Convertir código a cadena de texto (serializing) y visceversa (parsing) a un XML

Usar una de la siguientes opciones para crear un documento XML (el cual es una instancia de Document).

Por favor vea JXONalgoritmosde reversa.

Usando XMLHttpRequest

Aquí hay un código de ejemplo que lee y codifica un archivo XML con URL direccionable en un árbol del DOM:

var xhr = new XMLHttpRequest();
xhr.onload = function () {
  dump(xhr.responseXML.documentElement.nodeName);
};
xhr.onerror = function () {
  dump("Error mientras se tomaba el XML.");
};
xhr.open("GET", "example.xml");
xhr.responseType = "document";
xhr.send();

xhr.responseXML es una instancia de Document.

Use the following approaches to serialize the contents of the XML document you created in Part 1.

First, create a DOM tree as described in How to Create a DOM tree. Alternatively, use a DOM tree obtained from XMLHttpRequest.

Now, let's serialize doc — the DOM tree — to a string:

var oSerializer = new XMLSerializer();
var sXML = oSerializer.serializeToString(doc);

The new XMLSerializer() constructor is not available from within a JS XPCOM component (or a JS module). Instead, write:

var oSerializer = Components.classes[
  "@mozilla.org/xmlextras/xmlserializer;1"
].createInstance(Components.interfaces.nsIDOMSerializer);
var sXML = oSerializer.serializeToString(doc);

"Pretty" serialization of DOM trees to strings

You can pretty print a DOM tree using XMLSerializer and E4X. First, create a DOM tree as described in the How to Create a DOM tree article. Alternatively, use a DOM tree obtained from XMLHttpRequest. The doc variable contains the DOM tree.

var oSerializer = new XMLSerializer();
var sPrettyXML = XML(oSerializer.serializeToString(doc)).toXMLString();

Indents consist of two spaces. To write a more efficient version or customize the indent string, use treeWalker (en-US).

<content><![CDATA[This is the content]]></content>

Becomes

<content>This is the content</content>

JXON (lossless JavaScript XML Object Notation) is a way to represent JavaScript Objects using XML. To address only parts of an XML document, use XPath instead of converting the whole document into JSON! Otherwise, read the article about JXON.

First, create a DOM tree as described in the How to Create a DOM tree article. If you already have a DOM tree from using XMLHttpRequest, skip to the end of this section.

Now, let's serialize doc, the DOM tree, to a file. For more information about files, see about using files in Mozilla):

var oFOStream = Components.classes[
  "@mozilla.org/network/file-output-stream;1"
].createInstance(Components.interfaces.nsIFileOutputStream);
var oFile = Components.classes["@mozilla.org/file/directory_service;1"]
  .getService(Components.interfaces.nsIProperties)
  .get("ProfD", Components.interfaces.nsILocalFile); // get profile folder
oFile.append("extensions"); // extensions sub-directory
oFile.append("{5872365E-67D1-4AFD-9480-FD293BEBD20D}"); // GUID of your extension
oFile.append("myXMLFile.xml"); // filename
oFOStream.init(oFile, 0x02 | 0x08 | 0x20, 0664, 0); // write, create, truncate
new XMLSerializer().serializeToStream(doc, oFOStream, ""); // rememeber, doc is the DOM tree
oFOStream.close();

If you already have a DOM tree from using XMLHttpRequest, use the same code as above but replace serializer.serializeToStream(doc, oFOStream, "") with serializer.serializeToStream(xmlHttpRequest.responseXML.documentElement, oFOStream, "") where xmlHttpRequest is an instance of XMLHttpRequest.

Note that this first parses the XML retrieved from the server, and then re-serializes it into a stream. Depending on your needs, you could just save the xmlHttpRequest.responseText directly.

If the DOM you have is an HTML document, you can serialize it simply using

var serialized = document.documentElement.innerHTML;

• XPath
• XMLHttpRequest
• JXO