[Zope] A ZPT newbie question

[Clemens Robbenhaar]

Hi Wankyu Choi,
 > Hi all,
 > 
 > There must be a better way than:
 > 
 >     <span tal:omit-tag="" tal:condition="python: this_object is not
 > None">
 >         <span tal:replace="python: this_object.getSomethingBig() " />
 >     </span>
 > 

 "tal:condition" is evaluated before "tal:replace" (see Zope Book,
Appendix C, ZPT Reference), thus You should be able to save at least one
<span> by saying:

 <span tal:condition="python: this_object is not None"
       tal:replace="python: this_object.getSomethingBig() " /> 

    
 > The following gives an attribute error if 'this_object' is None:
 > 
 >     <span tal:replace="python: test(this_object is not None,
 > this_object.getSomethingBig(), '')" />
 >         
 > test() seems to always evaluate both params no matter what. 
 [...]

 Yes, "test" is a "normal" function, and no magic syntax; arguments are
always evaluated before the function "test" is evaluated.

Cheers,
Clemens