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XML Tutorials

XML - Extensible Markup Language

• XML used to Exchanging information
• Rigidly Structured documents
• XML content can be displayed on web browser, Personal Digital Assistant (PDA) screens and cell phone screens
• XML is developed by W3c organization
• XML is an open Standard is Shared and available to all

Structured Docs
Loosely Structured
     No Rules and no Order of the items.
Example:

• HTML Page
• Paper Doc

Rigidly structured:
    Strictly follow the Strict Structure and certain parts occur in a particular order with predefined frequency.

Xml Advantages:

• Inability to sort data on the fly
• to separate portion of a document's Content
• No Capabilities for advanced formatting (Equation,Chemical Symbols)
• Specify the meaning of information
• Inefficiencies and bloating caused by adding hundred of tags over the years.

Describe XML document
XML document is made of Information inside tags, with tags nested in a hierarchical and consistent Structure. XML document Begins with the XML Declaration, It tells your web browser or other Computer Appliation that this is an XML Document. XML Declaration is Optional.

Version Attribute is refer the Ms-XMLVersion. Standalone Use 'yes' if the XML document has an internal DTD, use 'no' if the XML document is linked to an external DTD, or any External Decalaration.

• It must Begin and End with a Single tag refered to as the Root tag. After the XML declaration.
• It can contains user defined Element (tags).

Define the Element:
<!Element <Element-name> (Data-type)>

There are three data type:
PCDATA -Handle the Alpha-numeric value.
CDATA - include the Special Character without Specifying the Substituting Character
NDATA -Define the Graphics Files.

Rules for Forming XML Tags:

• An XML documents consists of a string delimited by less than and end with greater than sign.
• Tag name may contain letters or numbers, underscore, dashes, periods.
• Tag names are case sensitive.

Entity:
References the Special Characters (& < > ? ! @ % *..... ).
<!ENTITY <Entity-Name> Value >

• Internal Entity
• External Entity
• Parameter Entity