Steve Alexander writes:

...

* Existence check: "_.hasattr(object,what)" NOTE, that this is the sloppy part.

- "_.hasattr" will return true, if "object" has attribute "what" (that is what we want) *OR* when it has acquired such an attribute (we do *NOT* want that here).

What we would need is a DTML accessible version of "aq_base". This is trivially handled by an external method.

Can you do this with the following in DTML?

<dtml-with "PARENTS[-1]" only> <dtml-if "_.hasattr(object, what)"> ...stuff... </dtml-if> </dtml-with> It may work for "PARENTS[-1]" but it can not be generalized:

The DTML namespace is essentially a stack of mappings. The "with" tag with the "only" attribute starts a new stack and pushes the object onto this new stack. Inside the "with", you will only see attributes of the object itself *or* attributes that the object acquired. This "or" is the problem. Acquisition and namespace stacking are orthogonal. You strip the namespace stacking with the "only" attribute (of the "with" tag), you strip the acquisition context with the "aq_base" attribute (of the object). Dieter