Out Of Date Warning
This article was published on 23 Feb 2016, this means the content may be out of date or no longer relevant. You should verify that the technical information in this article is still current before relying upon it for your own purposes.
When I arrived at this topics I was a little bit confused about the difference between jobs and events, because they look very similar. Both of them help us to make our controllers very thin and easily understandable. So when should I choose an event and when it is appropriate for a job?
Let’s look at Laravel’s documentation: Laravel’s events provide a simple observer implementation, allowing you to subscribe and listen for events in your application. What does it mean?
Events usually describe things, that have occurred in the past. For example:
Events are picked up by listeners. When the event is fired all the listeners that are registered for that particular event are run and receive an event object with its data. The event system may be compared with the way how exceptions work. For example, you throw an exception, and you can define several catch blocks to react on it. In the case of events and listeners, an event is fired (thrown) and one or more listeners (catch blocks) react on it.
Events usually start and finish during the request lifecycle and cause something that needs to be handled.
An event could trigger a listener and register a job. For example, a UserRegistered event is fired, a listener picks up an event to send an email, and a job is queued.
A job is something that you want to happen (need to be done). For example:
Jobs are often tasks that work behind the scene (in the background). The may be executed during the request as a synchronous task or you can put them into a queue to respond the request as soon as possible. Then the queue handles the execution of all pending jobs (send an email, create a backup). They are executed according to the order they arrived or other scheduling requirements.
You may consider jobs as something that needs to be executed in order for your application to work properly. Events are mostly side effects/results of those actions - while important and useful, they play a secondary role.