/* ZkELResolver.java
{{IS_NOTE
Purpose:
Description:
History:
Nov 7, 2008 1:09:38 PM, Created by henrichen
}}IS_NOTE
Copyright (C) 2008 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under GPL Version 2.0 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.spring.webflow.expression.el;
import java.util.Iterator;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ELResolver;
import javax.el.PropertyNotFoundException;
import javax.el.PropertyNotWritableException;
import org.springframework.webflow.execution.RequestContext;
import org.zkoss.lang.reflect.Fields;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.Executions;
import org.zkoss.zk.ui.IdSpace;
import org.zkoss.zk.ui.Page;
import org.zkoss.zk.ui.event.Event;
/**
* Custom EL resolver that resolves the ZK variables and components.
* @author henrichen
* @since 1.1
*/
public class ZkELResolver extends ELResolver {
public Class getCommonPropertyType(ELContext elContext, Object base) {
if (base == null) {
return RequestContext.class;
}
return null;
}
public Iterator getFeatureDescriptors(ELContext elContext, Object base) {
return null;
}
public Class getType(ELContext elContext, Object base, Object property) {
return null;
}
public Object getValue(ELContext elContext, Object base, Object property) {
if (base == null) {
final Execution exec = Executions.getCurrent();
Object value = null;
if (exec != null) {
final Event event = (Event) exec.getAttribute("actionEvent");
if (event != null && property instanceof String) {
//resolve implicit object
value = resolveZKImplicit(event, exec, (String)property);
//resolve other ZK object
if (value == null) {
final Component comp = (Component) event.getTarget();
value = comp.getAttribute((String)property, false);
}
if (value != null) {
elContext.setPropertyResolved(true);
}
}
}
return value;
} else if (base instanceof Component || base instanceof Page || base instanceof Desktop){
try {
final Object value = Fields.get(base, (String) property);
elContext.setPropertyResolved(true);
return value;
} catch (NoSuchMethodException e) {
return null;
}
} else {
return null;
}
}
private Object resolveZKImplicit(Event event, Execution exec, String fdname) {
if ("event".equals(fdname))
return event;
final Component comp = (Component) event.getTarget();
if ("self".equals(fdname))
return comp;
if ("spaceOwner".equals(fdname))
return comp.getSpaceOwner();
if ("page".equals(fdname))
return comp.getPage();
if ("desktop".equals(fdname))
return comp.getDesktop();
if ("session".equals(fdname))
return comp.getDesktop().getSession();
if ("application".equals(fdname))
return comp.getDesktop().getWebApp();
if ("componentScope".equals(fdname))
return comp.getAttributes();
if ("spaceScope".equals(fdname)) {
final IdSpace spaceOwner = comp.getSpaceOwner();
return (spaceOwner instanceof Page) ?
comp.getPage().getAttributes() : ((Component)spaceOwner).getAttributes();
}
if ("pageScope".equals(fdname))
return comp.getPage().getAttributes();
if ("desktopScope".equals(fdname))
return comp.getDesktop().getAttributes();
if ("sessionScope".equals(fdname))
return comp.getDesktop().getSession().getAttributes();
if ("applicationScope".equals(fdname))
return comp.getDesktop().getWebApp().getAttributes();
if ("requestScope".equals(fdname))
return exec.getAttributes();
if ("execution".equals(fdname))
return exec;
if ("arg".equals(fdname))
return exec.getArg();
if ("param".equals(fdname))
return exec.getParameterMap();
return null;
}
public boolean isReadOnly(ELContext arg0, Object arg1, Object arg2)
throws NullPointerException, PropertyNotFoundException, ELException {
return false;
}
public void setValue(ELContext arg0, Object arg1, Object arg2, Object arg3)
throws NullPointerException, PropertyNotFoundException,
PropertyNotWritableException, ELException {
}
}