Allowed Renders of Sitecore Dynamic Placeholders

Question

I use Dynamic Placeholders in Sitecore 7 as described in the articles

• http://trueclarity.wordpress.com/2012/06/19/dynamic-placeholder-keys-in-sitecore/
• http://www.techphoria414.com/Blog/2011/August/Dynamic_Placeholder_Keys_Prototype

It works correctly, so I can add the same rendering to the layout and the rendering will go to the corresponding dynamic Placeholder. However, when I click to add rendering to a dynamic placeholder, placeholder settings are not used.

What I expect should be triggered by allowed visualizations that can be hosted on the Dynamic Placeholder. Instead, the render / layout tree is manually presented to select the rendered content editors to add forbidden visualizations to the placeholder.

I debugged the code, and the correct Placeholder parameter was found for the Dynamic Placeholder parameter, and the list of allowed Renderings is retrieved, despite the fact that it is set to args, the list is not presented to the user. See code below.

public class GetDynamicKeyAllowedRenderings : GetAllowedRenderings
{
    //string that ends in a GUID
    public const string DynamicKeyRegex = @"(.+){[\d\w]{8}\-([\d\w]{4}\-){3}[\d\w]{12}}";

    public new void Process(GetPlaceholderRenderingsArgs args)
    {
        Assert.IsNotNull(args, "args");

        // get the placeholder key
        string placeholderKey = args.PlaceholderKey;
        var regex = new Regex(DynamicKeyRegex);
        Match match = regex.Match(placeholderKey);

        // if the placeholder key text followed by a Guid
        if (match.Success && match.Groups.Count > 0)
        {
            // Is a dynamic placeholder
            placeholderKey = match.Groups[1].Value;
        }
        else
        {
            return;
        }

        Item placeholderItem = null;
        if (ID.IsNullOrEmpty(args.DeviceId))
        {
            placeholderItem = Client.Page.GetPlaceholderItem(placeholderKey, args.ContentDatabase,
                                                             args.LayoutDefinition);
        }
        else
        {
            using (new DeviceSwitcher(args.DeviceId, args.ContentDatabase))
            {
                placeholderItem = Client.Page.GetPlaceholderItem(placeholderKey, args.ContentDatabase,
                                                                 args.LayoutDefinition);
            }
        }

        // Retrieve the allowed renderings for the Placeholder
        List<Item> collection = null;
        if (placeholderItem != null)
        {
            bool allowedControlsSpecified;
            args.HasPlaceholderSettings = true;
            collection = this.GetRenderings(placeholderItem, out allowedControlsSpecified);
            if (allowedControlsSpecified)
            {
                args.CustomData["allowedControlsSpecified"] = true;
            }
        }
        if (collection != null)
        {
            if (args.PlaceholderRenderings == null)
            {
                args.PlaceholderRenderings = new List<Item>();
            }
            args.PlaceholderRenderings.AddRange(collection);
        }
    }
}

How this code was developed for Sitecore 6.5 / 6.6. I wonder if Sitecore 7.0 added a change to the second half of the code.

Answer 1

I found the source of the problem by decompiling the Sitecore 7 kernel and looking at the default GetAllowedRenderings class. If "Valid visualizations" are found, the ShowTree parameter must be set to false. See below

public class GetDynamicKeyAllowedRenderings : GetAllowedRenderings
    {
        //string that ends in a GUID
        public const string DynamicKeyRegex = @"(.+){[\d\w]{8}\-([\d\w]{4}\-){3}[\d\w]{12}}";

        public new void Process(GetPlaceholderRenderingsArgs args)
        {
            Assert.IsNotNull(args, "args");

            // get the placeholder key
            string placeholderKey = args.PlaceholderKey;
            var regex = new Regex(DynamicKeyRegex);
            Match match = regex.Match(placeholderKey);

            // if the placeholder key text followed by a Guid
            if (match.Success && match.Groups.Count > 0)
            {
                // Is a dynamic placeholder
                placeholderKey = match.Groups[1].Value;
            }
            else
            {
                return;
            }

            // Same as Sitecore.Pipelines.GetPlaceholderRenderings.GetAllowedRenderings from here but with fake placeholderKey
            // i.e. the placeholder without the Guid
            Item placeholderItem = null;
            if (ID.IsNullOrEmpty(args.DeviceId))
            {
                placeholderItem = Client.Page.GetPlaceholderItem(placeholderKey, args.ContentDatabase,
                                                                 args.LayoutDefinition);
            }
            else
            {
                using (new DeviceSwitcher(args.DeviceId, args.ContentDatabase))
                {
                    placeholderItem = Client.Page.GetPlaceholderItem(placeholderKey, args.ContentDatabase,
                                                                     args.LayoutDefinition);
                }
            }

            List<Item> collection = null;
            if (placeholderItem != null)
            {
                bool allowedControlsSpecified;
                args.HasPlaceholderSettings = true;
                collection = this.GetRenderings(placeholderItem, out allowedControlsSpecified);
                if (allowedControlsSpecified)
                {
                    // Hide the Layout/Rendering tree to show the Allowed Renderings
                    args.Options.ShowTree = false;
                }
            }
            if (collection != null)
            {
                if (args.PlaceholderRenderings == null)
                {
                    args.PlaceholderRenderings = new List<Item>();
                }
                args.PlaceholderRenderings.AddRange(collection);
            }
        }
    }

This change made by Sitecore 7 seems to be.