Request Life Cycle

In WP-FastEndpoints an endpoint can have multiple optional handlers attached to:

1. Permission handlers via hasCap(...) or permission(...) - Used to check for user permissions
2. Middlewares
   1. Request Payload Schema Middleware via schema(...) - Validates the request payload
   2. Response Schema Middleware via returns(...) - Makes sure that the proper response is sent to the client
   3. Custom middlewares via middleware(...) - Any other custom logic that you might want to run

Permission handlers

When a request is received the first handlers to run are the permissions handlers. Permission handlers are called by WordPress via permission_callback.

In contrast to WordPress, you can have one or multiple permission handlers attached to the same endpoint.

Note

In the background all permission handlers are wrapped into one callable which is later on used as permission_callback by the endpoint

These handlers will then be called in the same order as they were attached. For instance:

$router->get('/test', function () {return true;})
->hasCap('read')                # Called first
->hasCap('edit_posts')          # Called second if the first one was successful
->permission('__return_true')   # Called last if both the first and second were successful

Middlewares

If all the permission handlers are successful the next set of handlers that run are the middlewares which implement the onRequest function.

Remember that a middleware can implement onRequest and/or onResponse functions. The first one, runs before the main endpoint handler and the later one should run after the main endpoint handler.

Warning

Please bear in mind that if either a WP_Error or a WP_REST_Response is returned by the main endpoint handler following middlewares will not run. See Responses page for more info.

onRequest

Same as with the permission handlers, middlewares are called with the same order that they were attached.

class OnRequestMiddleware extends \Wp\FastEndpoints\Contracts\Middleware
{
    public function onRequest(/* Type what you need */){
        return;
    }
}

$router->post('/test', function () {return true;})
->middleware(OnRequestMiddleware()) # Called first
->schema('Basics/Bool');            # Called second

onResponse

Likewise, middlewares implementing onResponse functions will be triggered in the same order as they were attached.

class OnResponseMiddleware extends \Wp\FastEndpoints\Contracts\Middleware
{
    public function onResponse(/* Type what you need */){
        return;
    }
}

$router->post('/test', function () {return true;})
->returns('Basics/Bool')                # Called first
->middleware(OnResponseMiddleware());   # Called second