EXTENSIBLE MARKUP LANGUAGE
(XML)
We are further detail about XML on:-
lXML Syntax
lXML Elements
lXML Attributes
lXML Validation
XML(Extensible Markup Language) was designed to describe data and
focus what data is. It is
a markup language much like
HTML but the tags are not predefined. It uses a DTD or an XML
schema to
describe the data with a DTD or XML Schema is
designed to self-descriptive.
The Difference
Between XML and HTML..!!
lXML
is not a replacement for HTML
lXML
and HTML were designed with different goals:
–XML was designed to transport and
store data, with focus on what data is
–HTML was designed to display
data, with focus on how data looks
lHTML
is about displaying information, while XML is about carrying information
XML
Does not DO Anything because..
lXML was created to structure, store, and transport information
The following example is a note to Tove from Jani, stored as XML:
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>
XML
is Just Plain Text
XML is nothing special because It is just plain text. Any software that can handle plain text
can
also handle XML. However, XML-aware applications can
handle the XML tags specially. The
functional meaning of the tags
depends on the nature of the application.
With
XML You Invent Your Own Tags
The
tags in the example above (like <to> and <from>) are not defined in
any XML standard.
That is because the XML language has no predefined tags. These
tags are "invented" by the
author of the XML document.The
tags used in HTML (and the structure of HTML) are
predefined and HTML
documents can only use tags defined in the HTML standard (like <p>,
<h1>, etc.) but XML
allows the author to define his own tags and his own document structure.
XML
is Not a Replacement for HTML but
lXML
is a complement to HTML
–In most web applications, XML is
used to transport data, while HTML is used to format and display the data
lXML
is a software- and hardware-independent tool for carrying information
XML is actually everywhere. We have been participating in XML development since its
creation. It has been amazing to see how quickly the XML standard has developed,
and how
quickly a large number of software vendors have adopted the standard. XML is now as
important for the Web as HTML was to the foundation of
the Web. It is the most common tool
for data transmissions between all sorts of
applications, and is becoming more and more
popular in the area of storing and
describing information.
How
Can XML be Used?
XML is used in many aspects of web
development, often to simplify data storage and sharing.
THE BENEFITS OF XML
1. XML
Separates Data from HTML
lIf you need to display dynamic data in your HTML document, it will take a lot of work to edit the HTML each time the data changes
lWith XML, data can be stored in separate XML files
lThis way you can concentrate on using HTML for layout and display, and be sure that changes in the underlying data will not require any changes to the HTML
lWith a few lines of JavaScript, you can read an external XML file and update the data content of your HTML
2. XML
Simplifies Data Sharing
lWith XML, data can easily be
exchanged between incompatible systems
lOne of the most time-consuming
challenges for developers is to exchange data between incompatible systems over
the Internet
lExchanging data as XML greatly
reduces this complexity, since the data can be read by different incompatible
applications
3. XML
Simplifies Platform Changes
lUpgrading to new systems (hardware
or software platforms), is always very time consuming
lLarge amounts of data must be
converted and incompatible data is often lost
lXML data is stored in text format
lThis makes it easier to expand or
upgrade to new operating systems, new applications, or new browsers, without
losing data
4. XML
Makes Your Data More Available
lSince XML is independent of
hardware, software and application, XML can make your data more available and
useful
lDifferent applications can access
your data, not only in HTML pages, but also from XML data sources
lWith XML, your data can be
available to all kinds of "reading machines" (Handheld computers,
voice machines, news feeds, etc), and make it more available for
blind people, or people with other disabilities
5. XML
is Used to Create New Internet Languages
lA lot of new Internet
languages are created with XML
lHere are some examples:
–XHTML the latest version of
HTML
–WSDL for describing available web
services
–WAP and WML as markup languages for
handheld devices
–RSS languages for news feeds
–RDF and OWL for describing
resources and ontology
–SMIL for describing multimedia for
the web
No comments:
Post a Comment