function getRequiredAttrs()
    {
        $required = array();
        foreach ($this->requested_attributes as $type_uri => $attribute) {
            if ($attribute->required) {
                $required[] = $type_uri;
            }
        }

        return $required;
    }
function getRequiredAttrs()
    {
        $required = array();
        foreach ($this->requested_attributes as $type_uri => $attribute) {
            if ($attribute->required) {
                $required[] = $type_uri;
            }
        }

        return $required;
    }
function getRequiredAttrs ( ) { $ required = array ( ) ; foreach ( $ this -> requested_attributes as $ type_uri => $ attribute ) { if ( $ attribute -> required ) { $ required [ ] = $ type_uri ; } } return $ required ; }
Get the type URIs for all attributes that have been marked as
required.

@return array A list of the type URIs for attributes that have been
marked as required.
Get the type URIs for all attributes that have been marked as required .