/*
* $Id$
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.struts2.views.gxp;
import com.google.gxp.base.GxpContext;
import com.google.gxp.html.HtmlClosure;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.inject.Container;
import com.opensymphony.xwork2.inject.Inject;
import java.io.IOException;
/**
* Struts 2 GXP result type implementation. Outputs GXP. Pulls GXP parameters
* from Struts 2's value stack.
* <p/>
* <p>Declare the GXP result type for your package in the xwork.xml file:</p>
* <p/>
* <pre>
* <result-types>
* <result-type name="gxp" class="org.apache.struts2.views.gxp.GxpResult"/>
* </result-types>
* </pre>
* <p/>
* <p>Or if you want to output XML instead of HTML:</p>
* <p/>
* <pre>
* <result-types>
* <result-type name="gxp" class="org.apache.struts2.views.gxp.GxpResult">
* <param name="outputXml">true</param>
* </result-type>
* </result-types>
* </pre>
* <p/>
* <p>Outputting XML changes the content type from text/html to application/xml
* and configures the {@link GxpContext} to output XML. This is useful in
* situations like specifying the doctype of your GXP to be 'mobile'.</p>
* <p/>
* <p>Use the GXP result type for the result of an action. For example:</p>
* <p/>
* <pre>
* <result name="success" type="gxp">/myPackage/MyGxp.gxp</result>
* </pre>
*
* @author Bob Lee
* @see org.apache.struts2.views.gxp.AbstractGxpResult
*/
public class GxpResult extends AbstractGxpResult {
/**
* Tells Struts 2 which parameter name to use if it's not already specified.
*/
public static final String DEFAULT_PARAM = "gxpName";
private Container container;
private boolean outputXml = false;
/**
* Whether or not this GXP should output XML.
*/
public void setOutputXml(boolean outputXml) {
this.outputXml = outputXml;
}
protected HtmlClosure getGxpClosure() {
final Gxp gxp = getUseInstances() ? GxpInstance.getInstance(getGxpName()) : Gxp.getInstance(getGxpName());
if (null == gxp) {
// TODO(lwerner): OGNL or Struts 2 seems to be swallowing this exception
// rather than logging or rethrowing it, so you never see this message
// TODO(dpb): Is this true now that this work is not done in a setter?
throw new NullPointerException("The GXP " + getGxpName()
+ " could not be loaded. This is probably because you have"
+ " a typo in your config.");
}
container.inject(gxp);
return new HtmlClosure() {
public void write(Appendable out, GxpContext gxpContext) throws IOException {
gxp.write(out, gxpContext);
}
};
}
/**
* Tells the GXP to write itself to the output stream.
*/
public void execute(ActionInvocation actionInvocation) {
GxpResourceProvider provider = getProvider();
try {
getGxpClosure().write(provider.getWriter(), new GxpContext(provider.getLocale(), outputXml));
} catch (Exception e) {
throw new RuntimeException("Exception while rendering "
+ getGxpName()
+ " coming from "
+ actionInvocation.getAction().getClass().getName() + ".",
e);
}
}
/**
* Gets appropriate provider.
*/
GxpResourceProvider getProvider() {
return new HtmlOrXmlProvider(outputXml);
}
/**
* Uses reasonable defaults to provide resources.
*/
private static class HtmlOrXmlProvider extends DefaultProvider {
/**
* Default content-type to use for responses.
*/
private static final String HTML_CONTENT_TYPE = "text/html; charset=UTF-8";
private static final String XML_CONTENT_TYPE = "application/xml; charset=UTF-8";
HtmlOrXmlProvider(boolean outputXml) {
super(outputXml ? XML_CONTENT_TYPE : HTML_CONTENT_TYPE);
}
}
@Inject
public void setContainer(Container container) {
this.container = container;
}
}