+ protected static function boot()
+ {
+ parent::boot();
+
+ // Load book slugs onto these models by default during query-time
+ static::addGlobalScope('book_slug', function (Builder $builder) {
+ $builder->addSelect(['book_slug' => function ($builder) {
+ $builder->select('slug')
+ ->from('books')
+ ->whereColumn('books.id', '=', 'book_id');
+ }]);
+ });
+ }