Introduce _cacheable_key to custom cache entries per field type

  This is required by Listbox for example in order to cache per list_start.

product/ERP5Form/ListBox.py

@@ -31,7 +31,7 @@ from OFS.Traversable import NotFound
 from AccessControl import ClassSecurityInfo, Unauthorized
 from Products.Formulator.DummyField import fields
 from Products.Formulator import Widget, Validator
-from Products.Formulator.Field import ZMIField
+from Products.Formulator.Field import Field, ZMIField
 from Products.Formulator.Errors import FormValidationError, ValidationError
 from Selection import Selection, DomainSelection
 from Tool.SelectionTool import createFolderMixInPageSelectionMethod
@@ -2954,6 +2954,17 @@ class ListBox(ZMIField):
     else:
       return ZMIField.get_value(self, id, **kw)
 
+  
+  def _cacheable_key(self):
+    selection_tool = self.getPortalObject().portal_selections
+    selection_name = self.get_value('selection_name')
+    selection = selection_tool.getSelectionFor(selection_name, REQUEST =self.REQUEST)
+    if selection is not None:
+      key = ("list_start", selection.getParams().get("list_start"))
+      return key
+      
+    return "default"
+
   security.declareProtected('Access contents information', 'getListMethodName')
   def getListMethodName(self):
     """Return the name of the list method. If not defined, return None.

product/ERP5Form/ProxyField.py

@@ -761,6 +761,15 @@ class ProxyField(ZMIField):
     if proxy_field is not None:
       return proxy_field.get_value(id, **kw)
 
+  def _cacheable_key(self):
+    selection_name = self.get_value('selection_name')
+    if selection_name is not None:
+      selection_tool = self.getPortalObject().portal_selections
+      selection = selection_tool.getSelectionFor(selection_name, REQUEST = self.REQUEST)
+      if selection is not None:
+        return ("list_start", selection.getParams().get("list_start"))
+    return "default"
+
   def _getCacheId(self):
     return '%s%s' % ('ProxyField', self._p_oid or repr(self))
 

product/Formulator/Field.py

@@ -491,6 +491,9 @@ class ZMIField(
         """The title of this field."""
         return self.get_value('title')
 
+    def _cacheable_key(self):
+      return "default"
+
     # display edit screen as main management screen
     security.declareProtected('View management screens', 'manage_main')
     manage_main = DTMLFile('dtml/fieldEdit', globals())
@@ -721,7 +724,8 @@ class ZMIField(
         keyset = {'here': self,
                   'value': value, 
                   'render_prefix' : render_prefix, 
-                  'key_prefix': key_prefix}
+                  'key_prefix': key_prefix, 
+                  'widget_keyset': self._cacheable_key()}
         LOG("ZMIField.render_htmlgrid", 0, keyset)
         result = self.ZCacheable_get(keywords=keyset)
         if result is not None: