【XML】XML DOM

Posted by 西维蜀黍 on 2018-11-12, Last Modified on 2024-05-02

According to the XML DOM, everything in an XML document is a node:

  • The entire document is a document node
  • Every XML element is an element node
  • The text in the XML elements are text nodes
  • Every attribute is an attribute node
  • Comments are comment nodes

The XML DOM Node Tree

The XML DOM views an XML document as a tree-structure. The tree structure is called a node-tree.

All nodes can be accessed through the tree. Their contents can be modified or deleted, and new elements can be created.

The node tree shows the set of nodes, and the connections between them. The tree starts at the root node and branches out to the text nodes at the lowest level of the tree:

Node Parents, Children, and Siblings

The nodes in the node tree have a hierarchical relationship to each other.

The terms parent, child, and sibling are used to describe the relationships. Parent nodes have children. Children on the same level are called siblings (brothers or sisters).

  • In a node tree, the top node is called the root
  • Every node, except the root, has exactly one parent node
  • A node can have any number of children
  • A leaf is a node with no children
  • Siblings are nodes with the same parent-

XML DOM Node Information

Node Properties

In the XML DOM, each node is an object.

Objects have methods and properties, that can be accessed and manipulated by JavaScript.

Three important node properties are:

  • nodeName
  • nodeValue
  • nodeType

The nodeName Property

The nodeName property specifies the name of a node.

  • nodeName is read-only
  • nodeName of an element node is the same as the tag name
  • nodeName of an attribute node is the attribute name
  • nodeName of a text node is always #text
  • nodeName of the document node is always #document

The nodeValue Property

The nodeValue property specifies the value of a node.

  • nodeValue for element nodes is undefined
  • nodeValue for text nodes is the text itself
  • nodeValue for attribute nodes is the attribute value

Reference

https://www.w3schools.com/xml/dom_nodes.asp