Class 8 Notes for XML

Learning Objectives:

You will be able to create a valid XML document from a schema

You will be able describe how Xpath works.

Homework:

Schema Practice: Create a DTD and Schema for this XML Document

Read the XPathTutorials from W3schools

Read: Chapter 7

Answer the following Path Questions using Schedule XML:

What is one path to StartTime?

What is the path to EndTime

Answer the following Node Questions using Schedule XML:

What is the Children of Fall Schedule?

Name the Ancestors of Time?

Answer the following questions using cd_catalog.xml (plus give me the path to each!)

What is the sibling of CD.

What is the Child of CD.

What is the Ancestor of CD.

/Catalog/CD/sibling::COUNTRY (give me the path directly to this element)

Topics Covered:

 

Xpath Notation:

Xpath gets you to a Node (a point in an XML Document). Xpath gives you ability to move from that point to another location within a document. Once at the new location, you can grab the data from that Node.

You have seven kinds of nodes that you can access:

element	attribute	text
namespace	comment
processing-instruction	document (root)

The more specific the path to a node the more efficient use of computer resources.

The Syntax for Xpath is similar to DOS for navigating. Xpath Axes and Operators gives you flexibility to travel the document

 

Using Schedule XML Document for an example of a Path inside an XML Document.

/FallSchedule/Class/Title

Document Root vs Root Element (not the same!) Document Node (Starting point for the document)

Define the path and separate it with the elements in the path with a /

// search for the node and start at that point!

 

@ for Attributes

AXES :: notation (example: child::class for schedule would give you Number, Title & DayOfWeek elements)

Ancestor

Parent / (Ancestor for child)

Child

Decedent / (Child of Child)

Sibling (of the Child)

 

Functions are built in ways to move or gather data

Position Functions: position, last, count

Node Functions: name, node (why?) , processing-instruction, comment (not well supported), text

Boolean Functions: true, false, not

Terms:

Xpath, Ancestor, AXES, Boolean, Node, Sibling, Child, Function