[Zope-dev] Why is TemplateDict so opaque? -and- Have youseen this problem?

[Dave Parker]

"Phillip J. Eby" wrote:
> Try this:
> 
> <!--#var standard_html_header-->
> Depth: <dtml-var "methodA(_.None,_,counter=counter+1)">
> <!--#var standard_html_footer-->

Andrew Duncan suggested this one as well more or less as well - thanks.
BUT! (read on...)

> Horrible workarounds?  Not really. Just make sure that if you're going to
> call any kind of DTML-ish thing with parameters, the first two positional
> parameters should be _.None and _ so that the current namespace is passed
> through.

Well, yes they were horrible; minus knowing that to descend more than
two levels deep in evaluated method calls I must start passing these
things, the workarounds *are* extremely ugly.  So I'm glad I have this
tidbit in my head now, but I've made a *lot* of compromises since :(

And I continue to maintain that this is a *BUG* - here's why:

(slightly modified version of the original example - emphasises bug
issue)


This version blows up:
methodA:
	Depth: <dtml-var counter>
	<dtml-if "counter < 2">
	<dtml-var "methodA(counter=counter+1)">

The error:

Error type:  KeyError
Error value: counter

This one works fine:
methodA:
	Depth: <dtml-var counter>
	<dtml-if "counter < 1">
	<dtml-var "methodA(counter=counter+1)">

Output is:

Depth: 0 Depth: 1


I strongly believe this is a bug in that if it's the case that my
namespace goes away minus passing in the namespace as a parameter, the
second example *should not have worked*.  It strikes me that someone
went to the effort to ensure that namespace gets passed down for me to
*some* extent, becuase I'm getting "Depth: 1".  That it should fail at
the next level appears entirely arbitrary.

If this is really really not a bug, then we are going to have a piece of
documentation that says:

"If you want to call your methods within an expression context where
you're calling depth is greater than two, you must pass in the namespace
as (_.None,_[,...])"

I would personally be embarassed to have such a note in there.

Sorry, but this one has frustrated me way too many times. Please tell me
why I'm wrong.


Thanks,

Dave Parker