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PedroRio - 30 Mar 2011
XEO Web Components - Viewer Events
Viewer Events is a mechanism that allows to interact at the bean level during the life-cycle of a server request. The request life-cyle is depicted in figure 1. There are several points in the request life-cycle in which you can interact, the list is in the following table:
Property |
Description |
onCreateViewPhase |
Occurs the first time a viewer is displayed |
onRestoreViewPhase |
Occurs whenever a request is made to the viewer and it has already been initialized |
beforeApplyRequestValuesPhase |
Occurs before applying request parameters to the components |
afterApplyRequestValuesPhase |
Occurs after applying request parameters to the component |
beforeUpdateModelPhase |
Occurs before applying component values to beans/XEO Model instances |
afterUpdateModelPhase |
Occurs after applying component values to beans/XEO Model instances |
beforeRenderPhase |
Occurs before rendering the current view |
afterRenderPhase |
Occurs after rendering the current view |
All these properties (events) accept an EL Expression to a method with the following signature:
public void myEventMethod( PhaseEvent e);
Let's see an example:
Viewer Declaration:
<xvw:viewer beanClass='MyBean'
beanId='viewBean'
afterUpdateModelPhase= '#{viewBean.afterUpdateModel}'
afterRenderPhase= '#{viewBean.phaseEvent}'
>
Bean:
public class MyBean {
public void afterUpdateModel( PhaseEvent e ) {
System.out.println( "After update Model!!" );
}
public void afterRender( PhaseEvent e ) {
System.out.println( "Before update Model!!" );
}
}
The life-cycle of a server request is depicted in figure 1, bellow:
Figure 1 - The life-cycle of a server request
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