Laravel Meetup Commands and Domain Events

Presentation For Laravel Meetup - Cape Town

Transcript

1. COMMANDS AND DOMAIN EVENTS
2. A LITTLE ABOUT ME Ron Darby • Developer At PayFast • JOINED 2013
3. A LITTLE ABOUT ME Family Man Asleep at Work
4. THE COMMAND WHY?? Encourages S.O.L.I.D principles Which Allows for: • Easy Maintenance • Easy to Extend • Clean Testable Code
5. COMMAND BUS Don’t ask, what is a Command Bus? It transports an Object from A to B • In Controller, Create Command ( Data Transfer Object ) • Pass the DTO into the Bus • The Bus is going to resolve the handler for that command using the IOC container • The CommandHandler will then delegate the DTO to a Model • The Model will then process the data and raise various Events • CommandHandler will then dispatch the Events and return Model to Controller The question should be, what does a Command Bus do?
6. COMMAND BUS Inside Command Bus? class CommandBus { public function execute( $command ) { $handler = str_replace( 'Command', 'CommandHandler', get_class( $command ) ); if( !class_exists( $handler ) ) { $message = "CommandHandler $handler does not exist"; throw new Exception( $message ); } return App::make( $handler )->handle( $command ); } } interface CommandHandler { public function handle($command); } Command Handler Interface
7. SOME CODE CONTROLLER class OrdersController extends BaseController { public function postPlace() { // Some Validation // Fetch cart items // Create an Order // Email Buyer and Seller // Redirect User for Payment } public function postItn() { // Some validation // Check if transaction duplicate, if not continue // Update the order status and create transaction // Email Buyer and Seller // Update Stock Levels } }
8. RESOURCES Laracasts: https://laracasts.com/series/com mands-and-domain-events Laravel Docs: http://laravel.com/docs/4.2 PayFast Docs: https://www.payfast.co.za/develo pers/
9. RON DARBY Twitter: https://twitter.com/smartydevelo per GitHub: https://github.com/RonDarby Email: ron.darby@payfast.co.za