentEditor.Gutters
{
    public class ConfigDefinedGutterRenderer : GutterRenderer
    {
        private IGutter gutter;
        private IGutter Gutter
        {
            get
            {
                if (gutter == null)
                {
                    gutter = GetInnerGutterRenderer();
                }

                return gutter;
            }
        }

        protected override GutterIconDescriptor GetIconDescriptor(Item item)
        {
            Assert.IsNotNull(Gutter, "Gutter wasn't set properly. Double-check it!");
            return Gutter.GetIconDescriptor(item);
        }

        public override bool IsVisible()
        {
            Assert.IsNotNull(Gutter, "Gutter wasn't set properly. Double-check it!");
            return Gutter.IsVisible();
        }

        protected virtual IGutter GetInnerGutterRenderer()
        {
            string configPath = GetConfigPath();
            if (string.IsNullOrWhiteSpace(configPath))
            {
                Log.Error("ConfigDefinedGutterRenderer: configPath must be set as a parameter!", this);
                return null;
            }

            try
            {
                IGutter gutter = Factory.CreateObject(configPath, false) as IGutter;
                if (gutter == null)
                {
                    Log.Error(string.Format("ConfigDefinedGutterRenderer: the IGutter defined in {0} isn't correctly defined. Double-check it!", configPath), this);
                    return null;
                }

                return gutter;

            }
            catch (Exception ex)
            {
                Log.Error(ToString(), ex, this);
            }

            return null;
        }

        protected virtual string GetConfigPath()
        {
            string key = "configPath";
            if (Parameters.ContainsKey(key))
            {
                return Parameters[key];
            }

            return string.Empty;
        }
    }
}

The GetInnerGutterRenderer() method above calls the Sitecore Configuration Factory to grab an IGutter instance from a configuration path which is set on the Parameters field of the definition Item for this GutterRenderer in the Core database — see the screenshot further down in this post — when the Gutter property is called for the first time, and sets this instance on a private member on the class instance.

Both the GetIconDescriptor() and IsVisible() methods delegate to the methods on the IGutter instance with the same names (quiz time: what design pattern is this class using? 😉 ).

I then duct-taped everything together via the following patch configuration file:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <gutters>
      <folderPathBucketGutter type="Sitecore.Sandbox.Buckets.Gutters.FolderPathBucketGutter, Sitecore.Sandbox" singleInstance="true">
        <DefaultIcon>business/32x32/chest_add.png</DefaultIcon>
        <DefaultToolTip>This item is a bucket. You can use this as a content repository.</DefaultToolTip>
        <CreatedDatetimeFieldName>__Created</CreatedDatetimeFieldName>
        <ItemBucketsFeatureDeterminer ref="determiners/features/itemBucketsFeatureDeterminer" />
        <BucketedItemProvider ref="providers/items/bucketedItemProvider" />
        <FolderPathAscertainer ref="ascertainers/buckets/compositeBucketFolderPathAscertainer" />
      </folderPathBucketGutter>
    </gutters>
    <ascertainers>
      <buckets>
        <compositeBucketFolderPathAscertainer type="Sitecore.Sandbox.Buckets.Ascertainers.CompositeBucketFolderPathAscertainer, Sitecore.Sandbox" singleInstance="true">
          <ascertainers hint="raw:AddFolderPathAscertainer">
            <ascertainer ref="ascertainers/buckets/rulesDefinedBucketFolderPathAscertainer" />
            <ascertainer ref="ascertainers/buckets/dateBasedFolderPathAscertainer" />
          </ascertainers>
        </compositeBucketFolderPathAscertainer>
        <dateBasedFolderPathAscertainer type="Sitecore.Sandbox.Buckets.Ascertainers.DynamicBucketFolderPathPathAscertainer, Sitecore.Sandbox" singleInstance="true">
          <Icon>Business/32x32/calendar_down.png</Icon>
          <ToolTip>This item is a bucket. Its bucket folders were generated based on the creation date of the bucketed items. You can use this as a content repository.</ToolTip>
          <PathResolver type="Sitecore.Buckets.Util.DateBasedFolderPath, Sitecore.Buckets" />
        </dateBasedFolderPathAscertainer>
        <rulesDefinedBucketFolderPathAscertainer type="Sitecore.Sandbox.Buckets.Ascertainers.RulesDefinedBucketFolderPathAscertainer, Sitecore.Sandbox"
        singleInstance="true">
          <Icon>Business/32x32/briefcase_add.png</Icon>
          <ToolTip>This item is a bucket. Its bucket folders were generated by the rules engine. You can use this as a content repository.</ToolTip>
        </rulesDefinedBucketFolderPathAscertainer>
      </buckets>
    </ascertainers>
    <determiners>
      <features>
        <itemBucketsFeatureDeterminer type="Sitecore.Sandbox.Buckets.Determiners.Features.ItemBucketsFeatureDeterminer" singleInstance="true" />
      </features>
    </determiners>
    <providers>
      <items>
        <bucketedItemProvider type="Sitecore.Sandbox.Buckets.Providers.Items.BucketedItemProvider" singleInstance="true">
          <BucketFolderTemplateId>{ADB6CA4F-03EF-4F47-B9AC-9CE2BA53FF97}</BucketFolderTemplateId>
          <SearchIndexName>sitecore_master_index</SearchIndexName>
        </bucketedItemProvider>
      </items>
    </providers>
  </sitecore>
</configuration>

We need to let Sitecore know about the new Gutter addition. I did this in the Core database:

One thing to keep in mind is that the Sitecore Rules Engine folder path match will only work when we have an algorithm that will return the same path consistently for a bucketed Item. This unfortunately means I could not use the same Action from my previous post given that it generates random folder paths.

To over come this hurdle, I built the following Action which just reverses the bucketed Item’s ID (oh no, more code 😉 ):

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

using Sitecore.Buckets.Rules.Bucketing;
using Sitecore.Buckets.Rules.Bucketing.Actions;
using Sitecore.Diagnostics;

namespace Sitecore.Sandbox.Buckets.Rules.Actions
{
    public class CreateReversedIDBasedPath<TContext> : CreateIDBasedPath<TContext> where TContext : BucketingRuleContext
    {
        public override void Apply(TContext ruleContext)
        {
            Assert.ArgumentNotNull(ruleContext, "ruleContext");
            base.Apply(ruleContext);
            if (string.IsNullOrWhiteSpace(ruleContext.ResolvedPath))
            {
                return;
            }

            ruleContext.ResolvedPath = ReversePath(ruleContext.ResolvedPath);
        }

        protected virtual string ReversePath(string path)
        {
            if(string.IsNullOrWhiteSpace(path))
            {
                return string.Empty;
            }

            List<string> pieces = path.Split('/').ToList();
            pieces.Reverse();
            return string.Join("/", pieces);
        }
    }
}

I’m not going to go into details of how I set this in the rules on /sitecore/system/Settings/Buckets/Item Buckets Settings — you can see an example of how this is done from my previous post.

Now that everything is set, we can see that the new Gutter option is available:

I then turned it on:

As you can see, we have different Gutter icons for different folder structures.

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

Oh, by the way, if you made it all the way to the end of this post, then you deserve a treat. Go get yourself a cookie. You deserve it. 😉

Until next time, keep up the good fight, one piece of code at time. 😀