[Zope] Name Error / Global name not defined

[J. Cameron Cooper]

>The python script looks like:
>
># Creates a pending array
>
>pendingArray = ['test']
>return pendingArray
>
>and is called by this line in the DTML document.
><dtml-call expr="createPendingArray()">
>
>The line that is causing the error to be thrown is:
>
><dtml-call
>expr="addEntryPendingArray(pendingArray,Word)">
>which causes the following error:
>	
>Error Type: NameError
>Error Value: global name 'pendingArray' is not defined
>  
>
There's a suitable answer out there, but I thought I'd get a little 
deeper on this.

Your Python script isn't executed in the namespace of the DTML document. 
Which is to say, 'pendingArray' is local--visible only to the script 
during its execution--and disappears from the universe as soon as the 
script finshes. Only the result is available to the caller: the DTML 
method, and if nothing is done with it, it goes poof.

If you want the result of that script (a list) available in the DTML, 
you have to put it in the DTML namespace somehow, which is what the 
dtml-let solution did. You could also use the result like::

<dtml-call expr="addEntryPendingArray(createPendingArray(),Word)">

Here the result of 'createPendingArray' is available to the 
'addEntryPendingArray' method as an argument. After that method 
completes, the result (the value of the list originally assigned to 
'pendingArray') is again lost to the ether.

          --jcc
-- 

"My point and period will be throughly wrought,
Or well or ill, as this day's battle's fought."