/*
* Copyright 2014 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.grails.web.servlet.view;
import groovy.text.Template;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import grails.web.util.GrailsApplicationAttributes;
import org.grails.web.servlet.mvc.GrailsWebRequest;
import org.grails.web.util.WebUtils;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.servlet.view.AbstractUrlBasedView;
/**
* A view applied to a Grails application that ensures an appropriate web request is bound
*
* @author Lari Hotari
* @since 2.4
*/
public abstract class AbstractGrailsView extends AbstractUrlBasedView {
/**
* Delegates to renderMergedOutputModel(..)
*
* @see #renderMergedOutputModel(java.util.Map, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
*
* @param model The view model
* @param request The HttpServletRequest
* @param response The HttpServletResponse
* @throws Exception When an error occurs rendering the view
*/
@Override
protected final void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
exposeModelAsRequestAttributes(model, request);
renderWithinGrailsWebRequest(model, request, response);
}
private void renderWithinGrailsWebRequest(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response)
throws Exception {
RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
boolean attributesChanged = false;
try {
GrailsWebRequest webRequest;
if(!(requestAttributes instanceof GrailsWebRequest)) {
webRequest = createGrailsWebRequest(request, response, request.getServletContext());
attributesChanged = true;
WebUtils.storeGrailsWebRequest(webRequest);
} else {
webRequest = (GrailsWebRequest)requestAttributes;
}
renderTemplate(model, webRequest, request, response);
} finally {
if(attributesChanged) {
request.removeAttribute(GrailsApplicationAttributes.WEB_REQUEST);
RequestContextHolder.setRequestAttributes(requestAttributes);
}
}
}
/**
* Renders a page with the specified TemplateEngine, mode and response.
* @param model The model to use
* @param request The HttpServletRequest
* @param response The HttpServletResponse instance
* @param engine The TemplateEngine to use
*
* @throws java.io.IOException Thrown when an error occurs writing the response
*/
abstract protected void renderTemplate(Map<String, Object> model, GrailsWebRequest webRequest, HttpServletRequest request, HttpServletResponse response) throws Exception;
protected GrailsWebRequest createGrailsWebRequest(HttpServletRequest request, HttpServletResponse response,
ServletContext servletContext) {
return new GrailsWebRequest(request, response, servletContext);
}
public void rethrowRenderException(Throwable ex, String message) {
if (ex instanceof Error) {
throw (Error) ex;
}
if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
throw new UndeclaredThrowableException(ex, message);
}
abstract public Template getTemplate();
}