From 862b358254bc248b1632a7363d8072a1806bf27b Mon Sep 17 00:00:00 2001
From: Helmut Merz <helmutm@cy55.de>
Date: Fri, 28 Oct 2011 13:02:50 +0200
Subject: [PATCH] provide method for controlling which macro from which
 template will be used for rendering

---
 composer/schema/field.py      | 3 +++
 composer/schema/interfaces.py | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/composer/schema/field.py b/composer/schema/field.py
index 7f88b11..2e1f63e 100644
--- a/composer/schema/field.py
+++ b/composer/schema/field.py
@@ -199,6 +199,9 @@ class FieldInstance(object):
         self.errors.append(error)
         self.severity = max(error.severity, self.severity)
 
+    def getRenderer(self, name):
+        return None
+
 
 class NumberFieldInstance(FieldInstance):
 
diff --git a/composer/schema/interfaces.py b/composer/schema/interfaces.py
index 6ed3551..8429aa3 100644
--- a/composer/schema/interfaces.py
+++ b/composer/schema/interfaces.py
@@ -278,6 +278,14 @@ class IFieldInstance(Interface):
             allow for checking more than one data element.
         """
 
+    def getRenderer(name):
+        """ Return the renderer object (e.g. a ZPT macro) for this field
+            with the name given.
+
+            May return None in which case the calling application should
+            use a default renderer.
+        """
+
 
 class IFormState(Interface):
     """ Represents the state of all fields when editing.