Example on how to use IContextFunction in Eclipse 4

Question

I read about org.eclipse.e4.core.contexts.IContextFunction but could not find online an actual example.
My understanding is that a component implements an IContextFunction and on calling compute another object is lazily created.
But how/when the compute method is called it is not clear to me.
For example with the following:

<?xml version="1.0" encoding="UTF-8"?>  
<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0"   
  name="com.example.e4.rcp.todo.contextservice.translate">  

<implementation class="com.example.e4.rcp.todo.contextservice.Test"/>  

 <service>  
   <provide interface="org.eclipse.e4.core.contexts.IContextFunction"/>  
 </service>  

 <property name="service.context.key" type="String"   
   value="com.example.e4.rcp.todo.contextservice.test"/>  

</scr:component>   

someone must call for the com.example.e4.rcp.todo.contextservice.test for compute to be called but it is unclear to me how this is used.
Does anyone have an example reference?

Answer 1

It is what gets injected into your pojos. E.g.

public class YourPojo {
   @Inject
   @Named("com.example.e4.rcp.todo.contextservice.test")
   private Object yourObject;
}

OR

public class YourPojo {
   @Inject
   public void test(IEclipseContext ctx) {
        Object yourObject = ctx.get("com.example.e4.rcp.todo.contextservice.test");
   }
}

OR

public class YourPojo {
   @Inject
   public void test(@Named("com.example.e4.rcp.todo.contextservice.test") Object yourObject) {
      // consume yourObject
   }
}