Hi, just wanted to follow this up with a last comment for people searching these boards trying to solve an issue like this.
I'd like to start by saying Jan was very patient, polite and as helpful as he could be - in short the support was excellent and speedy, the following complaint is aimed at the software only.
In the end this had to be abandoned - we had to deliver something slightly substandard to the client where they used the Rich Text Editor to place the full youtube embed iframe into the HTML - as opposed to the nice friendly functionality built into the CMS.
What Jan is saying is technically correct - the issue can be solved by using a repeater inside a repeater and using the OnItemDataBound event to hook up the internal loop.
However, the reason we had to abandon this was:
1) This is a horrendous way to have to build websites. Kentico's recompile time is awful so the last thing you want to have to do is to be tweaking changes inside the ascx page, recompiling and waiting a couple of minutes for the result each time. Anyone who has integrated complex modern HTML pages into any CMS would agree with this - the way you use the template language is the primary way you achieve efficiency in integrating the HTML cut.
2) Using repeaters in this way results in very unreadable / untransparent code where you have to start referencing the code behind to have any idea of what's going on - the very last thing you want inside a template!! This is the absolute opposite of the use of the simple inline for loops I wanted to use.
3) Repeaters are limited - no code forks
4) With reference to 3) the suggestion was to use things like
<%# Eval("aBoolValue") ? "some html" : "some other html" %>
With the complex HTML we were trying to output, while this would work it would leave more unreadable code which is very hard to debug / change in the future
There is a reason I went for using as much normal inline c# as possible on the aspx pages - no 5 minute re-compile times for small tweaks and clean readable HTML - both on the ASPX pages and the resulting HTML.
So I would argue that the issue wasn't "solved" - an unrealistic suggestion was put forwards instead.
My suggestion to the dev team would be to extract the functionality which processes things like the youtube tags to enable this processing to happen outside of a specific control - I see no reason to limit the ability to call this functionality to just that method of calling it.