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Parsing and serializing XML

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-Mozilla [http://bugzilla.mozilla.org/show_bug.cgi?id=155749 doesn't support] the W3C's [http://www.w3.org/TR/DOM-Level-3-LS/load-save.html Document Object Model Load and Save] at this moment, so the easiest way to serialize and deserialize DOM trees is to use the following Mozilla-specific interfaces:+Mozilla [https://bugzilla.mozilla.org/show_bug.cgi?id=155749 doesn't support] the W3C's [http://www.w3.org/TR/DOM-Level-3-LS/load-save.html Document Object Model Load and Save] at this moment, so the easiest way to serialize and deserialize DOM trees is to use the following Mozilla-specific interfaces:
*[http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIDOMSerializer.html nsIDOMSerializer] to serialize '''DOM trees to strings or to files''' *[http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIDOMSerializer.html nsIDOMSerializer] to serialize '''DOM trees to strings or to files'''
*[http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIDOMParser.html nsIDOMParser] to parse XML from '''strings into DOM trees''' *[http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIDOMParser.html nsIDOMParser] to parse XML from '''strings into DOM trees'''
-*[http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIXMLHttpRequest.html nsIXMLHttpRequest] to parse XML from '''files into DOM trees''' ([[Using XMLHttpRequest|read more]]). Although [http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIDOMParser.html nsIDOMParser] does have a method named [http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIDOMParser.html#a1 parseFromStream()], it's actually easier to use [http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIXMLHttpRequest.html nsIXMLHttpRequest] (yes, it works for local '''and''' remote files).+*[http://unstable.elemental.com/mozilla/build/latest/mozilla/extensions/dox/interfacensIXMLHttpRequest.html nsIXMLHttpRequest] to parse XML from '''files into DOM trees'''. Although <code>DOMParser</code> does have a method named <code>parseFromStream()</code>, it's actually easier to [[Using XMLHttpRequest|use XMLHttpRequest]] (yes, it works for local '''and''' remote files).

Revision as of 13:40, 10 March 2005

Mozilla doesn't support the W3C's Document Object Model Load and Save at this moment, so the easiest way to serialize and deserialize DOM trees is to use the following Mozilla-specific interfaces:

  • nsIDOMSerializer to serialize DOM trees to strings or to files
  • nsIDOMParser to parse XML from strings into DOM trees
  • nsIXMLHttpRequest to parse XML from files into DOM trees. Although DOMParser does have a method named parseFromStream(), it's actually easier to use XMLHttpRequest (yes, it works for local and remote files).


Contents

Serializing DOM trees to strings

First, create a DOM tree using code like this.

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

var serializer = new XMLSerializer();
var xml = serializer.serializeToString(doc);

Serializing DOM trees to files

First, create a DOM tree using code like this.

Now, let's serialize doc — the DOM tree — to a file (you can read more about using files in Mozilla here):

var serializer = new XMLSerializer();
var foStream = Components.classes["@mozilla.org/network/file-output-stream;1"]
               .createInstance(Components.interfaces.nsIFileOutputStream);
var file = Components.classes["@mozilla.org/file/directory_service;1"]
           .getService(Components.interfaces.nsIProperties)
           .get("ProfD", Components.interfaces.nsIFile); // get profile folder
file.append("extensions");   // extensions sub-directory
file.append("{5872365E-67D1-4AFD-9480-FD293BEBD20D}");   // GUID of your extension
file.append("myXMLFile.xml");   // filename
foStream.init(file, 0x02 | 0x08 | 0x20, 0664, 0);   // write, create, truncate
serializer.serializeToFile(doc, foStream, "IS0-8859-1");   // rememeber, doc is the DOM tree
foStream.close();

Parsing strings into DOM trees

var theString='<a id="a"><b id="b">hey!</b></a>';
var parser = new DOMParser();
var dom = parser.parseFromString(theString, "text/xml");

Parsing files into DOM trees

Coming soon