Add getStartDate.

Calculate a new date, depending on the delay.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3439 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/SupplyLink.py

@@ -136,3 +136,16 @@ class SupplyLink(Path, XMLObject):
               if len(previous_ind_phase_list) == 0:
                 result = 1
       return result
+
+    security.declareProtected(Permissions.View, 'getStartDate')
+    def getStartDate(self, stop_date):
+      """
+        Calculate the start date, depending on the delay.
+      """
+      max_delay = self.getMaxDelay()
+      min_delay = self.getMinDelay()
+      for delay in [max_delay, min_delay, 0]:
+        if type(delay) in (type(1), type(1.0)):
+          start_date = stop_date - delay
+          break
+      return start_date