com.predic8.membrane.core.interceptor.groovy.GroovyTemplateInterceptor Maven / Gradle / Ivy
/* Copyright 2017 predic8 GmbH, www.predic8.com
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 com.predic8.membrane.core.interceptor.groovy;
import com.predic8.membrane.annot.MCElement;
import com.predic8.membrane.annot.MCTextContent;
import com.predic8.membrane.core.Router;
import com.predic8.membrane.core.exchange.Exchange;
import com.predic8.membrane.core.http.MimeType;
import com.predic8.membrane.core.http.Response;
import com.predic8.membrane.core.interceptor.AbstractInterceptor;
import com.predic8.membrane.core.interceptor.Outcome;
/**
* @description
* Uses the groovy template markup engine to produce HTML-based responses.
*
* <groovyTemplate><![CDATA[
* html {
* head {
* title('Resource')
* }
* body {
* p('Hello from Membrane!')
* }
* }
* ]]></groovyTemplate>
*
*
* The word "spring" refers to the Spring ApplicationContext.
* The word "exc" refers to the Membrane Exchange being handled.
* The word "flow" refers to the current Membrane Flow (=REQUEST).
* @topic 4. Interceptors/Features
*/
@MCElement(name = "groovyTemplate", mixed = true)
public class GroovyTemplateInterceptor extends AbstractInterceptor {
String src = "";
GroovyInterceptor groovyInterceptor;
@Override
public void init(Router router) throws Exception {
super.init(router);
groovyInterceptor = new GroovyInterceptor();
groovyInterceptor.setSrc(createGroovyScript());
groovyInterceptor.init(router);
}
@Override
public Outcome handleRequest(Exchange exc) throws Exception {
groovyInterceptor.handleRequest(exc);
String html = (String) exc.getProperty("GROOVY_TEMPLATE");
exc.setResponse(Response.ok(html).contentType(MimeType.TEXT_HTML_UTF8).build());
return Outcome.RETURN;
}
private String createGroovyScript() {
StringBuilder sb = new StringBuilder();
sb
.append("import groovy.text.markup.*").append("\n")
.append("def markupEngine = new MarkupTemplateEngine()").append("\n")
.append("def writer = new StringWriter()").append("\n")
.append("def markup = '''").append(src).append("'''").append("\n")
.append("def output = markupEngine.createTemplate(markup).make(['spring':spring, 'exc':exc,'flow':flow]).writeTo(writer)").append("\n")
.append("exc.setProperty('GROOVY_TEMPLATE',output.toString())").append("\n")
.append("CONTINUE");
return sb.toString();
}
public String getSrc() {
return src;
}
@MCTextContent
public void setSrc(String src) {
this.src = src;
}
}