Messenger! Queue work for Later

Hey ElGovanni

Yes, that's a good use case. Writing a big file is another good example

Cheers!

it's useful for any tasks that are heavy

Like sending e-mail by symfony mailer?

We use Swarrot Bundle (it's similar to Symfony messenger) to do tasks asynchronously without blocking a request.

Example: user did some actions on the site. We dispatch event using Symfony Dispatcher which sends message to RabbitMQ. Then processor receives message from a queue and sends notification to Slack.

This allows us reduce server response time, resend notification if it fails, etc.

Hey @ElGovanni!

I think, even if you don’t have any heavy work, Messenger enables this “command bus design pattern”. If you love that pattern, it’s awesome. If you don’t care so much, then yea, there’s much less use for it. So, it’s useful for any tasks that are heavy OR if you just want to leverage the command bus pattern.

Cheers!

Cool feature but after 14 episodes I don't have in mind any use case for messenger.

Hey skyCatalysm,

Thank you for your interest in this screencast, your vote is counted. We do plan to record it some day, but unfortunately, we don't have any estimations yet - too many good stuff we would like to work on before it.

Thank you for your patience!

Cheers!

Awesome series and perfect timing for me as well! I have a big project coming up that will utilize the Messenger component.

Hi! will symfony cast ever tackle about mercure bundle? and when?

I get what your saying and it makes sense. I was going to swallow the whole dragon and test from the message dispatch to the results of the handlers work in one test.

Thank again for your time. It's always appreciated.

Hey Skylar Scotlynn Gutman!

I don't think that specific topic will make it into this tutorial, so I'll give you some tips here :). The main reason is that (delightfully) there is nothing special about unit testing a handler. If you think about it, a handler is no different than any other service you might build in your app - it's a service, it uses dependency injection and it has a public method that "does" something. The only difference is that the method is called __invoke, which means that when you're calling it in your test, instead of $myService->myMethod('fooArg') it will be $myService('fooArg') (you execute the object like a function).

The one other interesting thing about a handler is that they (unless you're using messenger as a query bus... but, different topic) never return anything. That's not a strict requirement - messenger doesn't care if you do - but you typically don't, because Messenger doesn't care about your return value (and neither should you when you dispatch to Messenger). This means that your unit tests will typically be testing what a handler function *does* instead of what it returns - e.g. you might test that it calls flush() on the entity manager. If you find that there are some other things internally that you'd like to test but are having trouble (for example, you want to test that an entity was created and with the correct data... before being saved), it's probably a sign that you should refactor that small piece you want to test into its own service, test that, then autowire the new service into your handler.

Let me know if this helps! If i missed the heart of your question, definitely tell me ;).

Cheers!

Hello guys,

Thank you for this tutorial.

I was wondering if you could help me write a unit test for the message handler. How would you go about it? May be you could add a chapter on the topic.

wow, I would love to watch this!!!!

I've been waiting for this course for a long time.
Great job.