The Module Manager¶
The module manager, Zend\ModuleManager\ModuleManager
, is a very simple class which is responsible for iterating
over an array of module names and triggering a sequence of events for each. Instantiation of module classes,
initialization tasks, and configuration are all performed by attached event listeners.
Module Manager Events¶
Events triggered by Zend\ModuleManager\ModuleManager
- loadModules
- This event is primarily used internally to help encapsulate the work of loading modules in event listeners, and allow the loadModules.post event to be more user-friendly. Internal listeners will attach to this event with a negative priority instead of loadModules.post so that users can safely assume things like config merging have been done once loadModules.post is triggered, without having to worry about priorities at all.
- loadModule.resolve
Triggered for each module that is to be loaded. The listener(s) to this event are responsible for taking a module name and resolving it to an instance of some class. The default module resolver shipped with ZF2 simply looks for the class
{modulename}\Module
, instantiating and returning it if it exists.The name of the module may be retrieved by listeners using the
getModuleName()
method of theEvent
object; a listener should then take that name and resolve it to an object instance representing the given module. Multiple listeners can be attached to this event, and the module manager will trigger them in order of their priority until one returns an object. This allows you to attach additional listeners which have alternative methods of resolving modules from a given module name.- loadModule
- Once a module resolver listener has resolved the module name to an object, the module manager then triggers this event, passing the newly created object to all listeners.
- loadModules.post
- This event is triggered by the module manager to allow any listeners to perform work after every module has
finished loading. For example, the default configuration listener,
Zend\ModuleManager\Listener\ConfigListener
(covered later), attaches to this event to merge additional user-supplied configuration which is meant to override the default supplied configurations of installed modules.
Module Manager Listeners¶
By default, Zend Framework provides several useful module manager listeners.
Provided Module Manager Listeners
- ZendModuleManagerListenerDefaultListenerAggregate
- To help simplify the most common use case of the module manager, ZF2 provides this default aggregate listener. In most cases, this will be the only listener you will need to attach to use the module manager, as it will take care of properly attaching the requisite listeners (those listed below) for the module system to function properly.
- ZendModuleManagerListenerAutoloaderListener
- This listener checks each module to see if it has implemented
Zend\ModuleManager\Feature\AutoloaderProviderInterface
or simply defined thegetAutoloaderConfig()
method. If so, it calls thegetAutoloaderConfig()
method on the module class and passes the returned array toZend\Loader\AutoloaderFactory
. - ZendModuleManagerListenerConfigListener
- If a module class has a
getConfig()
method, this listener will call it and merge the returned array (orTraversable
object) into the main application configuration. - ZendModuleManagerListenerInitTrigger
- If a module class either implements
Zend\ModuleManager\Feature\InitProviderInterface
, or simply defines aninit()
method, this listener will callinit()
and pass the current instance ofZend\ModuleManager\ModuleManager
as the sole parameter. Theinit()
method is called for every module implementing this feature, on every page request and should only be used for performing lightweight tasks such as registering event listeners. - ZendModuleManagerListenerLocatorRegistrationListener
- If a module class implements
Zend\ModuleManager\Feature\LocatorRegisteredInterface
, this listener will inject the module class instance into theServiceManager
using the module class name as the service name. This allows you to later retrieve the module class from theServiceManager
. - ZendModuleManagerListenerModuleResolverListener
- This is the default module resolver. It attaches to the “loadModule.resolve” event and simply returns an
instance of
{moduleName}\Module
. - ZendModuleManagerListenerOnBootstrapListener
If a module class implements
Zend\ModuleManager\Feature\BootstrapListenerInterface
, or simply defines anonBootstrap()
method, this listener will register theonBootstrap()
method with theZend\Mvc\Application
bootstrap
event. This method will then be triggered during thebootstrap
event (and passed anMvcEvent
instance).Like the
InitTrigger
, theonBootstrap()
method is called for every module implementing this feature, on every page request, and should only be used for performing lightweight tasks such as registering event listeners.- ZendModuleManagerListenerServiceListener
If a module class implements
Zend\ModuleManager\Feature\ServiceProviderInterface
, or simply defines angetServiceConfig()
method, this listener will call that method and aggregate the return values for use in configuring theServiceManager
.The
getServiceConfig()
method may return either an array of configuration compatible withZend\ServiceManager\Config
, an instance of that class, or the string name of a class that extends it. Values are merged and aggregated on completion, and then merged with any configuration from theConfigListener
falling under theservice_manager
key. For more information, see theServiceManager
documentation.Unlike the other listeners, this listener is not managed by the
DefaultListenerAggregate
; instead, it is created and instantiated within theZend\Mvc\Service\ModuleManagerFactory
, where it is injected with the currentServiceManager
instance before being registered with theModuleManager
events.