[Zope] stopping acquisition

[Dieter Maurer]

Dan Keshet writes:
 > ...
 > <dtml-with aq_explicit>
 > <dtml-if method_y>
 > Yup
 > <dtml-else>
 > Nope
 > </dtml-if>
 > </dtml-with>
 > 
 > But it says "Yup" in Folders without a method_y
"aq_explicit" is not fail safe.

If you know that your objects are always folders, you
can use that folders provide access to their content via
subscription and use the following Python Script:

	 hasChild(folder,id):
	   try: folder[id]; return 1
	   except KeyError: return 0

If your objects are arbitrary, you should use an external
method:

	hasOwnAttribute(object,attr):
	  o= getattr(object,'aq_base',object)
	  return hasattr(o,attr)

Of course, you can make a HotFix product (--> HowTo on Zope.org)
to provide such a beast as "TemplateDict" attribute
(I think, Zope should have such a method builtin).


Dieter