XML DOM Node List
A list of nodes is returned by the getElementsByTagName() method and the childNodes property.
 |
Try it Yourself - 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 the text
from the first <title> element
This example uses the getElementsByTagName() method to get the text from the
first <title> element in "books.xml".
Loop through
nodes using the length property
This example uses node list and the length property to loop through all <title>
elements in "books.xml"
Get the
attribute of an element
This example uses a attribute list to get attribute from the first <book>
element in "books.xml".
DOM Node List
When using properties or methods like childNodes or getElementsByTagName(),
a node list object is returned.
A node list object represents a list of nodes, in the same order as in the
XML.
Nodes in the node list are accessed with index numbers starting from 0.
The following image represents a node list of the <title> elements in "books.xml":
The following code fragment loads "books.xml"
into xmlDoc using loadXMLDoc() and returns a node list of title elements in "books.xml":
xmlDoc=loadXMLDoc("books.xml");
x=xmlDoc.getElementsByTagName("title"); |
After the execution of the statement above, x is a node list object.
The following code fragment returns the text from the first <title> element
in the node list (x):
After the execution of the statement above, txt = "Everyday Italian".
Node List Length
A node list object keeps itself up-to-date. If an element is
deleted or added, the list is automatically
updated.
The length property of a node list is
the number of nodes in the list.
The following code fragment loads "books.xml"
into xmlDoc using loadXMLDoc() and returns the number of <title> elements in "books.xml":
xmlDoc=loadXMLDoc("books.xml");
x=xmlDoc.getElementsByTagName('title').length; |
After the execution of the statement above, x = 4.
The length of the node list can be used to loop through all the elements in the list.
The following code fragment uses the length property to loop through the list of <title> elements:
Example
xmlDoc=loadXMLDoc("books.xml");
//the x variable will hold a node list
x=xmlDoc.getElementsByTagName('title');
for (i=0;i<x.length;i++)
{
document.write(x[i].childNodes[0].nodeValue);
document.write("<br />");
}
|
Output:
Everyday Italian
Harry Potter
XQuery Kick Start
Learning XML
|
Try it yourself »
|
Example explained:
- Load "books.xml"
into xmlDoc using loadXMLDoc()
- Set the x variable to hold a node list of all title elements
- Output the value from the text node of all <title> elements
DOM Attribute List (Named Node Map)
The attributes property of an element node returns a list of attribute nodes.
This is called a named node map, and is similar to a node list, except for
some differences in methods and properties.
A attribute list keeps itself up-to-date. If an attribute is
deleted or added, the list is automatically
updated.
The following code fragment loads "books.xml"
into xmlDoc using loadXMLDoc() and returns a list of attribute nodes from the first <book> element in "books.xml":
xmlDoc=loadXMLDoc("books.xml");
x=xmlDoc.getElementsByTagName('book')[0].attributes; |
After the execution of the code above, x.length = is the number of attributes
and x.getNamedItem() can be used to return an attribute node.
The following code fragment displays the value of the "category"
attribute, and the number of attributes, of a book:
Example
xmlDoc=loadXMLDoc("books.xml");
x=xmlDoc.getElementsByTagName("book")[0].attributes;
document.write(x.getNamedItem("category").nodeValue);
document.write("<br />" + x.length);
|
Output:
Try it yourself »
|
Example explained:
- Load "books.xml"
into xmlDoc using loadXMLDoc()
- Set the x variable to hold a list of all attributes of the first <book>
element
- Output the value from the "category" attribute
- Output the length of the attribute list
Make your web applications look like a million bucks
|
|
Most web applications today use boring methods to present data to their viewers using grids or simple HTML tables. FusionCharts induces "life" into the web applications by converting monotonous data into lively charts, gauges & maps.
FusionCharts works with all technologies like ASP, ASP.NET, PHP, ColdFusion, Ruby on Rails, JSP, HTML pages etc.
and connects to any database to render animated & interactive charts. It takes less than 15 minutes and no expertise
whatsoever to build your first chart and just a glance of it to captivate your audience. This fact is endorsed by our
12,000 customers and 150,000 users which include a majority of the Fortune 500 companies.
And yeah, your applications could look like a million bucks by spending just $69.
So go ahead, download your
copy of FusionCharts and start "wow-ing" your customers now!
|
 |
W3Schools' Online Certification Program
The perfect solution for professionals who need to balance work, family, and career building.
More than 4000 certificates already issued!
|
The HTML Certificate documents your knowledge of HTML, XHTML, and CSS.
The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.
The XML Certificate documents your knowledge of XML, XML DOM and XSLT.
The ASP Certificate documents your knowledge of ASP, SQL, and ADO.
The PHP Certificate documents your knowledge of PHP and SQL (MySQL).
| 
