Welcome , Registration , and other StartingPoints ; TWiki history & Wiki style; All the docs.. ... Base class of all field definition classes. ... populateMetaDataFromQuery( $query, $meta, $old ) -> ($bValid, $bPresent) . ... Construct a list of the CSS classes for the form field. ... Try and get a sensible default value for the field from the values stored in the form definition. ... Return $bValid true if the value in $meta was updated (either from the query or from a default in the form. ...