[Zope] Extending <!--#var fmt=...-->

[Michel Pelletier]

> -----Original Message-----
> From: Alexander Staubo [mailto:alex@mop.no]
> Sent: Thursday, July 22, 1999 1:01 PM
> To: Zope Mailing List (E-mail)
> Subject: [Zope] Extending <!--#var fmt=...-->
> 
> 
> I asked this before, but I don't recall getting any responses.
> 
> It seems that you can write
> 
>   <!--#var SomeVariable fmt=SomeMethod-->
> 
> and SomeMethod -- assuming it is, for example, an External Method --
> will be called. Unfortunately it seems SomeMethod is not 
> called with any
> parameters -- meaning it cannot access the variable or value to be
> rendered.
> 

Actually the intended behavior is to be:

<!--#var someObject fmt=someMethodofSomeObject-->

So the method called is supposed to be a method of 'someObject',
however, due to the beauty of acquisition, an unitended result is that
if someObject is wrapped, it will acquire a method if it doesn't have
one and one is acquirable.  This is why your external method gets
called.

The intention of having no parameters was that because the method is of
the object you want to render, it can simply get any any values it needs
using it's self reference.  This is how DatTime objects work, which is
you can:

<!--#var dateTimeInstance fmt=day-->

Which will call 'dateTimeInstance.day()'.  I think, I'm not sure, but I
think that if you pass 'self' into your external method as it's first
argument, it should bind the method to the object in question.  I'm not
sure though.

Of course, if you want to modify the behavior of fmt to support some
kind of expression syntax, your more than welcome to.  We will evaluate
the patch and include it.

-Michel

> Is this by design? Is there any way of extending fmt= by 
> having it call
> our methods with the value as a parameter? I've successfully 
> patched the
> appropriate source code to verify that it is indeed possible 
> to do what
> I'm looking for, so... why not? Security reasons?
> 
> -- 
> Alexander Staubo             http://www.mop.no/~alex/
> "`Ford, you're turning into a penguin. Stop it.'"
> --Douglas Adams, _The Hitchhiker's Guide to the Galaxy_
> 
> _______________________________________________
> Zope maillist  -  Zope@zope.org
> http://www.zope.org/mailman/listinfo/zope
> 
> (To receive general Zope announcements, see:
> http://www.zope.org/mailman/listinfo/zope-announce
> 
> For developer-specific issues, zope-dev@zope.org -
> http://www.zope.org/mailman/listinfo/zope-dev )
>