stands for EXtensible Markup Languagewas designed to carry data, not to display datais designed to be self-descriptiveis a W3C Recommendatio , February 10, 1998
XML is used in many aspects of web development.XML Separates Data from HTML.XML Simplifies Data Sharing .XML Simplifies Data Transport .XML Simplifies Platform Changes .XML Makes Your Data More Available .
<?xml version="1.0" encoding="ISO-8859-1"?><note> <to>Tove</to> <from>Jani</from> <heading>Reminder</heading> <body>Dont forget me this weekend!</body></note>The first line is the XML declaration .The next line describes the root element (note)The next 4 lines describe 4 child elements of the root(to, from, heading, and body)..
<doc> <parent> computer <em> 4 </em> arab </parent></doc>
An XML document contains XML Elements.An element can contain:Other elements .Text .Attributes .Mix of all of the above .
<bookstore> and <book> have element contents<title>, <author>, <year>, and <price> have text contentXML elements must follow these naming rules:Names can contain letters, numbers, and othercharactersNames cannot start with a number or punctuationcharacterNames cannot start with the letters xml (or XML, orXml, etc)Names cannot contain spaces
XML Attributesattributes provide additional information about elements, <person gender="female"> XML Syntax RulesAll XML Elements Must Have a Closing TagXML Tags are Case Sensitive .XML Elements Must be Properly Nested .Entity References : < <; > >; & &; &apos ‘ ; " ";With XML, the white-space in a document is not truncated,Comments in XML : <!-- This is a comment -->
XML DTD : The purpose of a DTD is to define what elements, attributes and entities is legal in an XML document.XML Schema : XML Schema is an XML based alternative to DTD. EX : <?xml version="1.0" encoding="ISO-8859-1"?> <note> <to>Tove</to> <from>Jani</from> <heading>Reminder</heading> <body>Dont forget me this weekend!</body> </note>
XML is not a replacement for HTML.XML and HTML were designed with different goals:XML was designed to transport and storedata, with focus on what data isHTML was designed to display data, with focus onhow data looksHTML is about displaying information, while XMLis about carrying information
XPATH : is a query language for selecting nodes froman XML documentXpointer , Xlink: : XLink defines a standard way of creating hyperlinks in XML documents ,XPointer allows the hyperlinks to point to morespecific parts (fragments) in the XML document.XSLT: language for transforming XML documents intoother XML documents, or other objects suchas HTMLDOM (DOCUMENT OBJECT MODEL): defines astandard way for accessing and manipulatingdocuments.
XHTML : RELATION BETWEEN XML ANDHTML .WSDL : for describing available web services .WML : as markup languages for handheld devices .RSS : languages for news feeds .SMIL : for describing multimedia for the web .