Laravel Collections “when” Method

Starting at v5.4.12, Laravel Collections now includes a when method that allows you to perform conditional actions on the items without breaking the chain.

Like all the other Laravel Collection methods this one can have a lot of use cases but one example that comes to mind is being able to filter based on a query string parameter.

To demonstrate that example, let’s pretend we have a list of hosts from the Laravel News Podcast:

1$hosts = [
2    ['name' => 'Eric Barnes', 'location' => 'USA', 'is_active' => 0],
3    ['name' => 'Jack Fruh', 'location' => 'USA', 'is_active' => 0],
4    ['name' => 'Jacob Bennett', 'location' => 'USA', 'is_active' => 1],
5    ['name' => 'Michael Dyrynda', 'location' => 'AU', 'is_active' => 1],
6];

Previously to filter based on a query string you might do something like this:

1$inUsa = collect($hosts)->where('location', 'USA');
2
3if (request('retired')) {
4    $inUsa = $inUsa->filter(function($employee){
5        return ! $employee['is_active'];
6    });
7}

With the new when method you can now do this all in one Collection chain:

1$inUsa = collect($hosts)
2    ->where('location', 'USA')
3    ->when(request('retired'), function($collection) {
4        return $collection->reject(function($employee){
5            return $employee['is_active'];
6        });
7    });