[Checkins] SVN: z3c.pt/trunk/src/z3c/pt/expressions.py Provide useful error message if provider is not found (similar to the TALES expression in zope.contentprovider).

[Malthe Borch]

Log message for revision 91137:
  Provide useful error message if provider is not found (similar to the TALES expression in zope.contentprovider).

Changed:
  U   z3c.pt/trunk/src/z3c/pt/expressions.py

-=-
Modified: z3c.pt/trunk/src/z3c/pt/expressions.py
===================================================================
--- z3c.pt/trunk/src/z3c/pt/expressions.py	2008-09-14 10:12:35 UTC (rev 91136)
+++ z3c.pt/trunk/src/z3c/pt/expressions.py	2008-09-14 15:34:11 UTC (rev 91137)
@@ -3,6 +3,7 @@
 
 from zope.traversing.adapters import traversePathElement
 from zope.contentprovider.interfaces import IContentProvider
+from zope.contentprovider.interfaces import ContentProviderLookupError
 
 import parser
 import re
@@ -751,8 +752,13 @@
 path_translation = PathTranslation()
 
 def get_content_provider(context, request, view, name):
-    cp = zope.component.getMultiAdapter(
+    cp = zope.component.queryMultiAdapter(
         (context, request, view), IContentProvider, name=name)
+
+    # provide a useful error message, if the provider was not found.
+    if cp is None:
+        raise ContentProviderLookupError(name)
+
     cp.update()
     return cp.render()