To read and update, create and manipulate an XML document, you will need an XML parser.
Examples
Parse an XML file - Crossbrowser example
This example is a cross-browser example that loads an existing XML document ("note.xml") into the XML parser.
Parse an XML string - Crossbrowser example
This example is a cross-browser example on how to load and parse an XML string.
Parsing XML Documents
To manipulate an XML document, you need an XML parser. The parser loads the document into your computer's memory. Once the document is loaded, its data can be manipulated using the DOM. The DOM treats the XML document as a tree.
To learn more about the XML DOM, please read our XML DOM tutorial.
There are some differences between Microsoft's XML parser and the XML parser used in Mozilla browsers. In this tutorial we will show you how to create cross browser scripts that will work in both Internet Explorer and Mozilla browsers.
Microsoft's XML Parser
Microsoft's XML parser is a COM component that comes with Internet Explorer 5 and higher. Once you have installed Internet Explorer, the parser is available to scripts.
Microsoft's XML parser supports all the necessary functions to traverse the node tree, access the nodes and their attribute values, insert and delete nodes, and convert the node tree back to XML.
To create an instance of Microsoft's XML parser, use the following code:
JavaScript:
var xmlDoc=new ActiveXObject("Microsoft.XMLDOM"); |
VBScript:
set xmlDoc=CreateObject("Microsoft.XMLDOM") |
ASP:
set xmlDoc=Server.CreateObject("Microsoft.XMLDOM") |
The following code fragment loads an existing XML document ("note.xml") into Microsoft's XML parser:
var xmlDoc=new ActiveXObject("Microsoft.XMLDOM"); |
The first line of the script above creates an instance of the XML parser. The second line turns off asynchronized loading, to make sure that the parser will not continue execution of the script before the document is fully loaded. The third line tells the parser to load an XML document called "note.xml".
XML Parser in Mozilla, Firefox, and Opera
Mozilla's XML parser supports all the necessary functions to traverse the node tree, access the nodes and their attribute values, insert and delete nodes, and convert the node tree back to XML.
To create an instance of the XML parser in Mozilla browsers, use the following code:
JavaScript:
var xmlDoc=document.implementation.createDocument("ns","root",null); |
The first parameter, ns, defines the namespace used for the XML document. The second parameter, root, is the XML root element in the XML file. The third parameter, null, is always null because it is not implemented yet.
The following code fragment loads an existing XML document ("note.xml") into Mozillas' XML parser:
var xmlDoc=document.implementation.createDocument("","",null); |
The first line of the script above creates an instance of the XML parser. The second line tells the parser to load an XML document called "note.xml".
Parsing an XML File - A Cross browser Example
The following example is a cross browser example that loads an existing XML document ("note.xml") into the XML parser:
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Output:
W3Schools Internal NoteTo: ToveFrom: Jani Message: Don't forget me this weekend! |
Important Note
To extract the text (Jani) from an XML element like:
getElementsByTagName("from")[0].childNodes[0].nodeValue |
IMPORTANT: getElementsByTagName returns an array of nodes. The array contains all elements with the specified name within the XML document. In this case there is only one "from" element, but you still have to specify the array index ( [0] ).
Parsing an XML String - A Cross browser Example
The following code is a cross-browser example on how to load and parse an XML string:
| |
Output:
| Text of first child element: Tove Text of second child element: Jani |
Note: Internet Explorer uses the loadXML() method to parse an XML string, while Mozilla browsers uses the DOMParser object.
