[Zope] <dtml-var> namespace resolution monitoring?

[Dylan Reinhardt]

At 02:48 PM 2/8/2003, Derek Basch wrote:
>Can anyone suggest some strategies for determining
>where a <dtml-var> is resolving its value from?

First off, are you certain that this mystery variable isn't some "magic" 
method provided by Zope?  You may want to post the name of the variable 
just to be sure.  Assuming that this isn't the case, it can only be coming 
from four places:

1. It's part of your REQUEST object.
2. It's an object contained by the folder your script is in or any of that 
folder's parents.
3. It's provided by some object referenced in your URL
4. It's provided by some object you're traversing in the script or are 
otherwise putting into the namespace

There are several things you can do to narrow this down, including:

  - Comment out all of the script except for that <dtml-var>... is the 
value still resolved?
  - Put a method of the same name in the same folder... is that method's 
value used instead?  If so, keep moving the method up the hierarchy until 
the effect disappears.
  - If you using a URL that differs from the "physical" path of the object, 
take a close look at any objects included in the URL.
  - If commenting everything but the <dtml-var> breaks the variable, pay 
particular attention to any objects referenced by <dtml-with>, <dtml-in> 
and (un)restrictedTraverse.  Your mysterious name provider probably lurks 
within.

After you've figured out this mess, you should strongly consider re-writing 
with Python Scripts.  DTML should never be used for anything complicated 
enough to defy easy inspection... but I'll spare you the lecture since you 
didn't write it. :-)

HTH,

Dylan