Kentico Web Part Zone(s) generated by Transformations

Question

I am using a Repeater web part in Kentico to pick out pages from the content tree, to generate nicely repeatable snippets of structured HTML, based on an ASCX transformation. (No surprises here - its been working great!).

However, a new requirement landed whereby alongside the existing HTML structure mentioned above, each repeated item must also have an area where we can add any amount of additional content; based on other web parts.

I have previously written a few "layout" type web parts; implementing CMSAbstractLayoutWebPart, as described here, which has allowed me to generate a repeating amount of web part zones, so I feel like I'm half way there. The issue with that though is that as it stands, I don't seem to be able to make use of the great power and flexibility of the transformations on the page type (which I really think I need to do, and seems like it should be possible..).

I thought I may be able to specify the WebPartZone control in the transformation markup directly, like in the following:

<%@ Register Src="~/CMSInlineControls/WebPartZone.ascx" TagName="CMSWebPartZone" TagPrefix="cms" %>
<cms:CMSWebPartZone ZoneID="ZoneIDHere" runat="server" />
<div>
  <h3><%# Eval("Heading") %></h3>
  <p><%# Eval("Summary") %></p>
</div>

But the design view doesn't seem to pick up the web part zone; so I'm assuming the page lifecycle may not allow me to do this as I'd hoped.

So what I would like to know is:

1. Is it possible to include WebPartZone control in a transformation such that I can then bring in new web parts in Design view?
2. If not, what is the recommended way to go about this? (If a custom web part is the way to go, I'd like to clone the Repeater web part in the first instance, as many of its existing properties will be needed - but presumably this must still inherit from CMSAbstractLayoutWebPart?

Thanks!

Update

Good point about the editor's experience; I would definitely like to keep this as consistent as possible. The issue for me is that the requirements that drive my data structures are not always fully understood - and are certainly subject to change. Also, they are liable to vary (albeit subtly) across different products. So I've been trying to keep templates and page types more or less the same across the board, and push out the differences into page properties that drive web part config through macros. So given that the transformation approach won't work, I expect a custom web part is the right fit for me.

I shall post my findings!

Answer 1

In the end, I was able to use transformation markup to specify the generation of web part zones. I went down the route of creating a custom web part that inherits from CMSAbstractLayoutWebPart, rather than using CMSRepeater web part or similar...

Here's a breakdown of things I needed to do this:

• Gave the custom layout-type web part some properties with which to query the content tree, and supply them to a TreeProvider.SelectNodes() method in the web part code once it has initialised (by overriding the OnInit() method)
• Gave the web part a TransformationName property so that the raw markup can be retrieved using TransformationInfoProvider.GetTransformation(this.TransformationName)
• Used the markup above and resolved macros within it using each node from the node query

Example of macro resolution code (HTML transformations with macros)

protected virtual string ResolveNode(TreeNode node)
{
    var resolver = this.ContextResolver.CreateChild();
    resolver.AddAnonymousSourceData(node);
    return resolver.ResolveMacros(rawTransformationMarkup);
}

• Then I go looking for placeholder text in the transformation markup and use the methods available in the CMSAbstractLayoutWebPart parent class(es), as detailed here, to Append() the resolved markup and also call AddZone() as necessary to tap into the response string builder

Summary: The great functionality of the API allowed me to completely avoid the use of any repeater controls. I could generate web part zones as part of the layout web part usual layout generation process.

It would be nice if I could figure out how to resolve the expressions in SCRIPT tags in ASCX transformations to complete the story, but by using HTML transformations I can use the above to accomplish what I need.

Answer 2

I think adding a web part zone into transformation is not a right direction as web part zone should be a part of page template (not transformation) in order to utilize it.

I'd probably try to organize my content so each item you currently showing in the repeater has any number of child pages (potentially of a different type) and use something like hierarchical viewer in order to present all of them on the page. It allows using different transformation based on either page type or node level. Another advantage of this approach is that you keep editors experience consistent.