PSI_ESEI

<xs:complexType name="fullpersoninfo"> <xs:complexContent> <xs:extension base="personinfo">

You don't have to learn a new language You can use your XML editor to edit your Schema files You can use your XML parser to parse your Schema files You can manipulate your Schema with the XML DOM You can transform your Schema with XSLT

XML Schemas are Extensible

Reuse your Schema in other Schemas Create your own data types derived from the standard types Reference multiple schemas in the same document

Well-Formed is not Enough

XML Schema became a W3C Recommendation 02. May 2001.

CDATA Everything inside a CDATA section is ignored by the parser.

A CDATA section starts with "<![CDATA[" and ends with "]]>":

<h:table xmlns:h="http://www.w3.org/TR/html4/">

<f:table xmlns:f="http://www.w3schools.com/furniture">

xmlns:namespace-prefix="namespaceURI"

Note that the address used to identify the namespace is not used by the parser to look up information. The only purpose is to give the namespace a unique name.

Uniform Resource Identifier (URI) A Uniform Resource Identifier (URI) is a string of characters which identifies an Internet Resource. The most common URI is the Uniform Resource Locator (URL) which identifies an Internet domain address.

not so common type of URI is the Universal Resource Name (URN)

Default Namespaces Defining a default namespace for an element saves us from using prefixes in all the child elements.

<table xmlns="http://www.w3.org/TR/html4/">

Use of Elements vs. Attributes Data can be stored in child elements or in attributes.

Should you avoid using attributes? Some of the problems with using attributes are: attributes cannot contain multiple values (child elements can) attributes are not easily expandable (for future changes) attributes cannot describe structures (child elements can) attributes are more difficult to manipulate by program code attribute values are not easy to test against a Document Type Definition (DTD) - which is used to define the legal elements of an XML document

Try to use elements to describe data. Use attributes only to provide information that is not relevant to the data.

root element

parent element

siblings

Elements can have different content types.

An element can have element content, mixed content, simple content, or empty content. An element can also have attributes.

simple content (or text content)

XML elements must follow these naming rules: Names can contain letters, numbers, and other characters Names must not start with a number or punctuation character Names must not start with the letters xml (or XML, or Xml, etc) Names cannot contain spaces

make names descriptive.

Avoid "-" and "." in names

":" should not be used

All XML Elements Must Have a Closing Tag

XML Tags are Case Sensitive

XML Elements Must be Properly Nested

XML Documents Must Have a Root Element

(child elements

XML Attribute Values Must be Quoted

<note date="12/11/2002">

With XML, White Space is Preserved

Comments in XML

<!-- This is a comment -->

changes in the underlying data will not require any changes to your HTML.

XML Can be Used to Create New Languages

With XML, your data is available to more users.

Since XML is independent of hardware, software and application, you can make your data available to other than only standard HTML browsers.

XML can also be used to store data in files or in databases

Since XML data is stored in plain text format, XML provides a software- and hardware-independent way of sharing data.