Bug 317595

Description Oleg Besedin 2010-06-22 10:55:26 EDT

The common pattern for use contexts with UI is:

- get a parent context
- create a local context parented of the parent context
- add some one-time use values in the local context
- #make() an object using the local context

The problem comes at the end of the life cycle: the local context is not stored and therefore we can't use #uninject(object, localContext). 

Possible solutions:

1) Add a variable to the object:
   @Inject IEclipseContext localContext;
and use it to dispose the local context, severing links between the parent context, local context, and the object

Pros: can be done with no changes to the framework 
Cons: a new field has to be added to every affected class

2) Keep a map of all contexts injected into the object and add a method

  static #getInjectedContext()

which would return the local context used in #make() and can be used to uninject

Cons: memory and performance impact - having a table and that lists all contexts and all injected objects and having to search through them on every context disposal scares me.

3) Create a new #make() / #inject() method that would take two contexts: dynamic and static, the parent context being used as dynamic and local context used as static. 
 localContext = EclipseContextFactory.create();
 object = ContextInjectionFactory.make(parentContext, localContext);

and then call #uninject(object, parentContext) as there will be no ties established to the local context.

Cons: it is RC1 and this will be a substantial change.

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I'll try (3) to see the impact of changes and if that turns out to be too much at this point, I'll do (2) for the initial release.