/*
* Copyright 2004-2008 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.mvc.builder;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.ContextResource;
import org.springframework.core.io.Resource;
import org.springframework.util.ClassUtils;
import org.springframework.web.servlet.View;
import org.springframework.web.servlet.view.InternalResourceView;
import org.springframework.web.servlet.view.JstlView;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.mvc.view.FlowViewResolver;
/**
* Creates Spring-MVC Internal Resource view to render a flow-relative view resource such as a JSP template.
*
* @see JstlView
* @see InternalResourceView
*
* @author Keith Donald
*/
public class FlowResourceFlowViewResolver implements FlowViewResolver {
private static final boolean JSTL_PRESENT = ClassUtils.isPresent("javax.servlet.jsp.jstl.fmt.LocalizationContext", FlowResourceFlowViewResolver.class.getClassLoader());
private String defaultViewSuffix = ".jsp";
/**
* Returns the default view suffix when selecting views by convention. Default is .jsp.
* @return the default view suffix
*/
public String getDefaultViewSuffix() {
return defaultViewSuffix;
}
/**
* Sets the default suffix for view templates when selecting views by convention. Default is .jsp. Respected when a
* {@link FlowResourceFlowViewResolver} is configured.
* @param defaultViewSuffix the default view suffix
*/
public void setDefaultViewSuffix(String defaultViewSuffix) {
this.defaultViewSuffix = defaultViewSuffix;
}
public View resolveView(String viewId, RequestContext context) {
if (viewId.startsWith("/")) {
return getViewInternal(viewId, context, context.getActiveFlow().getApplicationContext());
} else {
ApplicationContext flowContext = context.getActiveFlow().getApplicationContext();
if (flowContext == null) {
throw new IllegalStateException("A Flow ApplicationContext is required to resolve Flow View Resources");
}
Resource viewResource = flowContext.getResource(viewId);
if (!(viewResource instanceof ContextResource)) {
throw new IllegalStateException(
"A ContextResource is required to get relative view paths within this context");
}
return getViewInternal(((ContextResource) viewResource).getPathWithinContext(), context, flowContext);
}
}
public String getViewIdByConvention(String viewStateId) {
return viewStateId + defaultViewSuffix;
}
// internal helpers
private View getViewInternal(String viewPath, RequestContext context, ApplicationContext flowContext) {
if (viewPath.endsWith(".jsp") || viewPath.endsWith(".jspx")) {
if (JSTL_PRESENT) {
JstlView view = new JstlView(viewPath);
view.setApplicationContext(flowContext);
return view;
} else {
InternalResourceView view = new InternalResourceView(viewPath);
view.setApplicationContext(flowContext);
return view;
}
} else {
throw new IllegalArgumentException("Unsupported view type " + viewPath
+ " only types supported by this FlowViewResolver implementation are [.jsp] and [.jspx]");
}
}
}