public function isValidFieldName(ViewableData $instance, $fieldName)
    {
        return ($instance->hasMethod($fieldName) || $instance->hasField($fieldName));
    }
public function isValidFieldName(ViewableData $instance, $fieldName)
    {
        return ($instance->hasMethod($fieldName) || $instance->hasField($fieldName));
    }
public function isValidFieldName ( ViewableData $ instance , $ fieldName ) { return ( $ instance -> hasMethod ( $ fieldName ) || $ instance -> hasField ( $ fieldName ) ) ; }
Returns true if the field name can be accessed on the given object

@param ViewableData $instance
@param string $fieldName
@return bool
Returns true if the field name can be accessed on the given object