XML

DTD - Document Type Definition

A DTD defines the layout and expected content for a particular type of XML document.
A parser can use a DTD to determine if a document is valid
DTDs are just one way you can help a parser validate your XML documents.
Another method is to use an XML schema definition.
In contrast to a DTD an XML schema uses XML to define the syntax.

XSD - XML Schema Definition

Its purpose is to define the legal binding blocks of an XML document.
This is an extension to a DTD
It defines the elements and attributes that appear in a document, defines child elements and attributes.

Open XML Developer,

XSLT - XML Stylesheet Language Transformations

This is an XML based language used for transforming one type of XML into another type of XML.
An XSL stylesheet processor accepts data in XML and uses the XMLT definition to transform it into a different XML format.
There are two parts:
Tree Transformation - rules for transforming a source tree into a result tree.
Formatting -

Source Tree XML >> XSL Transform (XSLT) >> Result Tree XML

Well Formed XML

These types of files contain descriptive markup tags.
This doesn't need a DTD
If all the tags are correctly formed and follow XML guidelines the a file is considered to be well formed.
For an XML file to be well formed it must obey the following rules:

• Must contain at least one element

• Must contain a unique opening and closing tag

• All tags must be nested correctly (ie an open and a close)

• XML tags are case sensitive and must be in lowercase

• Attribute values must be enclosed in double quotes

Viewing XML in Visual Studio

2007 Office System - XML schema
save in the following folder:
Program Files \ Microsoft Visual Studio 8 \ XML \ Schemas \ custom.xsd

Common XML Tasks

• Parsing an XML file

• Validating XML against a schema

• Applying an XSL Transform

• Searching intelligently with Xpath

• Serialise an object to XML

• Create an XML schema