Hi,
An Action, as I an sure you are aware, is a unit of work that can be performed on a node.
An Action can have associated with it a optional collection of Conditions. Each Condition can be evaluated against the node and a boolean result obtained. When an action is executed all conditions are evaluated and their results combined with the AND operator. This result is then used to determine whether the action should be executed or not.
A Composite Action extends Actions and allows many actions to be combined together to form singe action.
A Rule extends Composite Action and additionally has information about how the rule should be triggered automatically by the repository when a specific event occures.
So in summary a Rule is simply an Action that can be triggered/executed automatically by the repository.
The saveAction method allows actions to be saved against a node. This means you can create an action (in the same way you can create a rule) and save it against an node for use later. The difference is a saved action, unlike a rule, will never be automatically executed by the repository, it must be executed manually using the executeAction method on the actionService.
UI support for this feature it not currently present, but in the future you could imagine being able to create a custom action, save it against a node and then have these saved actions appear in menus and actions lists in the UI.
I hope this helps to clear-up any confusion,
Roy
