[Bese-devel] How to use tal-templates

[astor at pvv.ntnu.no]

On Mon, Aug 15, 2005 at 03:25:38PM +0200, Marco Baringer wrote:
> 
> currenlty we don't have a way for a nested componnet to affect the
> tags generated by the window component, nor do we have an already
> existing mechanism which would allow this.
> 
> would it be worth the effort to make simple-window-component (or
> something) walk the component tree before the render-on phase and
> collect extra head headers (like script or even meta or link)?
> 

I think so.  But just to complete the picture, I can think of the
following use-cases:

o Sometimes you want to place supporting javascript in HEAD.  This is
  the proper way to ensure that they are available.  Putting the script
  in BODY could often be buggy since the code might not be available
  when an event fires in the javascript world.

o Sometimes a component might want to place supporting javascript in
  HEAD _once_ even if the component is rendered multiple times.
  (maybe a property-like interface would be good for this stuff).

o Maybe a component would like to produce an "external"
  .js-file for that particular component and refer to that .js-file
  _once_ in HEAD if the component is being used.  This could be a good
  solution for complex components (AJAX maybe).

o Sometimes you want to put javascript in BODY, but AFAIK, that will
  typically not be code that simply defines functions, but rather code
  that does stuff, like your alert example.  But this is supported
  rather well already I think.

So to me it seems like a component might want to produce:
o Global code (external .js-file)
o Per request, "per instance" code in HEAD.
o Per request, "per instance" code in BODY.
o Per request, "per class" code in HEAD.

astor