Index: openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl,v
diff -u -r1.320.2.15 -r1.320.2.16
--- openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl	27 May 2014 07:33:51 -0000	1.320.2.15
+++ openacs-4/packages/xowiki/tcl/xowiki-www-procs.tcl	25 Jul 2014 19:07:52 -0000	1.320.2.16
@@ -1807,6 +1807,21 @@
     return 1
   }
 
+  Page ad_instproc validate=form_input_fields {form_fields} {
+    #
+    # This is the form-level validator, which might be used to perform
+    # validation based on e.g. multiple depending formfields.  The
+    # validator can be used to test inter-dependencies between
+    # form-fields and should set the error fields of the reporting
+    # form field(s) via
+    #
+    #   $f error_msg "some error...."
+    #
+    # This method can be refined by e.g. a workflow.
+    #
+    return 1
+  }
+
   Page ad_instproc get_form_data {-field_names form_fields} {
 
     Get the values from the form and store it in the form fields and
@@ -1964,6 +1979,10 @@
       set validation_errors [my mutual_overwrite_occurred]
     }
 
+    if {[my validate=from_input_fields $form_fields]} {
+      incr validation_errors
+    }
+
     if {$validation_errors == 0} {
       #
       # Postprocess based on form fields based on form-fields methods.