[Zope] stopping indexing of acquired attributes

[Luca Olivetti]

Chris Withers wrote:
> Luca Olivetti wrote:
> 
>> I stumbled into another problem: the method is useable for indexes but 
>> not for metadata.
>> I digged into the source of ZCatalog and I saw that's because Zcatalog 
>> first calls recordify (see Catalog.py) on the object which uses MV 
>> (from Missing) to indicate a missing attribute, while each plugin 
>> index uses a different method to identify a missing attribute (for 
>> example, UnIndex.py defines an internal _merker as []).
> 
> 
> Why would hypothesise that the real problem is that adding stuff to 
> indexes ignores AttributeError's and KeyError's which storing it as 
> metadata doesn't, which it should.

Yes, this is the quick fix I finally adopted:

--- Catalog.py.orig     Tue Dec 31 10:25:44 2002
+++ Catalog.py  Tue Dec 31 10:39:28 2002
@@ -400,8 +400,11 @@
          record = []
          # the unique id is allways the first element
          for x in self.names:
-            attr=getattr(object, x, MV)
-            if(attr is not MV and callable(attr)): attr=attr()
+            try:
+                attr=getattr(object, x, MV)
+                if(attr is not MV and callable(attr)): attr=attr()
+            except AttributeError:
+                attr=MV
              record.append(attr)
          return tuple(record)


> 
>> So if my method uses
>>
>>    attr=getattr(context.aq_explicit,'myattribute')
>>
>> it will tipically work in a plugin index because it's wrapped in a try 
>> except block, but will not work with metadata since there's no 
>> try/except there.
> 
> 
> So put one in yourself ;-) (well, something that works the same...)
> 
> attr=getattr(context.aq_explicit,'myattribute',None)


That was the first thing I tried but it didn't (aesthetically) please 
me: *all* object would be catalogged (it not the same None than the 
missing value each plugin index and metadata uses).

Bye

-- 
Luca Olivetti
Wetron Automatización S.A. http://www.wetron.es/
Tel. +34 93 5883004      Fax +34 93 5883007