XML DTD

|  | Search W3Schools : |

HOME | HTML | CSS | XML | JAVASCRIPT | ASP | PHP | SQL | MORE... |  | References | Examples | Forum | About

ADVERTISEMENTS XML Certification Download XML editor Custom Programming |  |

Table of contents

XML Basic
XML HOME
XML Introduction
XML How to use
XML Tree
XML Syntax
XML Elements
XML Attributes
XML Validation
XML Validator
XML Viewing
XML CSS
XML XSLT
XML JavaScript
XML Parser
XML DOM
XML to HTML
XML HTTP Request
XML Application
XML Advanced
XML Namespaces
XML CDATA
XML Encoding
XML Server
XML DOM Advanced
XML Don't
XML Technologies
XML in Real Life
XML Editors
XML Summary
Examples/Quiz
XML Examples
XML Quiz
XML Exam

Selected Reading

Web Statistics
Web Glossary
Web Hosting
Web Quality
W3Schools Tutorials
W3Schools Forum
Helping W3Schools

# XML Validation

XML with correct syntax is "Well Formed" XML.

XML validated against a DTD is "Valid" XML.

## Well Formed XML Documents

A "Well Formed" XML document has correct XML syntax.

The syntax rules were described in the previous chapters:

- XML documents must have a root element
- XML elements must have a closing tag
- XML tags are case sensitive
- XML elements must be properly nested
- XML attribute values must be quoted

    <?xml version="1.0" encoding="ISO-8859-1"?>
    <note>
    <to>Tove</to>
    <from>Jani</from>
    <heading>Reminder</heading>
    <body>Don't forget me this weekend!</body>
    </note>

## Valid XML Documents

A "Valid" XML document is a "Well Formed" XML document, which also conforms to the rules of a Document Type Definition (DTD):

    <?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE note SYSTEM "Note.dtd">
    <note>
    <to>Tove</to>
    <from>Jani</from>
    <heading>Reminder</heading>
    <body>Don't forget me this weekend!</body>
    </note>

The DOCTYPE declaration in the example above, is a reference to an external DTD file. The content of the file is shown in the paragraph below.

## XML DTD

The purpose of a DTD is to define the structure of an XML document. It defines the structure with a list of legal elements:

    <!DOCTYPE note [
      <!ELEMENT note (to,from,heading,body)>
      <!ELEMENT to      (#PCDATA)>
      <!ELEMENT from    (#PCDATA)>
      <!ELEMENT heading (#PCDATA)>
      <!ELEMENT body    (#PCDATA)>
    ]>

If you want to study DTD, you will find our DTD tutorial on our homepage.

## XML Schema

W3C supports an XML based alternative to DTD called XML Schema:

    <xs:element name="note">

    <xs:complexType>
      <xs:sequence>
        <xs:element name="to"      type="xs:string"/>
        <xs:element name="from"    type="xs:string"/>
        <xs:element name="heading" type="xs:string"/>
        <xs:element name="body"    type="xs:string"/>
      </xs:sequence>
    </xs:complexType>

    </xs:element>

If you want to study XML Schema, you will find our Schema tutorial on our homepage.

## A General XML Validator

To help you check the syntax of your XML files, we have created an XML validator to syntax-check your XML.

Please see the next chapter.

Ektron CMS400.NET Version 7.6 delivers all of the flexibility and features you need to deploy the Web site you want, quickly and efficiently. learn more...

6 ways to take your site to the next level with Ektron:

| Create site stickiness through social networking. Keep it personal, relevant and interactive and they'll come back for more.
| Keep it open. Your site needs to be ready and able to connect to outside services. Ektron's open API gives you maximum flexibility.
| Streamline content and document management. Users need to quickly and intuitively find and add information.
| Empower your content authors. Reduce IT bottlenecks by allowing business users to create and edit Web content and forms.
| Climb to the top of search rankings. SEO tools, URL aliasing and eCommerce for your digital marketing strategy
| Add powerful Web 2.0 tools like blogs, wikis, forums, geo-mapping, rating systems and RSS feeds easily.

See why there are 20,000+ Ektron integrations worldwide. Request an INSTANT DEMO or download a FREE TRIAL today.

WEB HOSTING
Password Protect Your Web Pages
$15 Domain Name Registration Save $20 / year!
Buy UK Domain Names Register Domain Names
Cheap Domain Names Cheap Web Hosting
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
FREE Web Hosting

WEB BUILDING
Website Templates Flash Templates Website Builder Internet Business Opportunity
Custom Programming
FREE Trial or Demo Web Content Manager Forms,Web Alerts,RSS
Download XML editor
FREE Flash Website
FREE Web Templates

EDUCATION
US Web Design Schools
HTML Certification
JavaScript Certification
XML Certification
PHP Certification
ASP Certification

HOME or Top of Page |  | Printer Friendly
W3Schools is for training only. We do not warrant the correctness of its content. The risk from using it lies entirely with the user. While using this site, you agree to have read and accepted our terms of use and privacy policy. Copyright 1999-2009 by Refsnes Data. All Rights Reserved.