Hi List,
in many of my pages I find myself doing similar things. I collect data with a
form and store it in a SessionState field. Then i forward to a summary page. In
onActivate of summary page check for existence of SessionState value whith
boolean valueExists. If value exists I show the summary and let user confirm.
To save me some code I thought of using Generic base page for that. The code
follows:
public abstract class GenericEntityPage<T> {
@SessionState
private T value;
private boolean valueExists;
public T getValue() {
return this.value;
}
public void setValue(final T value ) {
this.value = value;
}
@OnEvent(value = EventConstants.ACTIVATE)
Object checkValueExists() {
if (!this.valueExists) {
return this.getForwardPage();
}
else {
return null;
}
}
/**
* @return the page to be forwarded to in case value does not exist.
*/
protected abstract Object getForwardPage();
}
Doing so I get an error "Could not find a coercion from type java.lang.Object
to type xyz" on the subclass page. I have looked for inspiration on ars-machina
(http://www.arsmachina.com.br/project/tapestrycrud/usage). But there the
generic values aren't used as SessionState but get/set in the code. Is it
somehow possible to use generic fields as SessionState values?
Kind regards, nillehammer
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