2015: Intw question 3- Basic Xpath

XPath

• XPath is used to navigate through elements and attributes in an XML document.
• XPath is a language for finding information in an XML document.
• In XPath, there are seven kinds of nodes: 
• element
• attribute
• text
• namespace
• processing-instruction
• comment
• document
• Look at the following XML document:

<?xml version="1.0" encoding="UTF-8"?>

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

Example of nodes in the XML document above:

<bookstore> (root element node)

<author>J K. Rowling</author> (element node)

lang="en" (attribute node)

• Atomic values/Items/Node- Atomic values are nodes with no children or parent. e.g. 

J K. Rowling

"en"

• Relationship of Nodes

Refer following example

<book>
  <title>Harry Potter</title>
  <author>J K. Rowling</author>
  <year>2005</year>
  <price>29.99</price>
</book>

• Parent- Each element and attribute has one parent. e.g. book is parent is of title/author/year/price
• Children- Element nodes may have zero, one or more children. e.g. title/author/year/price are children of book
• Siblings- Nodes that have same parent e.g. title/author/year/price
• Ancestors- Node's parent, parent's parent e.g. book is ancestor of title/author/year/price
• Descendants- Node's children, children's children e.g. title/author/year/price are descendants of book

• Basic XPath Syntax- Refer following article -

       http://www.w3schools.com/xpath/xpath_syntax.asp