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<h1><img src="../../intro/css/images/ecf_intro.gif">Eclipse Communication Framework (ECF)</h1>
<p>
<h2>ISharedObject Lifecycle - DRAFT</h2>
<h4>ISharedObject Construction</h4>
A SharedObject can be instantiated two ways:
<ol>
<li>By invoking one of the 'createSharedObject' methods of an
ISharedObjectContainer. These methods require a SharedObjectDescription
parameter (which among other things defines the class of object to
instantiate).
</li>
<li>By calling the constructor of an object class which implements
the ISharedObject interface outside of any container.
</li>
</ol>
<h4>Initialization</h4>
After it has been constructed the container to
which it was added will invoke the ISharedObject.init method passing a
non-null ISharedObjectConfig. ISharedObjects created outside of a
container, will have their ISharedObject.init method invoked
immediately as part of being added to the container.
<br>
Although not required, a typical implementation of 'init' will
cache the ISharedObjectConfig for later usage by the ISharedObject:
<br>
<pre> public void init(ISharedObjectConfig config) throws<br> SharedObjectInitException {<br> this.config = config;<br> ...<br> }<br></pre>
<b>Note</b>: The ISharedObjectConfig parameter provides the
ISharedObject with access to it's
container-provided context (<a
href="http://www.eclipse.org/ecf/org.eclipse.ecf.docs/api/org/eclipse/ecf/core/ISharedObjectContext.html">ISharedObjectContext</a>)
via a call to ISharedObjectConfig.getContext().
The ISharedObject is not considered initialized until after the init
method is completed, and
therefore the ISharedObjectContext is not available until after the
init method returns.
<br>
<br>
After init completes successfully, containers are required to
immediately deliver an 'activated' event to the newly added
ISharedObject via
ISharedObject.handleEvent(SharedObjectActivatedEvent).
<h4>Relationship to its container</h4>
ISharedObjects can be created outside of a ISharedObjectContainer and
then later added to it using the
ISharedObjectContainer.getSharedObjectManager().addSharedObject()
method.
<br>
<br>
The only semantics that an ISharedObjectContainer requires of
ISharedObjects is that they implement the ISharedObject interface.
<h4>Communications</h4>
<h5>Sending Messages</h5>
Eclipse ECF provides the ISharedObject with a simple asynchronous
messaging API to send/receive
arbitrary messages via the container-provided <a
href="http://www.eclipse.org/ecf/org.eclipse.ecf.docs/api/org/eclipse/ecf/core/ISharedObjectContext.html">ISharedObjectContext</a>.
On the
ISharedObjectContext, are methods to send arbitrary messages to remotes
(sendMessage). For details see
the methods on <a
href="http://www.eclipse.org/ecf/org.eclipse.ecf.docs/api/org/eclipse/ecf/core/ISharedObjectContext.html">ISharedObjectContext</a>.
<br>
<h5>Receiving Events</h5>
Containers can asynchronously deliver messages to SharedObjects in the
form of Events. When a message is received
for a given ISharedObject, the enclosing container wraps that message
in the form of an event of a certain type,
and calls that ISharedObject's handleEvent method with the Event
instance.
<h4>ISharedObject removal from a container</h4>
When an ISharedObject is removed from a container (or removes itself),
it's enclosing container calls the
ISharedObject.dispose() method.
<h4>Example Creation Code</h4>
Here is a code snippet that creates a container and adds a single
shared object to that container:
<pre>ISharedObjectContainer container = SharedObjectContainerFactory.getDefault().createSharedObjectContainer('standalone');<br>ID newID = IDFactory.createStringID('foo');<br>SharedObjectDescription sd = new SharedObjectDescription(newID,TestSharedObject.class);<br>container.getSharedObjectManager().createSharedObject(sd,null);<br></pre>
Note this creates and adds to the container a ISharedObject instance of
class "TestSharedObject". The TestSharedObject
null constructor is called, followed by a call to
ISharedObject.init(ISharedObjectConfig) by the enclosing container.
The container also sends an 'activated' event to the ISharedObject by
calling its handleEvent method with
an event of type
org.eclipse.ecf.core.events.SharedObjectActivatedEvent.
<br>
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