Added an API to create a default price calculation context to computer price.

product/ERP5/Document/Resource.py

@@ -645,6 +645,16 @@ class Resource(XMLObject, XMLMatrix, VariatedMixin):
         return -1 # a defines a destination section and wins
       return 1 # a defines no destination section and loses
 
+
+    def _getPriceCalculationContext(self):
+      # Tries to find a default context to feed the price calculation
+      # process. For example, it will set a context in which the
+      # destination_section is set to the end user the the currency
+      # to the preferred currency of the end user
+      method = self._getTypeBasedMethod('getPriceCalculationDefaultContext')
+      if method is not None:
+        return method()
+
     security.declareProtected(Permissions.AccessContentsInformation,
                               'getPriceParameterDict')
     def getPriceParameterDict(self, context=None, REQUEST=None,
@@ -747,6 +757,8 @@ class Resource(XMLObject, XMLMatrix, VariatedMixin):
       """
       Return the unit price of a resource in a specific context.
       """
+      if context is None:
+        context=self.Resource_getPriceCalculationDefaultContext()
       # see Movement.getPrice
       if isinstance(default, Base) and context is None:
         msg = 'getPrice first argument is supposed to be the default value'\