[Twisted-web] Alternative to <nevow:attr>

[Andrew Bennetts]

On Tue, Oct 19, 2004 at 12:42:46AM -0700, David Reid wrote:
[...]
> Which is horrendously ugly and difficult to explain to pretty much
> anyone.  Now, there are plenty of other solutions to this problem, but
> none of them provide the flexability for the template author as
> <nevow:attr> and <nevow:slot> do.
> 
> For instance:
>    <nevow:attr name="href">
>         /users/<nevow:slot name="username" />/images
>    </ nevow:attr>
> 
> Works perfectly well.  Which according to fzZzy is the main reason for
> choosing this syntax.
> 
> A comparison to this with the syntax of TAL was recently mentioned on
> the ML (Comparison with ZPT [Was: [Twisted-web] Sub-tag level templating
> in Nevow: possible?]), and the TAL syntax seems to be cleaner, though
> I'm not sure if it provides the above functionality.  While discussing

TAL does allow this, in two ways (that I know of):

First, there's the hackish way:

    <a tal:attributes="href python:'/users/' + context/username + '/images'"
     />

The second way is to put this sort of complex code a view:

    class ViewBlah:
        def __init__(self, context, request):
            self.context = context
            self.request = request
        def imagesPath(self):
            return '/users/' + self.context.username + '/images'
    
then you can do:

    <a tal:attributes="href view/imagesPath" />

-Andrew.