Figure 9: XUI schema - Action
An action defines an act implemented when an event occurred and a relevant condition was examined. This action is meant for a firmly determined target, which concerns a single node or multiple nodes. To indicate the target, you need to formulate the XPath expression.
What needs to be defined for each action?
For each action, define:
Optionally, you may define the reverse action. It is implemented only if the formulated condition has not been met and the condition permits that the reverse action may be implemented (useInverse = true).
Figure 9: XUI schema - Action
Action |
Description |
mainAction |
Main action, executed with the positive examination of the condition. |
inverseAction |
Reverse action (opposite), implemented with the negative examination of the condition.. |
Two types of actions
There are three different types of actions:
Type of action |
Description |
Change of model (propertyChange) |
Sets the value of a data element anew. With the indication of a target in XPath statements, refers to a data element of a simple type. Thus, the new value is set. The model changes can be made on leaf nodes only. If the XPath addresses a complex node, the action is ignored. |
Visual event (uiAction) |
Triggers visual actions. That is, it displays (fades in) or hides (fades out) components, color changes and so on. A target is indicated by an XPath statement. The statement refers to a data element and consequently its representation types. Then, the method (methodName) is executed. The definition of the method name is compliant with the Java Beans Definition |
General Action (generalAction) |
Triggers any kind of action. |
The following example shows an action with a change of model:
<propertyChange>
<formulaExpression>"my change of model"</formulaExpression>
</propertyChange>
To set new model values, use a formula expression. With this expression, you can use complex XPath statements or extended functions. In the above example, the new value "my change of model" is set on the target node.
The following example shows an action with a visual event :
<uiAction methodName="setVisible">
<param name="visible" type="boolean" value="true"/>
</uiAction>
With an UI-action the method name and the parameters, which will be handed over, are required. In the above example the target element is hidden.