zk/src/main/java/org/zkoss/zk/xel/impl/ExecutionResolver.java
/* ExecutionResolver.java
Purpose:
Description:
History:
Fri Jun 24 12:22:23 2005, Created by tomyeh
Copyright (C) 2005 Potix Corporation. All Rights Reserved.
{{IS_RIGHT
This program is distributed under LGPL Version 2.1 in the hope that
it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.zk.xel.impl;
import java.util.Collections;
import org.zkoss.util.resource.Labels;
import org.zkoss.xel.VariableResolver;
import org.zkoss.xel.VariableResolverX;
import org.zkoss.xel.XelContext;
import org.zkoss.xel.XelException;
import org.zkoss.xel.util.Evaluators;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.Components;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.Page;
import org.zkoss.zk.ui.ShadowElement;
import org.zkoss.zk.ui.sys.ExecutionCtrl;
/**
* A variable resolver that is based on the specified execution.
*
* @author tomyeh
* @since 3.0.0
*/
public class ExecutionResolver implements VariableResolverX {
/** The parent resolver. */
private final VariableResolver _parent;
private final Execution _exec;
private Object _self;
/** Constructs a resolver with a parent and a page.
* @param parent the parent resolver (null means ignored).
* @param exec the current execution
*/
public ExecutionResolver(Execution exec, VariableResolver parent) {
if (exec == null)
throw new NullPointerException();
_exec = exec;
_parent = parent;
}
/** Sets the self variable.
* The self variable also acts as the context to resolve other variables.
*/
public void setSelf(Object self) {
_self = self;
}
/** Returns the self variable.
*/
public Object getSelf() {
return _self;
}
//-- VariableResolver --//
public Object resolveVariable(String name) throws XelException {
return resolveVariable(null, null, name);
}
//-- VariableResolverX --//
public Object resolveVariable(XelContext ctx, Object base, Object onm) {
return resolveVariable0(_self, ctx, base, onm);
}
protected Object resolveVariable0(Object self, XelContext ctx, Object base, Object onm) {
if (base != null) {
Object o = ((ExecutionCtrl) _exec).getExtraXelVariable(ctx, base, onm);
if (o != null)
return o;
final Page page = ((ExecutionCtrl) _exec).getCurrentPage();
return page != null ? page.getXelVariable(ctx, base, onm, true) : null;
}
if (onm == null)
return null;
final String name = onm.toString();
if (name == null || name.length() == 0) //just in case
return null;
//Note: we have to access keyword first (rather than component's ns)
//since 1) BeanShell interpreter will store back variables
//and page.getZScriptVariable will return the old value
//2) ZK 5, getAttributeOrFellow doesn't look for variable resolvers and implicit objects
if ("arg".equals(name))
return _exec.getArg();
if ("componentScope".equals(name)) {
if (self instanceof Component)
return ((Component) self).getAttributes(Component.COMPONENT_SCOPE);
return Collections.EMPTY_MAP;
}
if ("desktopScope".equals(name))
return _exec.getDesktop().getAttributes();
if ("desktop".equals(name))
return _exec.getDesktop();
if ("execution".equals(name))
return _exec;
if ("pageScope".equals(name)) {
if (self instanceof Component)
return ((Component) self).getAttributes(Component.PAGE_SCOPE);
if (self instanceof Page)
return ((Page) self).getAttributes();
final Page page = ((ExecutionCtrl) _exec).getCurrentPage();
return page != null ? page.getAttributes() : Collections.EMPTY_MAP;
}
if ("page".equals(name)) {
if (self instanceof Component)
return Components.getCurrentPage((Component) self);
if (self instanceof Page)
return self;
return ((ExecutionCtrl) _exec).getCurrentPage();
}
if ("requestScope".equals(name))
return _exec.getAttributes();
if ("self".equals(name))
return self;
if ("sessionScope".equals(name))
return _exec.getDesktop().getSession().getAttributes();
if ("session".equals(name))
return _exec.getDesktop().getSession();
if ("spaceOwner".equals(name)) {
if (self instanceof Component)
return ((Component) self).getSpaceOwner();
if (self instanceof Page)
return self;
return null;
}
if ("spaceScope".equals(name)) {
if (self instanceof Component)
return ((Component) self).getAttributes(Component.SPACE_SCOPE);
if (self instanceof Page)
return ((Page) self).getAttributes();
return Collections.EMPTY_MAP;
}
if ("param".equals(name) || "paramValues".equals(name))
return Evaluators.resolveVariable(_parent, name);
//Bug 3131983: cannot go through getZScriptVariable
if (self instanceof Component) {
final Component comp = (Component) self;
//We have to look getZScriptVariable first and then namespace
//so it is in the same order of interpreter
Page page = null;
if (comp instanceof ShadowElement) {
final Component host = ((ShadowElement) comp).getShadowHost();
page = Components.getCurrentPage(host);
if (page != null) {
final Object o = page.getZScriptVariable(host, name);
if (o != null)
return o;
}
} else {
page = Components.getCurrentPage(comp);
if (page != null) {
final Object o = page.getZScriptVariable(comp, name);
if (o != null)
return o;
}
}
Object o = _exec.getAttribute(name);
if (o != null/* || _exec.hasAttribute(name)*/) //ServletRequest not support hasAttribute
return o;
o = comp.getShadowVariable(name, true);
if (o != null)
return o;
o = comp.getAttributeOrFellow(name, true);
if (o != null)
return o;
o = ((ExecutionCtrl) _exec).getExtraXelVariable(name);
if (o != null)
return o;
if (page != null) {
o = page.getXelVariable(ctx, null, name, true);
if (o != null)
return o;
}
} else {
Page page;
if (self instanceof Page) {
page = (Page) self;
} else {
page = ((ExecutionCtrl) _exec).getCurrentPage();
}
if (page != null) {
Object o = page.getZScriptVariable(name);
if (o != null)
return o;
o = _exec.getAttribute(name);
if (o != null/* || _exec.hasAttribute(name)*/) //ServletRequest not support hasAttribute
return o;
o = page.getAttributeOrFellow(name, true);
if (o != null)
return o;
o = ((ExecutionCtrl) _exec).getExtraXelVariable(name);
if (o != null)
return o;
o = page.getXelVariable(ctx, null, name, true);
if (o != null)
return o;
} else {
Object o = _exec.getAttribute(name, true);
if (o != null/* || _exec.hasAttribute(name, true)*/) //ServletRequest not support hasAttribute
return o;
}
}
Object o = Evaluators.resolveVariable(_parent, name);
if (o != null)
return o;
//lower priority (i.e., user could override it)
//Reason: they were introduced later, and have to maintain backward comparibility
if ("labels".equals(name))
return Labels.getSegmentedLabels();
return null;
}
//Object//
public String toString() {
return "[ExecutionResolver: " + _self + ']';
}
/**
* A wrapper that prevents _self from being changed in the nested resolving process.
*/
static class Wrapper implements VariableResolverX {
private final ExecutionResolver _resolver;
private final Object _ref;
Wrapper(ExecutionResolver resolver, Object ref) {
this._resolver = resolver;
this._ref = ref;
}
public Object resolveVariable(XelContext ctx, Object base, Object name) throws XelException {
return _resolver.resolveVariable0(_ref, ctx, base, name);
}
public Object resolveVariable(String name) throws XelException {
return _resolver.resolveVariable0(_ref, null, null, name);
}
public String toString() {
return "[ExecutionResolver.Wrapper: " + _ref + ']';
}
}
}