+ #run when adding
+ 'new_callback' => sub { my( $cgi, $object, $fields_listref, $opt_hashref ) = @_; },
+
+ #run when editing
+ 'edit_callback' => sub { my( $cgi, $object, $fields_listref, $opt_hashref ) = @_; },
+
+ #run when re-displaying with an error
+ 'error_callback' => sub { my( $cgi, $object, $fields_listref, $opt_hashref ) = @_; },
+
+ #run when cloning
+ 'clone_callback' => sub { my( $cgi, $object, $fields_listref, $opt_hashref ) = @_; },
+
+ ###callbacks called in new mode only
+
+ # returns a hashref for the new object
+ 'new_hashref_callback'
+
+ # returns the new object iself (otherwise, ->new is called)
+ 'new_object_callback'
+
+ ###display callbacks
+
+ #run before display to return a different value
+ 'value_callback' => sub { my( $columname, $value ) = @_; },
+
+ #run before display to manipulate element of the 'fields' arrayref
+ 'field_callback' => sub { my( $cgi, $object, $field_hashref ) = @_; },
+
+ &>