/**
* Sencha GXT 3.0.0 - Sencha for GWT
* Copyright(c) 2007-2012, Sencha, Inc.
* licensing@sencha.com
*
* http://www.sencha.com/products/gxt/license/
*/
package com.sencha.gxt.data.client.writer;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Stack;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.Element;
import com.google.gwt.xml.client.XMLParser;
import com.google.web.bindery.autobean.shared.AutoBean;
import com.google.web.bindery.autobean.shared.AutoBeanFactory;
import com.google.web.bindery.autobean.shared.AutoBeanUtils;
import com.google.web.bindery.autobean.shared.AutoBeanVisitor;
import com.sencha.gxt.data.shared.writer.AutoBeanWriter;
/**
* A <code>AutoBeanWriter</code> that outputs XML.
*
* @param <M> the starting data format for the model to be inputed
*/
public class XmlWriter<M> extends AutoBeanWriter<M, String> {
private static class PropertyGetter extends AutoBeanVisitor {
private final Document doc = XMLParser.createDocument();
private final Stack<AutoBean<?>> seen = new Stack<AutoBean<?>>();
private final Stack<Element> currentPath = new Stack<Element>();
public PropertyGetter(String rootTag) {
doc.appendChild(doc.createElement(rootTag));
}
@Override
public void endVisit(AutoBean<?> bean, Context ctx) {
seen.pop();
}
@Override
public void endVisitCollectionProperty(String propertyName, AutoBean<Collection<?>> value,
CollectionPropertyContext ctx) {
for (int i = 0; i < propertyName.split("/").length - 1; i++) {
currentPath.pop();
}
}
@Override
public void endVisitReferenceProperty(String propertyName, AutoBean<?> value, PropertyContext ctx) {
if (!"".equals(propertyName)) {
for (int i = 0; i < propertyName.split("/").length; i++) {
currentPath.pop();
}
}
}
public String getXml() {
assert currentPath.size() == 0;
return doc.toString();
}
@Override
public boolean visit(AutoBean<?> bean, Context ctx) {
if (seen.contains(bean)) {
throw new RuntimeException("Cycle detected serializing beans to xml");
}
seen.push(bean);
return true;
}
@Override
public boolean visitCollectionProperty(String propertyName, AutoBean<Collection<?>> value,
CollectionPropertyContext ctx) {
assertValidPath(propertyName);
List<String> subtags = Arrays.asList(propertyName.split("/"));
List<String> childrenPath = subtags.subList(0, subtags.size() - 1);
Element elt = getCurrentParent();
for (String tag : childrenPath) {
Element next = doc.createElement(tag);
elt.appendChild(next);
elt = next;
currentPath.push(next);
}
String tag = subtags.get(subtags.size() - 1);
for (Object v : value.as()) {
Element next = doc.createElement(tag);
elt.appendChild(next);
currentPath.push(next);
AutoBeanUtils.getAutoBean(v).accept(this);
currentPath.pop();
}
return false;
}
@Override
public boolean visitReferenceProperty(String propertyName, AutoBean<?> value, PropertyContext ctx) {
if ("".equals(propertyName)) {
return true;
}
assertValidPath(propertyName);
String[] subtags = propertyName.split("/");
Element elt = getCurrentParent();
for (String tag : subtags) {
Element next = doc.createElement(tag);
elt.appendChild(next);
elt = next;
currentPath.push(elt);
}
return true;
}
@Override
public boolean visitValueProperty(String propertyName, Object value, PropertyContext ctx) {
assertValidPath(propertyName);
assert propertyName.matches("^([^@]+|.*@[^/]+|)$") : "Invalid path to use when writing data out to XML";
if ("".equals(propertyName)) {
getCurrentParent().appendChild(doc.createTextNode(String.valueOf(value)));
return true;
}
String[] subtags = propertyName.split("/");
Element elt = getCurrentParent();
String attr = null;
for (int i = 0; i < subtags.length; i++) {
if (subtags[i].startsWith("@")) {
assert i + 1 == subtags.length;// this should be caught by the regex
attr = subtags[i].substring(1);
break;
}
Element next = doc.createElement(subtags[i]);
elt.appendChild(next);
elt = next;
}
if (attr != null) {
// TODO better encoding?
elt.setAttribute(attr, String.valueOf(value));
} else {
// TODO better encoding?
elt.appendChild(doc.createTextNode(String.valueOf(value)));
}
return true;
}
protected Element getCurrentParent() {
if (currentPath.size() == 0) {
return doc.getDocumentElement();
}
return currentPath.peek();
}
private void assertValidPath(String path) {
assert !path.contains("[") && !path.contains("]") : "Paths must be simple when used for writing autobeans to xml";
}
}
private final String rootTag;
/**
* Creates a new XML writer that can format an object into XML.
*
* @param factory an auto bean factory that can decode objects of type M
* @param clazz the class to write
* @param rootTag the root tag of the XML document
*/
public XmlWriter(AutoBeanFactory factory, Class<M> clazz, String rootTag) {
super(factory, clazz);
this.rootTag = rootTag;
}
public String write(M model) {
AutoBean<M> autoBean = getAutoBean(model);
PropertyGetter xmlGetter = new PropertyGetter(rootTag);
autoBean.accept(xmlGetter);
return xmlGetter.getXml();
}
}