Add a new method getGroupCriterion.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@909 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/InvoiceCell.py

@@ -149,3 +149,9 @@ Une ligne tarifaire."""
       # Never divergent
       return 0
 
+    security.declareProtected(Permissions.AccessContentsInformation, 'getGroupCriterion')
+    def getGroupCriterion(self):
+      """
+        Return the criterion for grouping. This should be overriden by each class.
+      """
+      return self.getPrice()

product/ERP5/Document/InvoiceLine.py

@@ -159,3 +159,9 @@ Une ligne tarifaire."""
       # Never divergent
       return 0
 
+    security.declareProtected(Permissions.AccessContentsInformation, 'getGroupCriterion')
+    def getGroupCriterion(self):
+      """
+        Return the criterion for grouping. This should be overriden by each class.
+      """
+      return self.getPrice()