[10.x] Wrap response preparation in events

[timacdonald]

This enables user-land implementations of #45603 without actually bringing the feature to the framework.

For example:

public function boot(): void
{
    $logQueries = false;

    Event::listen(PreparingResponse::class, function () use (&$logQueries) {
        $logQueries = true;
    });

    Event::listen(ResponsePrepared::class, function () use (&$logQueries) {
        $logQueries = false;
    });

    DB::listen(function (QueryExecuted $event) use (&$logQueries) {
        if ($logQueries) {
            // log in production, throw locally.
        }
    });
}

[decadence]

@timacdonald PreparingResponse and ResponsePrepared are dispatched twice for simple view return. Is this by design or I missing something?

public function index()
{
    return view("index", [
        "title" => "Main Page"
    ]);
}

[decadence]

Yes. Because prepareResponse runs twice (don't know why it's needed).

[timacdonald]

The events will fire whenever a response is being "prepared". If the normal flow hits that method twice it will fire twice.

I also don't know why it does it twice, however at a quick glance it looks like it might be required so that responses returned via middleware are correctly "prepared".

[decadence]

Ok, thanks. It runs for view preparation and before final response (after "after" middlewares).