/*
* Copyright 2004-2012 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.webflow.expression.el;
import java.beans.FeatureDescriptor;
import java.util.Iterator;
import javax.el.ELContext;
import javax.el.ELResolver;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.RequestContextHolder;
/**
* Custom EL resolver that searches the current request context for variables to resolve. The search algorithm looks in
* request scope first, then flash scope, then view scope, then flow scope, then conversation scope.
*
* Suitable for use along side other variable resolvers to support EL binding expressions like "#{bean.property}" where
* "bean" could be a property in any supported scope.
*
* @author Jeremy Grelle
*/
public class ScopeSearchingELResolver extends ELResolver {
private RequestContext requestContext;
public ScopeSearchingELResolver() {
}
public ScopeSearchingELResolver(RequestContext requestContext) {
this.requestContext = requestContext;
}
public Class<?> getCommonPropertyType(ELContext elContext, Object base) {
if (base == null) {
return Object.class;
} else {
return null;
}
}
public Iterator<FeatureDescriptor> getFeatureDescriptors(ELContext elContext, Object base) {
return null;
}
public Class<?> getType(ELContext elContext, Object base, Object property) {
RequestContext requestContext = getRequestContext();
if (base != null || requestContext == null) {
return null;
}
String attributeName = property.toString();
if (requestContext.getRequestScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getRequestScope().get(attributeName).getClass();
} else if (requestContext.getFlashScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getFlashScope().get(attributeName).getClass();
} else if (requestContext.inViewState() && requestContext.getViewScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getViewScope().get(attributeName).getClass();
} else if (requestContext.getFlowScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getFlowScope().get(attributeName).getClass();
} else if (requestContext.getConversationScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getConversationScope().get(attributeName).getClass();
} else {
return null;
}
}
public Object getValue(ELContext elContext, Object base, Object property) {
RequestContext requestContext = getRequestContext();
if (base != null || requestContext == null) {
return null;
}
String attributeName = property.toString();
if (requestContext.getRequestScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getRequestScope().get(attributeName);
} else if (requestContext.getFlashScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getFlashScope().get(attributeName);
} else if (requestContext.inViewState() && requestContext.getViewScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getViewScope().get(attributeName);
} else if (requestContext.getFlowScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getFlowScope().get(attributeName);
} else if (requestContext.getConversationScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return requestContext.getConversationScope().get(attributeName);
} else {
return null;
}
}
public boolean isReadOnly(ELContext elContext, Object base, Object property) {
RequestContext requestContext = getRequestContext();
if (base != null || requestContext == null) {
return false;
}
String attributeName = property.toString();
if (requestContext.getRequestScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return false;
} else if (requestContext.getFlashScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return false;
} else if (requestContext.inViewState() && requestContext.getViewScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return false;
} else if (requestContext.getFlowScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return false;
} else if (requestContext.getConversationScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
return false;
} else {
return false;
}
}
public void setValue(ELContext elContext, Object base, Object property, Object value) {
RequestContext requestContext = getRequestContext();
if (base != null || requestContext == null) {
return;
}
String attributeName = property.toString();
if (requestContext.getRequestScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
requestContext.getRequestScope().put(attributeName, value);
} else if (requestContext.getFlashScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
requestContext.getFlashScope().put(attributeName, value);
} else if (requestContext.inViewState() && requestContext.getViewScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
requestContext.getViewScope().put(attributeName, value);
} else if (requestContext.getFlowScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
requestContext.getFlowScope().put(attributeName, value);
} else if (requestContext.getConversationScope().contains(attributeName)) {
elContext.setPropertyResolved(true);
requestContext.getConversationScope().put(attributeName, value);
}
}
protected RequestContext getRequestContext() {
return requestContext != null ? requestContext : RequestContextHolder.getRequestContext();
}
}