[WICKET-3776] Implement default onConfigure() using optional Predicate

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 1.4.17
• Component/s: wicket
• Labels: ConfigurationPredicate Predicate component onConfigure setEnabled setVisible
• Assignee: Igor Vaynberg
• Reporter: Russell Morrisey
• Created: 07/Jun/11 19:54
• Updated: 08/Jun/11 15:40
• Resolved: 08/Jun/11 00:22

Description

I would really like to see methods on Component to configure visible and enabled state using a predicate pattern. Ex:

interface ConfigurationPredicate<T extends Component> extends IDetachable {
boolean evaluate(T component);
}
...
DropDownChoice ddc = createDDC(); //my convenience method which sets standard properties, creates a label for the component, and other stuff
ddc.setVisibility(new ConfigurationPredicate<DropDownChoice>() {
public boolean evaluate(DropDownChoice component)

{ myOtherComponent.configure(); return (myOtherComponent.isVisibleInHierarchy()); }

public void detach()

{ myOtherComponent.detach(); }

});

Please consider creating an optional field on Component which can hold a visibility predicate and an enabled state predicate. You can see the advantage clearly in the code above: I don't have to inline my convenience method. I would like composition to be used, instead of inheritance, so I don't have to subclass DropDownChoice just to control the visibility.

Thanks, guys!