Inversion of Control in Crux
Page Contents:
The IoC (Inversion of control) container of Crux is the BeanProvider class. In the BeanProvider you typically define non-view classes that you want registered with the framework and available as injec
<?xml version="1.0" encoding="utf-8"?> <crux:BeanProvider xmlns:crux="library://ns.apache.org/royale/crux" xmlns:model="com.example.model.*" xmlns:control="com.example.control.*"> <model:ApplicationModel id="applicationModel"/> <control:UserController id="userController"/> </crux:BeanProvider>
Most applications define at least one Beans.mxml
in the root package and pass it to the Crux tag‘s beanProviders
property in the application’s main MXML file. For clarity and simplicity, it is recommended that you define your beans in a separate file, using BeanProvider as the root tag, as shown above. However, if for some reason you choose to define your beans inline in the Crux tag, you’ll need to wrap your objects with the Bean tag to ensure they are processed correctly:
<crux:Crux> <crux:beanProviders> <crux:BeanProvider> <crux:Bean name="applicationModel"> <model:ApplicationModel/> </crux:Bean> <crux:Bean name="userController"> <control:UserController/> </crux:Bean> </crux:BeanProvider> </crux:beanProviders> <crux:config> <crux:SwizConfig eventPackages="com.foo.events, org.bar.events" viewPackages="com.foo.views, org.bar.events"/> </crux:config> </crux:Crux>
Similar to Spring’s prototype scope{:target=‘_blank’}, Crux provides a Prototype
tag. Prototype
enables a few different things:
<crux:Prototype id="editViewPresoModel" type="{ EditViewPresentationModel }" constructorArguments="{ someOtherBean }" />
If you want deferred instantiation and/or constructor injection but not a unique copy for each injection you can set Prototype’s
singleton
property to true.
A Prototype bean created and injected into a view is not destroyed when the view is removed. Crux cannot know what else you may have done with the Prototype. If you wish to tear down a Prototype bean when a view is removed, implement a
[PreDestroy]
method and dispatch aTEAR_DOWN_BEAN
event for the Prototype bean.
Bean
property values can also be defined in external XML files. The CruxConfigValueLoader
Crux extension provides one way to handle this. For example, an XML file with this structure:
<config> <value1>This is value 1.</value1> <value2>This is value 2.</value2> </config>
Can be loaded and used in a BeanProvider by doing:
<externalconfig:CruxConfigValueLoader id="configLoader" source="config.xml" /> <controller:MyController id="myController" value1="{configLoader.configData.config.value1}" value2="{configLoader.configData.config.value2}" />
The CruxConfigValueLoader
can be injected just like any other bean:
[Inject] public var configLoader : CruxConfigValueLoader;
Finally, you can create an event handler to execute after the external data is loaded (remember to add “org.apache.royale.crux.externalconfig.event” to your eventPackages
):
[EventHandler( event = "ConfigLoaderEvent.CONFIG_LOAD_COMPLETE", properties = "configData" )] public function onConfigLoadComplete( configData : Object ) : void { // You can now reference the value with syntax such as: // configData.config.value1, configData.config.value2, etc. }