Crazy XML study notes (13)---------XML DOM

The XML Document Object Model defines standard methods for accessing and manipulating XML documents.

#DOM treats an XML document as a tree structure, with leaves defined as nodes.

What is XML DOM?

XML DOM is:

• Standard Object Model for XML

• Standard Programming Interface for XML

• Platform and language neutral

• W3C standards

XML DOM defines the objects and attributes of all XML elements, as well as the methods (interfaces) to access them.

In other words:

XML DOM is the standard for getting, changing, adding, or removing XML elements.

XML DOM Node

#Each component in an XML document is a node.

Node

##According to the DOM, each component in the XML document They are all a node.

DOM is stipulated as follows:

• The entire document is a document node

• Each XML tag is an element node

• The text contained in the XML element is a text node

• Each XML attribute is an attribute node

• Comments belong to comment nodes

DOM Example

Please see the following XML file (books.xml):

<?xml version="1.0" encoding="ISO-8859-1"?>

<bookstore>

<book category="children">
  <title lang="en">Harry Potter</title> 
  <author>J K. Rowling</author> 
  <year>2005</year> 
  <price>29.99</price> 
</book>

<book category="cooking">
  <title lang="en">Everyday Italian</title> 
  <author>Giada De Laurentiis</author> 
  <year>2005</year> 
  <price>30.00</price> 
</book>

<book category="web">
  <title lang="en">Learning XML</title> 
  <author>Erik T. Ray</author> 
  <year>2003</year> 
  <price>39.95</price> 
</book>

<book category="web">
  <title lang="en">XQuery Kick Start</title> 
  <author>James McGovern</author> 
  <author>Per Bothner</author> 
  <author>Kurt Cagle</author> 
  <author>James Linn</author> 
  <author>Vaidyanathan Nagarajan</author> 
  <year>2003</year> 
  <price>49.99</price> 
</book>

</bookstore>

In the above XML, the root node is . All other nodes in the document are contained within the .

The root node has four nodes.

The first node has four nodes: