Dependency Injection Container
Last updated Dec 10th, 2021 | Page history | Improve this page | Report an issue
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Learn moreMODX 3 introduces a Dependency Injection Container, based on Pimple 3, that holds core services and custom services.
The container is available in modX:$services
, meaning it is typically accessible in one of the following ways:
-
$modx->services
(in snippets, plugins, etc) -
$this->modx->services
(in controllers, processors, etc) -
$this->xpdo->services
(in model classes)
Available Services¶
At this time, the following services are automatically registered in the core:
-
config
: returns an array of configuration properties.
Loading Services¶
To load a service from the container, call the get
method (and/or has()
method to first check if it exists) with the ID for the service.
try {
$config = $modx->services->get('config');
}
catch (ContainerExceptionInterface $e) {
// handle the thing not being available
}
Or:
$service = null;
try {
if ($modx->services->has('custom_service')) {
$service = $modx->services->get('custom_service');
}
}
catch (ContainerExceptionInterface $e) {
// handle the thing not being available
}
A service existing (i.e.
has()
returning true) is not a guarantee that it wont cause an exception whenget()
is called for it.
Injecting Services¶
The recommended way to inject or overwrite services in an extension is through a namespace's bootstrap.php file, which runs as early in the initialisation process as possible.
For example, you may call:
$modx->services->add('my_service', function($c) use ($modx) {
return new MyPackage\MyService($modx);
});
You can use proper dependency injection by passing in the required services. Hypothetical example:
$modx->services->add('my_service', function($c) use ($modx) {
return new MyPackage\MyService($c['sessions'], $c['parser']);
});
If you require a new instance to be returned for each service request, use the factory()
method:
$modx->services['my_service'] = $modx->services->factory(function($c) use ($modx) {
return new MyPackage\MyService($modx);
});
To extend a previously defined service, use extend:
$modx->services->extend('existing_service', function($existing, $c) use ($modx) {
$existing->...();
return $existing;
});
See the Pimple documentation for more information.
Support the team building MODX with a monthly donation.
The budget raised through OpenCollective is transparent, including payouts, and any contributor can apply to be paid for their work on MODX.
Backers
Budget
$311 per month—let's make that $500!
Learn more