Chapter 3: XML Part I

XML: Extensible Markup Language

• Used to create web pages
• Used to define data
• Used for transferring data between applications
• Based on SGML (Standard Generalized Markup Language) which emphasizes the content of a document over how it is displayed

World Wide Web Consortium

• W3C Website

XML Editors

• We will use Notepad
• Many other free editors exist
• 30 day trial of Dreamweaver

Simple XML Document

• Element (starts with a Tag)
• Element Content
• Attribute
• Value

Adding an XML Declaration

• The ? indicates a processing instruction
• version attribute
• encoding attribute
• standalone attribute

XML Document Parsers

• There are non-validating parsers such as Internet Explorer.
• There are also validating parsers that require a DTD (Document Type Definition). Validating parsers will be discussed in the next chapter.

Well Formed Documents

• Must have a root element
• Are case sensitive
• All elements must be closed, even empty ones
• Nesting must be done properly
• Attributes must be quoted

Predefined Characters

Unicode

• Unicode Home Page (see the Code Charts)
• To use a unicode symbol in an xml document, type something like ખ

Comments

• <!-- comment -->

Monday Exercise

• Work the 15 review questions at the end of Chapter 3. 3 points.
• Construct an .xml file that contains hypothetical ordering information for your e-commerce site. The file should contain information regarding 2 products ordered. It should also include the total due using the Euro symbol. 2 points.

Wednesday Exercise

Work on your e-commerce site. Jack and John will visit each team to provide ungraded feedback.