XML DOM - Get Node Values

From http://www.w3schools.com (Copyright Refsnes Data)

# XML DOM Get Node Values

The nodeValue property is used to get the text value of a node.

The getAttribute() method returns the value of an attribute.

## Examples

The examples below use the XML file books.xml.
A function, loadXMLDoc(), in an external JavaScript is used to load the XML file.

Get an element's value
This example uses the getElementsByTagname() method to get the first <title> element in "books.xml"

Get an attribute's value
This example uses the getAttribute() method to get the value of the "category" attribute of the first <title> element in "books.xml".

## Get the Value of an Element

In the DOM, everything is a node. Element nodes does not have a text value.

The text of an element node is stored in a child node. This node is called a text node.

The way to get the text of an element, is to get the value of the child node (text node).

## Get an Element Value

The getElementsByTagName() method returns a node list containing all elements with the specified tag name in the same order as they appear in the source document.

The following code loads "books.xml" into xmlDoc using loadXMLDoc() and retrieves the first <title> element:

    xmlDoc=loadXMLDoc("books.xml");

    x=xmlDoc.getElementsByTagName("title")[0];

The childNodes property returns a list of child nodes. The <title> element has only one child node. It is a text node.

The following code retrieves the text node of the <title> element:

    x=xmlDoc.getElementsByTagName("title")[0];
    y=x.childNodes[0];

The nodeValue property returns the text value of the text node:

    x=xmlDoc.getElementsByTagName("title")[0];
    y=x.childNodes[0];
    txt=y.nodeValue;

Result: txt = "Everyday Italian"

Try it yourself

Loop through all <title> elements: Try it yourself

## Get the Value of an Attribute

In the DOM, attributes are nodes. Unlike element nodes, attribute nodes have text values.

The way to get the value of an attribute, is to get its text value.

This can be done using the getAttribute() method or using the nodeValue property of the attribute node.

## Get an Attribute Value - getAttribute()

The getAttribute() method returns an attribute value.

The following code retrieves the text value of the "lang" attribute of the first <title> element:

    xmlDoc=loadXMLDoc("books.xml");

    txt=xmlDoc.getElementsByTagName("title")[0].getAttribute("lang");

Result: txt = "en"

Example explained:

1. Load "books.xml" into xmlDoc using loadXMLDoc()
2. Set the txt variable to be the value of the "lang" attribute of the first title element node

Try it yourself

Loop through all <book> elements and get their "category" attributes: Try it yourself

## Get an Attribute Value - getAttributeNode()

The getAttributeNode() method returns an attribute node.

The following code retrieves the text value of the "lang" attribute of the first <title> element:

    xmlDoc=loadXMLDoc("books.xml");

    x=xmlDoc.getElementsByTagName("title")[0].getAttributeNode("lang");
    txt=x.nodeValue;

Result: txt = "en"

Example explained:

1. Load "books.xml" into xmlDoc using loadXMLDoc()
2. Get the "lang" attribute node of the first <title> element node
3. Set the txt variable to be the value of the attribute

Try it yourself

Loop through all <book> elements and get their "category" attributes: Try it yourself

From http://www.w3schools.com (Copyright Refsnes Data)