er.extensions
Class ERXFrameworkPrincipal

java.lang.Object
  er.extensions.ERXFrameworkPrincipal

Direct Known Subclasses:

Ajax, BTBusinessLogic, ERAttachmentPrincipal, ERCaching, ERCoreBusinessLogic, ERDirectToWeb, ERIndexing, ERIUI, ERJavaMail, EROpenID, ERPlot, ERPrototypes, ERSelenium, ERTaggablePrincipal, ERXExtensions, GCGoogleChart, SproutCore

public abstract class ERXFrameworkPrincipal
extends Object

Designated starter class for frameworks, adds support for dependency management.
Allows you to disregard your framework order in the class path (at least where startup is concerned, if you override actual classes you still need to take care.)

The initialize() method will be called directly after your principal is instantiated.
The finishInitialization() method will be called when the app finishes startup but before it will begin to process requests.
If you define

public static Class[] REQUIRES = Class[] {...}

all the classes (which must be assignable from this class) will get loaded before your principal.
NOTE: try to avoid putting code in static initializers. These may lead to unpredictable behaviour when launching. Use one of the methods above to do what you need to do.

Here is an example:

 public class ExampleFrameworkPrincipal extends ERXFrameworkPrincipal {
 
     public static final Logger log = Logger.getLogger(ExampleFrameworkPrincipal.class);
 
     protected static ExampleFrameworkPrincipal sharedInstance;
     
     public final static Class REQUIRES[] = new Class[] {ERXExtensions.class, ERDirectToWeb.class, ERJavaMail.class};
 
     // Registers the class as the framework principal
     static {
         setUpFrameworkPrincipalClass(ExampleFrameworkPrincipal.class);
     }
 
     public static ExampleFrameworkPrincipal sharedInstance() {
         if (sharedInstance == null) {
             sharedInstance = (ExampleFrameworkPrincipal)sharedInstance(ExampleFrameworkPrincipal.class);
         }
         return sharedInstance;
     }
 
     public void initialize() {
         // code during startup
     }
 
     public void finishInitialization() {
         // Initialized shared data
     }
 }

Nested Class Summary

static class

ERXFrameworkPrincipal.Observer

Field Summary

protected Logger

log logging support

Constructor Summary

ERXFrameworkPrincipal()

Method Summary

abstract void	finishInitialization() Overridden by subclasses to provide framework initialization.
protected void	initialize() Called directly after the contructor.
static void	setUpFrameworkPrincipalClass(Class c) Sets up a given framework principal class to recieve notification when it is safe for the framework to be initialized.
static <T extends ERXFrameworkPrincipal> T	sharedInstance(Class<T> c) Gets the shared framework principal instance for a given class.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

log

protected final Logger log

logging support

Constructor Detail

ERXFrameworkPrincipal

public ERXFrameworkPrincipal()

Method Detail

sharedInstance

public static <T extends ERXFrameworkPrincipal> T sharedInstance(Class<T> c)

Gets the shared framework principal instance for a given class.

Parameters:

c - principal class for a given framework

Returns:

framework principal initializer

setUpFrameworkPrincipalClass

public static void setUpFrameworkPrincipalClass(Class c)

Sets up a given framework principal class to recieve notification when it is safe for the framework to be initialized.

Parameters:

c - principal class

initialize

protected void initialize()

Called directly after the contructor.

finishInitialization

public abstract void finishInitialization()

Overridden by subclasses to provide framework initialization.

toString

public String toString()

Overrides:

toString in class Object