I have been looking back at Dev Diary Ep15 - Huge New Feature Revealed - Custom Elements!. Is there a write-up of the Elements API commands e.g. @each, @endeach etc and of the internal names available to be accessed. I haven’t been able to find any info in the docs yet (which I know isn’t complete). If there was a basic list (rather than full write-up) it would be useful.
Not yet… We can probably whip-up an example project if we know roughly what you’re trying to do. Let me know!
Here’s a project with a couple of custom components that have a few looping examples in 
Download Project.
Thanks for the project file. 
I was just wanting to try things out, so nothing specific at the moment.
I was trying an @if to see if that would work but can’t get the format correct.
Are all the @ commands executed in Elements prior to publishing, so that it doesn’t provide any sort of dynamic capability for which you would need to use PHP?