Java Doc for ActionElement.java in  » Inversion-of-Control » JICE » org » jicengine » element » Java Source Code / Java DocumentationJava Source Code and Java Documentation

ActionElements can execute an action on request. The request is made by the client or user of the ActionElement, which is usually the parent element.

Typically, ActionElement modify global objects or the instance of the parent element by setting the values of some properties or by calling some methods. ActionElements might also call some static methods.

Design-note: ActionElements don't return any value. the ActionElement-interface is otherwise similar to the ValueElement-interface. The two interfaces could have been put under a common interface, but in that case the action should have returned value. it was essential that action-elements don't return a value. a null-value could have been used for signalling "no value", but that approach works only if we don't use null-values otherwise..

Elements with the 'action'-attribute are compiled into ActionElements. However, also elements without the attribute may end up as ActionElements.

Copyright (C) 2004 Timo Laitinen

Executes the action of this element.

Executes the action of this element. The operation doesn't return any value to its caller, although it can internally produce a value.

The client/user of this element will call this method. currently, the method is called only once. However, the action should be able to be executed multiple times.

in general, the execution consists of the following steps:

1. if the element has an instance, it is created first (with parameters)
2. if the element has other ActionElements as children, they are executed next
3. finally, the actual action is executed (with parameters)