protected function determineModelReferenceSource(Model $model)
    {
        $source = $this->getReferenceSource($model);

        // If we have no source to fall back on at all, use the model key
        if ( ! $source) {
            $source = $model->getKeyName();
        }

        return $source;
    }
protected function determineModelReferenceSource(Model $model)
    {
        $source = $this->getReferenceSource($model);

        // If we have no source to fall back on at all, use the model key
        if ( ! $source) {
            $source = $model->getKeyName();
        }

        return $source;
    }
protected function determineModelReferenceSource ( Model $ model ) { $ source = $ this -> getReferenceSource ( $ model ) ; // If we have no source to fall back on at all, use the model key if ( ! $ source ) { $ source = $ model -> getKeyName ( ) ; } return $ source ; }
Returns the reference source string.

@param Model $model
@return null|string
Returns the reference source string .