Showing posts with label XML DOM. Show all posts
Showing posts with label XML DOM. Show all posts

Friday, August 24, 2012

XML DOM


A DOM (Document Object Model) defines a standard way for accessing and manipulating documents.

The XML DOM

The XML DOM defines a standard way for accessing and manipulating XML documents.
The XML DOM views an XML document as a tree-structure.

All elements can be accessed through the DOM tree. Their content (text and attributes) can be modified or deleted, and new elements can be created. The elements, their text, and their attributes are all known as nodes.

You can learn more about the XML DOM in our XML DOM tutorial.

The HTML DOM

The HTML DOM defines a standard way for accessing and manipulating HTML documents.

All HTML elements can be accessed through the HTML DOM.

You can learn more about the HTML DOM in our HTML DOM tutorial.

Load an XML File - Cross-browser Example

The following example parses an XML document ("note.xml") into an XML DOM object and then extracts some info from it with a JavaScript:

Example

<html>
<body>
<h1>W3Schools Internal Note</h1>
<div>
<b>To:</b> <span id="to"></span><br />
<b>From:</b> <span id="from"></span><br />
<b>Message:</b> <span id="message"></span>
</div>

<script type="text/javascript">
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.open("GET","note.xml",false);
xmlhttp.send();
xmlDoc=xmlhttp.responseXML;

document.getElementById("to").innerHTML=
xmlDoc.getElementsByTagName("to")[0].childNodes[0].nodeValue;
document.getElementById("from").innerHTML=
xmlDoc.getElementsByTagName("from")[0].childNodes[0].nodeValue;
document.getElementById("message").innerHTML=
xmlDoc.getElementsByTagName("body")[0].childNodes[0].nodeValue;
</script>

</body>
</html>

Try it yourself »


Important Note!

To extract the text "Tove" from the <to> element in the XML file above ("note.xml"), the syntax is:

getElementsByTagName("to")[0].childNodes[0].nodeValue

Notice that even if the XML file contains only ONE <to> element you still have to specify the array index [0]. This is because the getElementsByTagName() method returns an array.

Load an XML String - Cross-browser Example

The following example parses an XML string into an XML DOM object and then extracts some info from it with a JavaScript:

Example

<html>
<body>
<h1>W3Schools Internal Note</h1>
<div>
<b>To:</b> <span id="to"></span><br />
<b>From:</b> <span id="from"></span><br />
<b>Message:</b> <span id="message"></span>
</div>

<script type="text/javascript">
txt="<note>";
txt=txt+"<to>Tove</to>";
txt=txt+"<from>Jani</from>";
txt=txt+"<heading>Reminder</heading>";
txt=txt+"<body>Don't forget me this weekend!</body>";
txt=txt+"</note>";

if (window.DOMParser)
  {
  parser=new DOMParser();
  xmlDoc=parser.parseFromString(txt,"text/xml");
  }
else // Internet Explorer
  {
  xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
  xmlDoc.async=false;
  xmlDoc.loadXML(txt);
  }

document.getElementById("to").innerHTML=
xmlDoc.getElementsByTagName("to")[0].childNodes[0].nodeValue;
document.getElementById("from").innerHTML=
xmlDoc.getElementsByTagName("from")[0].childNodes[0].nodeValue;
document.getElementById("message").innerHTML=
xmlDoc.getElementsByTagName("body")[0].childNodes[0].nodeValue;
</script>
</body>
</html>

Try it yourself »