simple XML parser for GWT

[musachy]

Here is a couple of classes to parse xml with GWT, the js code is taken
(with some modifications) from
ajaxslt(http://goog-ajaxslt.sourceforge.net/) . Here is how to use it:

String xml = "<element att=\"some attribute\">some text</element>";
Document doc = Document.xmlParse(xml);

Node node0 = (Node)doc.getChildren().get(0);
node0.getName(); // "element"
node0.getValue(); // null
node0.getAttribute("att"); // "some attribute"
node0.getType(); // DOM_ELEMENT_NODE

Node node1 = (Node)node.getChildNodes().get(0);
node1.getName(); // #text
node1.getValue(); // "some text"
node1.getType(); // DOM_TEXT_NODE

this GWT is a lot of fun :)

-----------------------------------------------------------------------------------------

package com.test.client.xml;

import java.util.ArrayList;

import com.google.gwt.core.client.JavaScriptObject;

public class Document {

private ArrayList childNodes = new ArrayList();
public static final String DOM_ELEMENT_NODE = "DOM_ELEMENT_NODE";
public static final String DOM_TEXT_NODE = "DOM_TEXT_NODE";

Document() {
}

//@com.test.client.xml.Document::newDocument()
public static Document newDocument() {
return new Document();
}

//@com.test.client.xml.Document::createNode(Ljava/lang/String;)
public Node createNode(String name) {
return new Node(DOM_ELEMENT_NODE, name, null, this);
}

//@com.test.client.xml.Document::createTextNode(Ljava/lang/String;)
public Node createTextNode(String value) {
return new Node(DOM_TEXT_NODE, "#text", value, this);
}

//@com.test.client.xml.Document::appendChild(Lcom/test/client/xml/Node;)
public void appendChild(Node child) {
childNodes.add(child);
}

//@com.test.client.xml.Document::xmlResolveEntities(Ljava/lang/String;)
public static native JavaScriptObject xmlResolveEntities(String s)
/*-{
var parts =
@com.test.client.xml.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(s,
'&');
var ret = parts[0];
for (var i = 1; i < parts.length; ++i) {
var rp =
@com.test.client.xml.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(parts[i],
';');
if (rp.length == 1) {
// no entity reference: just a & but no ;
ret += parts[i];
continue;
}

var ch;
switch (rp[0]) {
case 'lt':
ch = '<';
break;
case 'gt':
ch = '>';
break;
case 'amp':
ch = '&';
break;
case 'quot':
ch = '"';
break;
case 'apos':
ch = '\'';
break;
case 'nbsp':
ch = String.fromCharCode(160);
break;
default:
// Cool trick: let the DOM do the entity decoding. We assign
// the entity text through non-W3C DOM properties and read it
// through the W3C DOM. W3C DOM access is specified to
resolve
// entities.
var span = $wnd.document.createElement('span');
span.innerHTML = '&' + rp[0] + '; ';
ch = span.childNodes[0].nodeValue.charAt(0);
}
ret += ch + rp[1];
}

return ret;
}-*/
;

//@com.test.client.xml.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)
private static native JavaScriptObject stringSplit(String s, String c)
/*-{
var a = s.indexOf(c);
if (a == -1) {
return [ s ];
}

var parts = [];
parts.push(s.substr(0,a));
while (a != -1) {
var a1 = s.indexOf(c, a + 1);
if (a1 != -1) {
parts.push(s.substr(a + 1, a1 - a - 1));
} else {
parts.push(s.substr(a + 1));
}
a = a1;
}

return parts;
}-*/
;

public static native Document xmlParse(String xml) /*-{
var regex_empty = /\/$/;

// See also <http://www.w3.org/TR/REC-xml/#sec-common-syn> for
// allowed chars in a tag and attribute name. TODO(mesch): the
// following is still not completely correct.

var regex_tagname = /^([\w:-]*)/;
var regex_attribute = /([\w:-]+)\s?=\s?('([^\']*)'|"([^\"]*)")/g;

var xmldoc = @com.test.client.xml.Document::newDocument()();
var root = xmldoc;

// For the record: in Safari, we would create native DOM nodes, but
// in Opera that is not possible, because the DOM only allows HTML
// element nodes to be created, so we have to do our own DOM nodes.

// xmldoc = document.implementation.createDocument('','',null);
// root = xmldoc; // .createDocumentFragment();
// NOTE(mesch): using the DocumentFragment instead of the Document
// crashes my Safari 1.2.4 (v125.12).
var stack = [];

var parent = root;
stack.push(parent);

var x =
@com.test.client.xml.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(xml,
'<');
for (var i = 1; i < x.length; ++i) {
var xx =
@com.test.client.xml.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(x[i],
'>');
var tag = xx[0];
var text =
@com.test.client.xml.Document::xmlResolveEntities(Ljava/lang/String;)(xx[1]
|| '');

if (tag.charAt(0) == '/') {
stack.pop();
parent = stack[stack.length-1];

} else if (tag.charAt(0) == '?') {
// Ignore XML declaration and processing instructions
} else if (tag.charAt(0) == '!') {
// Ignore notation and comments
} else {
var empty = tag.match(regex_empty);
var tagname = regex_tagname.exec(tag)[1];
var node =
xmldoc.@com.test.client.xml.Document::createNode(Ljava/lang/String;)(tagname);

var att;
while (att = regex_attribute.exec(tag)) {
var val =
@com.test.client.xml.Document::xmlResolveEntities(Ljava/lang/String;)(att[3]
|| att[4] || '');

node.@com.test.client.xml.Node::setAttribute(Ljava/lang/String;Ljava/lang/String;)(att[1],
val);
}

//TODO polymorphism here would be nice
if(parent == xmldoc) {

xmldoc.@com.test.client.xml.Document::appendChild(Lcom/test/client/xml/Node;)(node);
}
else {

parent.@com.test.client.xml.Node::appendChild(Lcom/test/client/xml/Node;)(node);
}

if (!empty) {
parent = node;
stack.push(node);
}
}

if (text && parent != root) {
if(parent == xmldoc) {

xmldoc.@com.test.client.xml.Document::appendChild(Lcom/test/client/xml/Node;)(xmldoc.@com.test.client.xml.Document::createTextNode(Ljava/lang/String;)(text));
}
else {

parent.@com.test.client.xml.Node::appendChild(Lcom/test/client/xml/Node;)(xmldoc.@com.test.client.xml.Document::createTextNode(Ljava/lang/String;)(text));
}

}
}

return xmldoc;
}-*/
;

/**
* @return Returns the childNodes.
*/
public ArrayList getChildren() {
return childNodes;
}

}

package com.test.client.xml;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class Node {

private Map attributes = new HashMap();
private ArrayList childNodes = new ArrayList();
private String type;
private String name;
private String value;
private Document document;
private Node parent;

Node(String nodeType, String nodeName, String nodeValue, Document
ownerDocument) {
this.type = nodeType;
this.name = nodeName;
this.value = nodeValue;
this.document = ownerDocument;
}

//@com.test.client.xml.Node::appendChild(Lcom/test/client/xml/Node;)
public void appendChild(Node child) {
child.setParent(this);
childNodes.add(child);
}

public String getAttribute(String name) {
return (String)attributes.get(name);
}

//@com.test.client.xml.Node::appendChild(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)
public void setAttribute(String name, String value) {
attributes.put(name, value);
}

public Node getParent() {
return parent;
}

private void setParent(Node parent) {
this.parent = parent;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getType() {
return type;
}

public void setType(String type) {
this.type = type;
}

public String getValue() {
return value;
}

public void setValue(String value) {
this.value = value;
}

public ArrayList getChildNodes() {
return childNodes;
}

public Document getDocument() {
return document;
}
}

[Henry]

Very cool!

[pabl...@gmail.com]

Throw Exception to me =(

[WARN] Exception thrown into JavaScript
java.lang.RuntimeException: JavaScript method
'@com.mycompany.client.Document::xmlParse(Ljava/lang/String;)' threw an
exception
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.invokeNative(ModuleSpaceIE6.java:365)
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.invokeNativeObject(ModuleSpaceIE6.java:204)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:103)
at com.mycompany.client.Document.xmlParse(Document.java:116)
at
com.mycompany.client.ListUsers$JSONResponseTextHandler.onCompletion(ListUsers.java:29)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at
com.google.gwt.dev.shell.InstanceJavaDispatch.callMethod(InstanceJavaDispatch.java:40)
at
com.google.gwt.dev.shell.ie.IDispatchProxy.invoke(IDispatchProxy.java:117)
Caused by: com.google.gwt.core.client.JavaScriptException: JavaScript
TypeError exception: O objeto não dá suporte para a propriedade ou
método
at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
at
com.google.gwt.dev.shell.ModuleSpace.createJavaScriptException(ModuleSpace.java:267)
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.exceptionCaught(ModuleSpaceIE6.java:76)
at
com.google.gwt.dev.shell.JavaScriptHost.exceptionCaught(JavaScriptHost.java:31)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at
com.google.gwt.dev.shell.StaticJavaDispatch.callMethod(StaticJavaDispatch.java:45)

[musachy]

If you have the mozilla web dev toolbar addon you will be able to see
what is the error. You can also try posting here the xml to see if it
is a bug in the parser.

[pabl...@gmail.com]

Hi!

First Exception

[WARN] Exception thrown into JavaScript

org.eclipse.swt.SWTException: Failed to change Variant type result =
-2147352571
at org.eclipse.swt.ole.win32.OLE.error(OLE.java:332)
at org.eclipse.swt.ole.win32.Variant.getDispatch(Variant.java:331)
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.invokeNativeHandle(ModuleSpaceIE6.java:164)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeHandle(JavaScriptHost.java:79)
at com.mycompany.client.Document.xmlResolveEntities(Document.java:38)

[pabl...@gmail.com]

Compile errors

Output will be written into
D:\java\workspace_gwt\MyProject\www\com.mycompany.MyApplication
Analyzing permutation #1
Errors in
D:\java\workspace_gwt\MyProject\src\com\mycompany\client\Document.java
[ERROR] Line 111: Unresolvable native reference to method
'appendChild' in type 'com.mycom
pany.client.Document' (did you mean
'appendChild(Lcom/mycompany/client/Node;)'?)
[ERROR] Line 111: Unresolvable native reference to method
'appendChild' in type 'com.mycom
pany.client.Node' (did you mean
'appendChild(Lcom/mycompany/client/Node;)'?)
[ERROR] Line 111: Unresolvable native reference to method
'appendChild' in type 'com.mycom
pany.client.Document' (did you mean
'appendChild(Lcom/mycompany/client/Node;)'?)
[ERROR] Line 111: Unresolvable native reference to method
'appendChild' in type 'com.mycom
pany.client.Node' (did you mean
'appendChild(Lcom/mycompany/client/Node;)'?)
[ERROR] Unexpected internal compiler error
[ERROR] Build failed

[musachy]

You need to put the Document and Node classes inside the "client"
package.

[pabl...@gmail.com]

but they are on package 'client'

[pabl...@gmail.com]

Document.java

package com.mycompany.client;

import java.util.ArrayList;

import com.google.gwt.core.client.JavaScriptObject;

public class Document {

private ArrayList childNodes = new ArrayList();

public static final String DOM_ELEMENT_NODE = "DOM_ELEMENT_NODE";

public static final String DOM_TEXT_NODE = "DOM_TEXT_NODE";

Document() {
}

// @com.mycompany.client.Document::newDocument()

public static Document newDocument() {
return new Document();
}

// @com.mycompany.client.Document::createNode(Ljava/lang/String;)

public Node createNode(String name) {
return new Node(DOM_ELEMENT_NODE, name, null, this);
}

// @com.mycompany.client.Document::createTextNode(Ljava/lang/String;)

public Node createTextNode(String value) {
return new Node(DOM_TEXT_NODE, "#text", value, this);
}

//
@com.mycompany.client.Document::appendChild(Lcom/test/client/xml/Node;)

public void appendChild(Node child) {
childNodes.add(child);
}

//
@com.mycompany.client.Document::xmlResolveEntities(Ljava/lang/String;)

public static native JavaScriptObject xmlResolveEntities(String s)
/*-{
var parts =

@com.mycompany.client.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(s,

'&');
var ret = parts[0];
for (var i = 1; i < parts.length; ++i) {
var rp =

@com.mycompany.client.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(parts[i],

return ret;
}-*/
;

//
@com.mycompany.client.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)

private static native JavaScriptObject stringSplit(String s, String c)
/*-{
var a = s.indexOf(c);
if (a == -1) {
return [ s ];
}

var parts = [];
parts.push(s.substr(0,a));
while (a != -1) {
var a1 = s.indexOf(c, a + 1);
if (a1 != -1) {
parts.push(s.substr(a + 1, a1 - a - 1));
} else {
parts.push(s.substr(a + 1));
}
a = a1;
}

return parts;
}-*/
;

public static native Document xmlParse(String xml) /*-{
var regex_empty = /\/$/;

// See also <http://www.w3.org/TR/REC-xml/#sec-common-syn> for
// allowed chars in a tag and attribute name. TODO(mesch): the
// following is still not completely correct.

var regex_tagname = /^([\w:-]*)/;
var regex_attribute = /([\w:-]+)\s?=\s?('([^\']*)'|"([^\"]*)")/g;

var xmldoc = @com.mycompany.client.Document::newDocument()();
var root = xmldoc;

// For the record: in Safari, we would create native DOM nodes, but
// in Opera that is not possible, because the DOM only allows HTML
// element nodes to be created, so we have to do our own DOM nodes.

// xmldoc = document.implementation.createDocument('','',null);
// root = xmldoc; // .createDocumentFragment();
// NOTE(mesch): using the DocumentFragment instead of the Document
// crashes my Safari 1.2.4 (v125.12).
var stack = [];

var parent = root;
stack.push(parent);

var x =
@com.mycompany.client.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(xml,

'<');
for (var i = 1; i < x.length; ++i) {
var xx =

@com.mycompany.client.Document::stringSplit(Ljava/lang/String;Ljava/lang/String;)(x[i],

'>');
var tag = xx[0];
var text =

@com.mycompany.client.Document::xmlResolveEntities(Ljava/lang/String;)(xx[1]
|| '');

if (tag.charAt(0) == '/') {
stack.pop();
parent = stack[stack.length-1];

} else if (tag.charAt(0) == '?') {
// Ignore XML declaration and processing instructions
} else if (tag.charAt(0) == '!') {
// Ignore notation and comments
} else {
var empty = tag.match(regex_empty);
var tagname = regex_tagname.exec(tag)[1];
var node =

xmldoc.@com.mycompany.client.Document::createNode(Ljava/lang/String;)(tagname);

var att;
while (att = regex_attribute.exec(tag)) {
var val =

@com.mycompany.client.Document::xmlResolveEntities(Ljava/lang/String;)(att[3]
|| att[4] || '');

node.@com.mycompany.client.Node::setAttribute(Ljava/lang/String;Ljava/lang/String;)(att[1],
val);
}

//TODO polymorphism here would be nice
if(parent == xmldoc) {

xmldoc.@com.mycompany.client.Document::appendChild(Lcom/test/client/xml/Node;)(node);
}
else {

parent.@com.mycompany.client.Node::appendChild(Lcom/test/client/xml/Node;)(node);
}

if (!empty) {
parent = node;
stack.push(node);
}
}

if (text && parent != root) {
if(parent == xmldoc) {

xmldoc.@com.mycompany.client.Document::appendChild(Lcom/test/client/xml/Node;)(xmldoc.@com.mycompany.client.Document::createTextNode(Ljava/lang/String;)(text));
}
else {

parent.@com.mycompany.client.Node::appendChild(Lcom/test/client/xml/Node;)(xmldoc.@com.mycompany.client.Document::createTextNode(Ljava/lang/String;)(text));

[pabl...@gmail.com]

Node

package com.mycompany.client;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class Node {

private Map attributes = new HashMap();

private ArrayList childNodes = new ArrayList();

private String type;

private String name;

private String value;

private Document document;

private Node parent;

Node(String nodeType, String nodeName, String nodeValue,
Document ownerDocument) {
this.type = nodeType;
this.name = nodeName;
this.value = nodeValue;
this.document = ownerDocument;
}

// @com.mycompany.client.Node::appendChild(Lcom/test/client/xml/Node;)

public void appendChild(Node child) {
child.setParent(this);
childNodes.add(child);
}

public String getAttribute(String name) {
return (String) attributes.get(name);
}

//
@com.mycompany.client.Node::appendChild(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)

[pabl...@gmail.com]

I changed (Lcom/test/client/xml/Node;) to
(Lcom/mycompany/client/Node;), but not works...

[musachy]

The thing is that you need to replace all "com/test/client/xml/" with
your own namespace, in your classes you have this:

com.mycompany.client.Document::appendChild(Lcom/test/client/xml/Node;)

it should be something like:

com.mycompany.client.Document::appendChild(Lcom/mycompany/client/Node;)

replace them all and see if it works.

[pabl...@gmail.com]

Hi musachy, I send e-mail with my code to us, ok?

[musachy]

Hi, I ran your code and it works fine. When you run it in hosted mode
it fails, I forgot to mention that when I posted my code, if you
compile it and run it in the browser it works as expected.

for the GWT folks, this is what we get when running in hosted mode:

[ERROR] Unable to load module entry point class
com.test.client.MyApplication
java.lang.RuntimeException: JavaScript method
'@com.test.client.xml.Document::xmlParse(Ljava/lang/String;)' threw an

exception
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.invokeNative(ModuleSpaceIE6.java:365)
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.invokeNativeObject(ModuleSpaceIE6.java:204)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:103)

at com.test.client.xml.Document.xmlParse(Document.java:114)
at com.test.client.ListUsers.<init>(ListUsers.java:63)
at
com.test.client.ListUsers$ListUsersHolder.<clinit>(ListUsers.java:96)
at com.test.client.ListUsers.getInstance(ListUsers.java:92)
at com.test.client.MyApplication.onModuleLoad(MyApplication.java:38)
at com.google.gwt.dev.shell.ModuleSpace.onLoad(ModuleSpace.java:64)
at
com.google.gwt.dev.shell.BrowserWidget.attachModuleSpace(BrowserWidget.java:324)
Caused by: org.eclipse.swt.SWTException: Failed to change Variant type

result = -2147352571
at org.eclipse.swt.ole.win32.OLE.error(OLE.java:332)
at org.eclipse.swt.ole.win32.Variant.getDispatch(Variant.java:331)
at
com.google.gwt.dev.shell.ie.ModuleSpaceIE6.invokeNativeHandle(ModuleSpaceIE6.java:164)
at
com.google.gwt.dev.shell.JavaScriptHost.invokeNativeHandle(JavaScriptHost.java:79)

at com.test.client.xml.Document.xmlResolveEntities(Document.java:36)
at
com.google.gwt.dev.shell.StaticJavaDispatch.callMethod(StaticJavaDispatch.java:45)
at
com.google.gwt.dev.shell.ie.IDispatchProxy.invoke(IDispatchProxy.java:117)
at
com.google.gwt.dev.shell.ie.IDispatchImpl.Invoke(IDispatchImpl.java:199)
at
com.google.gwt.dev.shell.ie.IDispatchImpl.method6(IDispatchImpl.java:108)
at
org.eclipse.swt.internal.ole.win32.COMObject.callback6(COMObject.java:117)

[pabl...@gmail.com]

Hosted Mode bug? =(

I compile and run Firefox works fine!!!! Thank you

Regards,
Pablo

[eduard.manc...@gmail.com]

This library is nice but it traits the white-spaces as a node text. Is
it a bug?

BTW in hosted mode dont works well but in firefox/ie works well.

[musachy]

Yeah it is probably a bug

[Oh~]

can u provide same demo?

[Pablo Henrique]

Sees here

http://gwt.components.googlepages.com/

On 5/28/06, Oh~ < jj_ly...@yahoo.com.cn> wrote:

can u provide same demo?

[eduard.manc...@gmail.com]

will be a version of the library that runs in hosted mode? or is it
technically imposible?

[musachy]

The guys from google are taking a look at the error, so it will
probably be fixed in a future GWT release.

[Scott Blum]

Hi musachy,

I tracked this down to a semantic problem in Document.

xmlResolveEntities() is declared to return a JavaScriptObject, but in
fact it returns a string primitive. Changing the return type of
xmlResolveEntities() to String fixes the problem. It happens to work
in web mode in this case because you're passing the value directly to
another JSNI method that expects it to really be a string, but
JavaScriptObject is only designed to wrap Object-typed things.

I debugged this by putting "debugger" statements into the JSNI code
and stepping through it with .NET's script debugger on Windows.

Scott

[musachy]

thanks a lot Scott!

[eduard.manc...@gmail.com]

Nice work!

Edu

[Pablo Henrique]

In GWT Version 1.0.21Beta Hosted Mode, work's fine?

On 6/1/06, eduard.manc...@gmail.com <eduard.manc...@gmail.com> wrote:

Nice work!

Edu

[fhab...@gmail.com]

When trying to compile using GWT 1.0.21 I get the below errors. Any
ideas?

Thanks
Fouad
---
$ ./Dashboard-compile.cmd

Output will be written into

c:\workarea\sandbox\projects\eclipse\ikd\www\com.iki
ndi.Dashboard

Analyzing permutation #1
Errors in

C:\workarea\sandbox\projects\eclipse\ikd\src\com\gwt\components\
client\xml\Document.java
[ERROR] Line 54: Expected a valid parameter type signature in
JSNI met
hod reference
[ERROR] Line 147: Expected a valid parameter type signature
in JSNI me
thod reference

[ERROR] Unexpected internal compiler error
[ERROR] Build failed

> ------=_Part_2416_13600445.1149529317164
> Content-Type: text/html; charset=ISO-8859-1
> X-Google-AttachSize: 576
>
> In GWT Version 1.0.21Beta Hosted Mode, work's fine?<br><br><span style="font-size: 9pt; font-family: &quot;Times New Roman&quot;;"></span><div><span class="gmail_quote">On 6/1/06, <b class="gmail_sendername"><a href="mailto:eduard.manc...@gmail.com">
> eduard.manc...@gmail.com</a></b> &lt;<a href="mailto:eduard.manc...@gmail.com">eduard.manc...@gmail.com</a>&gt; wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> <br>Nice work!<br><br>Edu<br><br><br>
> ------=_Part_2416_13600445.1149529317164--

[Pablo Henrique]

Copy this code
http://gwt.components.googlepages.com/simplexmlparser

[fhab...@gmail.com]

Did and compiled but still same problem. Thought perhaps something
related to using java 1.5 so switched to 1.4 but still the same issue.
Any pointer on how to track down?

Thanks

[fhab...@gmail.com]

Got it. It turns out simply copying and pasting the code introduced a
break into calls such as

var parts =
@com.test.client.xml.Document::stringSplit(
Ljava/lang/String;Ljava/lang/String;)(s,'&');

Removing the breaks fixed it.

[Ed Burnette]

I've added this to the gwtPowered Widget List.
http://gwtpowered.dabbledb.com/publish/gwtwidgetlist/d13e5fa1-ce96-4a0f-8aba-b693df88eb2b/gwtwidgetlist.html

[Fitschie]

Hello,

at first many thanks for posting this great source code. After a bit it
works now.

Now I tried to get the Value of Node0. But I alway got one Space.

the XML Document looks like:

<element>
hdsajdsahfdskajhfkldash
</element>

I tried node0.getValue();

Where is the problem?

THX

[Fitschie]

OK I solved the Problem. I realized that the text is in the Childnode.

Thanks
Fitschie

[NorthF...@gmail.com]

Thanks very much!

[djsch...@mitre.org]

I downloaded both the classes and put them in my
src/com/gwt/componets/client/xml folder which corresponds with the
package, then import that into my application java file. However, when
I go to start the application, I get an error that says "The import
com.gwt cannot be resolved". What am I doing wrong?

Thanks,
Dan

[Eugine]

The package "src/com/gwt/componets/client/" is for GWT files, so you
should not be putting these classes there.
Your project files are probably under "com/yourCompanyName/client",
right? That's where you should put the xml-handling classes, simply
because putting them together with the GWT classes involves a lot of
hooking up.

If you're using Eclipse, try simply creating classes "Node" and
"Document" directly in your package explorer and pasting the source
code in will be easiest. I, personally, put the files under
"com/CompanyName/client/xml" - works :]

[djsch...@mitre.org]

Thanks, I did that, and then I had to removed some of the line breaks
because of copying and pasting as in an above mentioned post. Then I
edited the javascript to reflect that change. Now it seems to work.

[Rui Silva]

Great work.
I don't understand one thing, where do i declare somefile.xml to this
sample code catch him and then process it??
Thanks in advance
Rui Silva

[aLeX^rS]

Awesome Post! Thanks guys!

I ran into problems my self, fortunately remedies were posted here so I
needed only to read.

GWT is amazingly fun!

[johnthad]

Are you saying it's not possible to add a separate library to client?

I'm trying to use the XML package posted this week:
edu.gettysburg.xml.client.XML. I've added it to
src/edu/gettysburg/xml/client. I that same src is
src/com/mycompany/webapp/client. When I run MyWebApp-compile, I get

java -cp
"./src:/opt/gwt-linux-1.0.21/gwt-user.jar:/opt/gwt-linux-1.0.21/gwt-dev-linux.jar"
com.google.gwt.dev.GWTCompiler -out "./www" "$@"
com.mycompany.webapp.MyWebApp;
Analyzing source in module 'com.mycompany.webapp.MyWebApp'
[ERROR] Errors in
'/home/dev/JavaDev/gwt/src/com/mycompany/webapp/client/LogoffWidget.java'
[ERROR] Line 19: The import edu cannot be resolved
Finding entry point classes
[ERROR] Unable to find type 'com.mycompany.webapp.client.MyWebApp'
[ERROR] Hint: Previous compiler errors may have made this type
unavailable
[ERROR] Hint: Check the inheritance chain from your module; it
may not beinheriting a required module or a module may not be adding
its source path entries properly
[ERROR] Build failed

Line #19 is `import edu.gettysburg.xml.client.*;`

I have inserted <inherits name='edu.gettysburg.xml.client.XML'/> into
MyWebApp.gwt.xml but it made no difference.

If I have to change the package name for the XML stuff, so be it.
However I would prefer keeping it in it's one package.
com.mycompany.webapp.client stands to get pretty full with just my
stuff without having to toss in other packages.

[Matt Bennett]

> Are you saying it's not possible to add a separate library to client?

I think you might also have to add the jar as a 'lib' entry in your
.classpath file.

[johnthad]

I've tried JAR'ing edu.gettysburg.xml.client and placing that jar in my
classpath but I get the same error message: "The import edu cannot be
resolved"

Is there some dark magic to this that I'm missing? Could my classpath
or the jar itself be wrong?

[Roman Kramar]

Hello,

It's probably a combination of the following steps that is failing in
your case:

1) The folder containing edu/gettysburg/xml/client (or the JAR) should
be in the classpath

2) You should have an .gwt.xml file defining a module for the edu.gettysburg.xml.client
package. Let's assume you have it like this:

edu/gettysburg/xml/client/XmlLib.gwt.xml

3) Your main module should inherit the module from (2). Add the
following line somewhere in your main .gwt.xml:

<inherits name="edu.gettysburg.xml.client.XmlLib"/>

Double check each of the above settings. I'm sure you can make it work.

Regards,
Roman

[johnthad]

The directory src contains both com and edu. I have a gwt.xml module
in edu:

$ ls -R src/edu
src/edu:
gettysburg

src/edu/gettysburg:
xml

src/edu/gettysburg/xml:
client public

src/edu/gettysburg/xml/client:
Element.java Server.java XML.gwt.xml XML.java
Node.java TextNode.java XMLHandler.java

src/edu/gettysburg/xml/public:
menu.txt XML.html

The file XML.gwt.xml contains
<module>
<!-- Inherit the core Web Toolkit stuff. -->
<inherits name='com.google.gwt.user.User'/>

<!-- Specify the app entry point class. -->
<entry-point class='edu.gettysburg.xml.client.XML'/>
</module>

MyWebApp.gwt.xml contains
<inherits name='edu.gettysburg.xml.client.XML'/>

I have tried combinations of this, including leaving the entry point
out of XML.gwt.xml. Always "The import edu cannot be resolved"

I'm not seeing something here. I really need a simple working
application to show me how this is done.

BTW, what is the tag <super-source> in JUnit.gwt.xml ?? It's not in
the docs.

[johnthad]

Finally I blundered around enough to figure this out:

1) I created a new directory and extracted the orginal package. (Dang!
Wish I could remember exactly WHERE it came from. I can't local it in
the threads.)

2) I ran: projectCreator -ant edu.gettysburg.xml.XML
This created edu.gettysburg.xml.XML.ant.xml

3) I ran: ant -buildfile edu.gettysburg.xml.XML.ant.xml package
This created the JAR edu.gettysburg.xml.XML.jar

4) I modified MyWebApp.gwt.xml to add <inherits
name='edu.gettysburg.xml.XML'/>

5) I modified MyWebApp-compile to add edu.gettysburg.xml.XML.jar to the
classpath.

6) I ran MyWebApp-compile WITHOUT ERRORS! Yay!

To test that my package was actually getting use, I ginned up a simple
servlet that returned an XML string:

public class TestXMLServiceImpl extends RemoteServiceServlet implements
TestXMLService
{
public String getTestXML()
{
return "<test>This is a test.</test>";
}
}

I then modified one of my widgets' onLoad() methods to call this
servlet:

protected void onLoad()
{
TestXMLServiceAsync service = (TestXMLServiceAsync)
GWT.create(TestXMLService.class);
ServiceDefTarget target = (ServiceDefTarget) service;
String staticResponseURL = GWT.getModuleBaseURL();
staticResponseURL += "/testxml";
target.setServiceEntryPoint( staticResponseURL );
AsyncCallback callback = new AsyncCallback() {
public void onSuccess( Object result )
{
String document = (String)result;
Node element = Node.parseXML( document );
Window.alert( element.getName() + " - " + element.getText() );
}
public void onFailure(Throwable caught)
{
Window.alert( caught.getMessage() );
caught.printStackTrace();
}
};
service.getTestXML( callback );
}

After some more shenanigans, I got all of this into Tomcat and ran it.
Sure enough, I got an alert "test - This is a test."

Whew!

Now on to writing that killer ant script...

[Mat Gessel]

johnthad wrote:

> BTW, what is the tag <super-source> in JUnit.gwt.xml ?? It's not in
> the docs.

GWT includes a JavaScript implementation of JUnit. The super-source
element tells the compiler where to find this source, relative to the
module root. The compiler will use the JavaScript version instead of
the regular JUnit library.

For example, the classes in this package

> com.google.gwt.junit.translatable.junit.framework

would be interpereted as being in this package

> junit.framework

for the JUnit module.

The same technique was used to rewrite the basic Java library classes
in com.google.gwt.emul.Emulation.

-= Mat

[moez]

hello everybody
i'm new in the GWT world.
to test this XML parser i followed all steps:
- A GWT projet created under eclipse
- A package com.test.client in which i put the 2 files
Document.java et Node.java
- i changed all invalid namespaces by my namespace :com.test.client (as
described in previous posts)
- Now where putting the xml source and how to compile the parser(with
the GWT compiler?)

[Fred Drake]

musachy,

I noticed a bug in the XML Parser when it deals with whitespace around
the element tags. For instance, if I was to parse
"<foo><bar><baz>farkel</baz></bar></foo>" it walks the DOM as expected.
But, if I was to parse:

"
<foo>
<bar>
<baz>
farkel
</baz>
</bar>
</foo>
"

It will pick up the whitespace. If memory serves, the direct children
of the root node are safe, but in this case, the child node list of
<bar> would give me two child nodes: a text node of whitespace and the
<baz> element node.

If it helps, here are the methods I added into my code which strip the
unnecessary whitespace:
private void trimExtraTextFromDocument(Document document) {
for(int i=0; i<document.getChildren().size(); i++) {
trimExtraTextNodes((Node) document.getChildren().get(i));
}
}

private void trimExtraTextNodes(Node node) {
List textSubNodes = new ArrayList();
int subElementNodes = 0;

for(int i=0; i<node.getChildNodes().size(); i++) {
Node subNode = (Node) node.getChildNodes().get(i);
if (subNode.getType().equals(Document.DOM_ELEMENT_NODE)) {
subElementNodes++;
trimExtraTextNodes(subNode);
} else if (subNode.getType().equals(Document.DOM_TEXT_NODE)) {
textSubNodes.add(subNode);
}
}

if (subElementNodes > 0) {
// There can be no text node children if there is at least one
// element node. Nuke all of the text children.
for(int i=0; i<textSubNodes.size(); i++) {
Node textNode = (Node) textSubNodes.get(i);
node.removeChild(textNode);
}
}
}

To use the above code, I added a method to your Node class called
removeChild():

public void removeChild(Node child) {
child.setParent(null);
childNodes.remove(child);
}

Hope this helps.

-Fred