TA Implementation

The basic idea for this initial TA implementation is very simple:

• objects have an activation depth of 0, i.e. by default they are not activated at all;
• whenever a method is called on such an object, the first thing to do before actually executing the method body is to activate the object to level 1, i.e. populating its direct members.

The basic sequence of actions to get this scheme to work is the following:

1. Whenever an object is instantiated from db4o, the database registers itself with this object. To enable this on the database level TransparentActivationSupport has to be registered with the db4o configuration.On the object level an object has to implement the Activatable/IActivatable interface and provide the according bind(activator) method. The default implementation of the bind method will simply store the given activator reference for later use.
2. All methods that are supposed to require activated object fields should call activate()/Activate() at the beginning of the message body. The activate()/Activate() method will check whether the object is already activated. If this is not the case, it will request the container to activate the object to level 1 and set the activated flag accordingly.

Please, remember that the current implementation is subject to change in the next versions.