Allow to omit return in callback of Query Builder when()

[vlakoff]

I think laravel/framework#13091 should be reconsidered. Here is an example use case:

DB::from('foobar')
    ->when($exclude_ids, function ($qb) use ($exclude_ids) {
        return $qb->whereNotIn('id', (array) $exclude_ids);
    })
    ->inRandomOrder()
    ->limit($nb)
    ->get();

The "when" part isn't very sexy…, removing the return makes it a bit better:

DB::from('foobar')
    ->when($exclude_ids, function ($qb) use ($exclude_ids) {
        $qb->whereNotIn('id', (array) $exclude_ids);
    })
    ->inRandomOrder()
    ->limit($nb)
    ->get();

• The Query Builder instance is mutable, so it doesn't really make sense to return the instance.
• It is backward compatible, if you return anything else from the callback it will be used instead in the chain.
• The change in when() implementation is very simple.

[tomschlick]

return is consistent with the rest of the framework.

For instance query scopes: https://laravel.com/docs/5.3/eloquent#query-scopes

and almost every method on the collections: https://laravel.com/docs/5.3/collections#method-map

[vlakoff]

I think Collection methods are really a different case, where return is of course perfectly fine.

About scopes:

• The return is less bothering as it is inside simple methods, rather than a full query builder chain.
• In fact, the return in scopes apply()'s could (should) be omitted, as the return value is not used. See Builder::applyScopes() implementation, and the @return void phpdoc for apply().
• For dynamic scopes "scopeFoobar" there is a $this fallback similar to what I'm suggesting here. See in callScope() implementation: $result = call_user_func_array($scope, $parameters) ?: $this;

[vlakoff]

See also the code in this recent tweet: https://twitter.com/taylorotwell/status/784407839162851328

$validator = Validator::make(['name' => 'Taylor Otwell'], [
    'name' => [
        Rule::unique('users')->ignore(2)->using(function ($query) {
            $query->whereIn('foo', [1, 2, 3]);
        })
    ],
]);

edit: above new validation syntax has been implemented: laravel/framework#15809

[vlakoff]

Implemented in Laravel 5.4.16, by laravel/framework#18422.