General

  eZ Systems Website
  Editor documentation


  Developer documentation

  Back to the top

The documentation is moving!

We're moving our developer docs to Github and a new site.
The migration is still in progress, so please contact us in #documentation-contrib on eZ Community Slack if you have any questions or feedback.

This space will not be updated from now on except for critical fixes.

Skip to end of metadata
Go to start of metadata

Description

When you interact with the Public API, and with the content Repository in particular, Signals may be sent out, allowing you to react on actions triggered by the Repository. Those signals can be received by dedicated services called Slots.

To learn more about SignalSlot in eZ Platform, please refer to the dedicated documentation page.

Signals reference

This recipe will describe how to register a Slot for a dedicated Signal.

Solution

Registering a Slot for a given Signal

As described in the SignalSlot documentation, a Slot is roughly like an event listener and must extend eZ\Publish\Core\SignalSlot\Slot.

A typical implementation is the following:

OnPublishSlot

OnPublishSlot now needs to be registered as a service in the ServiceContainer and identified as a valid Slot:

services.yml (in your bundle)

Service tag ezpublish.api.slot identifies your service as a valid Slot. The signal part (mandatory) says that this slot is listening to ContentService\PublishVersionSignal (shortcut for \eZ\Publish\Core\SignalSlot\Signal\ContentService\PublishVersionSignal).

Internal signals emitted by Repository services are always relative to eZ\Publish\Core\SignalSlot\Signal namespace.

Hence ContentService\PublishVersionSignal means eZ\Publish\Core\SignalSlot\Signal\ContentService\PublishVersionSignal.

Tip

You can register a slot for any kind of signal by setting signal to * in the service tag.

Using a basic Symfony event listener

eZ Platform comes with a generic slot that converts signals (including ones defined by user code) to regular event objects and exposes them via the EventDispatcher. This makes it possible to implement a simple event listener/subscriber if you're more comfortable with this approach.

All you need to do is to implement an event listener or subscriber and register it.

Example

This very simple example will just log the received signal.

services.yml (in your bundle)

In this topic:

Related topics:

Events

Signal-Slot

Signals reference