Web Technologies

XML

Smt.M.Jeevana Sujitha

Assistant Professor

​

Department of Computer Science and Engineering

SRKR Engineering College, Bhimavaram, A.P. - 534204

OBJECTIVES

The Objectives of this lecture are

• To learn about what is XML and rules for writing XML document.
• To learn about advantages of XML.

XML

• The XML stands for "Extensible Markup Language".
• This is similar to HTML. That means this language contains various tags.
• But those tags are not predefined tags, user can define his own tags.

XML

Difference between HTML & XML:

• The difference between HTML and XML is that HTML is designed for “representation of data” on the web page.
• Where as XML is designed to “transport” or to “store the data”.

XML

Elements and Attributes:

• In XML, the basic entity is element.
• The elements are used for defining the tags.
• The elements consist of opening and closing tag.

Syntax:

<element-name> content </element-name>

Example:

<person>

<person-info>

<name>srinu</name>

<city>palakollu</city>

</person-info>

<hobby>

<first>Reading news paper</first>

<second>Playing cricket</second>

</hobby>

</person>

XML

Rules for writing XML document:

• XML is case sensitive language. Example: <hobby> painting </Hobby>
• In XML each start tag must have matching end tag.

Example: <hobby> painting

• The elements in XML must be properly nested. Example:

<one>

<two> srinu</one>

</two>

XML

Rules for writing XML document:

• A space or tab character is not allowed in the element

name or in attribute name.

Example: <per son> srinu </per son>

• The attributes must be enclosed with double quotes or a

single quote.

Example: <person flag=“true”> </person>

• There are some characters in XML which have special

meanings.

Example:

&lt; for lessthan

&gt; for greater than &amp; for ampersand &quot; for double quotes

Comments in XML document:

XML

• The syntax for writing comments in XML is similar to HTML comments.

Syntax:

<!–- This is comment line -->

XML

Namespace in XML:

• The XML allows us to create different elements which are having the common name. This technique is called “namespace”

Example:

<File-description>

<text fname=“input.txt”>

<describe> It is text file</describe>

</text>

<text fname=“flower.jpg”>

<describe> It is an image file</describe>

</text>

<File-description>

Advantages of XML:

• XML document is human readable
• The XML language is language neutral
• Every XML document has tree structure
• XML is platform independent language

XML

THANK YOU