/* ZkExpressionParser.java
{{IS_NOTE
Purpose:
Description:
History:
Nov 5, 2008 11:03:30 AM, 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
Partial codes is based on the Spring Web Flow's WebFlowELExpressionParser
implementation by Keith Donald.
*/
package org.zkoss.spring.webflow.expression.el;
import java.util.ArrayList;
import java.util.List;
import javax.el.ELContext;
import javax.el.ELResolver;
import javax.el.ExpressionFactory;
import javax.el.FunctionMapper;
import javax.el.VariableMapper;
import org.springframework.binding.expression.el.DefaultELResolver;
import org.springframework.binding.expression.el.ELContextFactory;
import org.springframework.binding.expression.el.ELExpressionParser;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.expression.el.ActionMethodELResolver;
import org.springframework.webflow.expression.el.FlowResourceELResolver;
import org.springframework.webflow.expression.el.ImplicitFlowVariableELResolver;
import org.springframework.webflow.expression.el.RequestContextELResolver;
import org.springframework.webflow.expression.el.ScopeSearchingELResolver;
import org.springframework.webflow.expression.el.SpringBeanWebFlowELResolver;
/**
* A ZK-specific ExpressionParser that allows beans and components
* managed by ZK, Spring, or Web Flow to be referenced in
* expressions in the FlowDefinition.
*
* @author henrichen
* @since 1.1
*/
public class ZkExpressionParser extends ELExpressionParser {
/**
* Creates a new ZK Web Flow EL expression parser.
*/
public ZkExpressionParser(ExpressionFactory expressionFactory) {
super(expressionFactory);
putContextFactory(RequestContext.class, new ZkRequestContextELContextFactory());
}
private static class ZkRequestContextELContextFactory implements ELContextFactory {
public ELContext getELContext(Object target) {
final RequestContext context = (RequestContext) target;
final List resolvers = new ArrayList();
resolvers.add(new RequestContextELResolver(context));
resolvers.add(new FlowResourceELResolver(context));
resolvers.add(new ImplicitFlowVariableELResolver(context));
resolvers.add(new ScopeSearchingELResolver(context));
resolvers.add(new SpringBeanWebFlowELResolver(context));
resolvers.add(new ActionMethodELResolver());
resolvers.add(new ZkELResolver()); //resolve ZK variables and implicit object
final ELResolver resolver = new DefaultELResolver(resolvers);
return new ZkWebFlowELContext(resolver);
}
}
private static class ZkWebFlowELContext extends ELContext {
private ELResolver _resolver;
public ZkWebFlowELContext(ELResolver resolver) {
_resolver = resolver;
}
public ELResolver getELResolver() {
return _resolver;
}
public FunctionMapper getFunctionMapper() {
return null;
}
public VariableMapper getVariableMapper() {
return null;
}
}
}