- Page->content_header_append/content_header_get: new methods to include HTML content before the form. One use case ist to include additional forms this way, since these cannot be included in the main form of a FormPage. The additional content is displayed in the www-view method.
- FormPage->create_form_fields_from_names: new convenience function to create form-fields via their names. The definitions of the named form-fields are taken from the provided form_constraints. This function is useful when only a subset of the form-constraints definitions should be used to create form-fields.
- improve comments
- improve argument checking on parent_id to be able to provide better error messages