getQuantityPrecisionFromResource ignores empty strings, so that you can safely

call doc.getQuantityPrecisionFromResource(doc.getResource()) even if resource
is not set on doc.



git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@12351 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/Base.py

@@ -2541,9 +2541,11 @@ class Base( CopyContainer,
   def getQuantityPrecisionFromResource(self, resource):
     """
       Provides a quick access to precision without accessing the resource
-      value in ZODB
+      value in ZODB. Here resource is the relative_url of the resource, such as
+      the result of self.getResource(). 
     """
     def cached_getQuantityPrecisionFromResource(resource):
+      if resource:
         resource_value = self.portal_categories.resolveCategory(resource)
         if resource_value is not None:
           return resource_value.getQuantityPrecision()