Simple use-case: you want to filter only those categories which have at least one product. Or course, you write Category::with('products')->... but how do you filter out those empty categories? Those with no product? There's an app function for that: has().
Let's show the full code.
app\Category.php:
class Category extends Model {
// ...
public function products() {
return $this->hasMany('App\Product');
}
// ...
}
app\Http\Controller\CategoriesController.php:
function getIndex() {
$categories = Category::with('products')->has('products')->get();
return view('categories.index', compact('categories'));
}
So, as you can see, it's a simple filter-function ->has('products') - it will filter out the categories without products.
