Lifecycle

Fairy's container will manage the lifecycle of the components, and it will be responsible for creating and destroying the components.

Launching

Here is few graph about how lifecycle works in a fairy plugin.

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Plugin Lifecycle

Life Cycle	Description
Plugin.onLoad()	The alternative of JavaPlugin.onLoad()
Plugin.onPreEnable()	The alternative of JavaPlugin.onEnable(), called before anything is initialized.
Launch Fairy Container	Initializing the container of the main fairy package. see Container Lifecycle.
Launch Plugin Container	Initializing the container of the plugin package, see Container Lifecycle.
Plugin.onPostEnable()	Called after everything is initialized.

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Container Lifecycle

Life Cycle	Description
Scan Through Packages	Class Scanner will scan through the specified package and cache them for launching.
Resolve Dependency Graph	Resolve dependencies depends on the way they are injected, see Dependencies.
Provide Instances	Provide instances for every object (injectable components) if they are singleton. if an object was prototype they won't be created by default unless they are dependent by other singleton.
Change Object state to PRE_INIT	The pre initialize state of the container, autowired fields will be injected and life cycle callback methods are called.
Handle Object Collector	Object collector active, every objects will be put into collectors and adds them depends on their condition.
Change Object state to POST_INIT	The post initialize state of the container, @Subscribe methods will be registered and life cycle callback methods are called.

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Callbacks

Fairy container provides a few callback methods that can be used to perform some actions when the container is initializing or destroying.

@PreInitialize Annotation

The @PreInitialize annotation is used to mark a method as a pre-initialize method. The method will be called before the object is fully initialized. (aka PRE_INIT state.)

@InjectableComponent
public class MyComponent {
    @PreInitialize
    public void onPreInitialize() {
        // ...
    }
}

@PostInitialize Annotation

The @PostInitialize annotation is used to mark a method as a post-initialize method. The method will be called after the object is fully initialized. (aka POST_INIT state.)

@InjectableComponent
public class MyComponent {
    @PostInitialize
    public void onPostInitialize() {
        // ...
    }
}

@PreDestroy Annotation

The @PreDestroy annotation is used to mark a method as a pre-destroy method. The method will be called before the object is destroyed. (aka PRE_DESTROY state.)

@InjectableComponent
public class MyComponent {
    @PreDestroy
    public void onPreDestroy() {
        // ...
    }
}

@PostDestroy Annotation

The @PostDestroy annotation is used to mark a method as a post-destroy method. The method will be called after the object is destroyed. (aka POST_DESTROY state.)

@InjectableComponent
public class MyComponent {
    @PostDestroy
    public void onPostDestroy() {
        // ...
    }
}

JSR-250 Annotations

Fairy also supports the JSR-250 annotations for lifecycle callbacks. The @PostConstruct and @PreDestroy annotations can be used to mark methods as post-initialize and pre-destroy methods.

@InjectableComponent
public class MyComponent {
    @PostConstruct
    public void onPostConstruct() {
        // ...
    }
    
    @PreDestroy
    public void onPreDestroy() {
        // ...
    }
}