DTD Examples

📚 DTD Examples

Learn DTD through practical examples covering common scenarios like books, contacts, orders, and more. These real-world examples demonstrate best practices for structuring and validating XML documents effectively.


<!-- Simple DTD structure -->
<!DOCTYPE root [
  <!ELEMENT root (child+)>
  <!ELEMENT child (#PCDATA)>
]>

Example Categories

📖

Book Catalog

Library and bookstore systems

👤

Contact List

Address book and contacts

🛒

Order System

E-commerce and shopping

📰

News Article

Content management systems

🔹 Example 1: Book Catalog

A complete DTD for a library or bookstore catalog system with books, authors, and pricing information including validation rules.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE catalog [
  <!-- Elements -->
  <!ELEMENT catalog (book+)>
  <!ELEMENT book (title,author+,publisher,year,price,description?)>
  <!ELEMENT title (#PCDATA)>
  <!ELEMENT author (firstname,lastname)>
  <!ELEMENT firstname (#PCDATA)>
  <!ELEMENT lastname (#PCDATA)>
  <!ELEMENT publisher (#PCDATA)>
  <!ELEMENT year (#PCDATA)>
  <!ELEMENT price (#PCDATA)>
  <!ELEMENT description (#PCDATA)>
  
  <!-- Attributes -->
  <!ATTLIST book
    id ID #REQUIRED
    isbn CDATA #REQUIRED
    category (fiction|nonfiction|science|history|technology) #REQUIRED
    language CDATA "English">
  
  <!ATTLIST price currency CDATA "USD">
  
  <!-- Entities -->
  <!ENTITY publisher "TechBooks Publishing">
]>

<catalog>
  <book id="B001" isbn="978-1234567890" category="technology">
    <title>Learning XML and DTD</title>
    <author>
      <firstname>John</firstname>
      <lastname>Smith</lastname>
    </author>
    <author>
      <firstname>Jane</firstname>
      <lastname>Doe</lastname>
    </author>
    <publisher>&publisher;</publisher>
    <year>2024</year>
    <price currency="USD">49.99</price>
    <description>
      A comprehensive guide to XML and DTD for beginners.
    </description>
  </book>
  
  <book id="B002" isbn="978-0987654321" category="science">
    <title>Introduction to Physics</title>
    <author>
      <firstname>Albert</firstname>
      <lastname>Newton</lastname>
    </author>
    <publisher>Science Press</publisher>
    <year>2023</year>
    <price currency="EUR">39.99</price>
  </book>
</catalog>

🔹 Example 2: Contact List

An address book DTD with personal and professional contact information, supporting multiple phone numbers and addresses per contact.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE contacts [
  <!-- Elements -->
  <!ELEMENT contacts (contact+)>
  <!ELEMENT contact (name,email+,phone*,address?)>
  <!ELEMENT name (firstname,lastname,middlename?)>
  <!ELEMENT firstname (#PCDATA)>
  <!ELEMENT lastname (#PCDATA)>
  <!ELEMENT middlename (#PCDATA)>
  <!ELEMENT email (#PCDATA)>
  <!ELEMENT phone (#PCDATA)>
  <!ELEMENT address (street,city,state,zip,country)>
  <!ELEMENT street (#PCDATA)>
  <!ELEMENT city (#PCDATA)>
  <!ELEMENT state (#PCDATA)>
  <!ELEMENT zip (#PCDATA)>
  <!ELEMENT country (#PCDATA)>
  
  <!-- Attributes -->
  <!ATTLIST contact
    id ID #REQUIRED
    type (personal|business) #REQUIRED
    favorite (yes|no) "no">
  
  <!ATTLIST phone type (mobile|home|work) #REQUIRED>
  <!ATTLIST email type (personal|work) "personal">
]>

<contacts>
  <contact id="C001" type="business" favorite="yes">
    <name>
      <firstname>John</firstname>
      <middlename>Robert</middlename>
      <lastname>Smith</lastname>
    </name>
    <email type="work">[email protected]</email>
    <email type="personal">[email protected]</email>
    <phone type="mobile">+1-555-0123</phone>
    <phone type="work">+1-555-0124</phone>
    <address>
      <street>123 Business Ave</street>
      <city>New York</city>
      <state>NY</state>
      <zip>10001</zip>
      <country>USA</country>
    </address>
  </contact>
  
  <contact id="C002" type="personal">
    <name>
      <firstname>Jane</firstname>
      <lastname>Doe</lastname>
    </name>
    <email>[email protected]</email>
    <phone type="mobile">+1-555-0125</phone>
  </contact>
</contacts>

🔹 Example 3: E-commerce Order

A complete order system DTD for e-commerce applications with customer information, products, shipping, and payment details.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE order [
  <!-- Elements -->
  <!ELEMENT order (customer,items,shipping,payment,total)>
  <!ELEMENT customer (name,email,phone)>
  <!ELEMENT name (#PCDATA)>
  <!ELEMENT email (#PCDATA)>
  <!ELEMENT phone (#PCDATA)>
  <!ELEMENT items (item+)>
  <!ELEMENT item (product,quantity,price)>
  <!ELEMENT product (#PCDATA)>
  <!ELEMENT quantity (#PCDATA)>
  <!ELEMENT price (#PCDATA)>
  <!ELEMENT shipping (address,method)>
  <!ELEMENT address (#PCDATA)>
  <!ELEMENT method (#PCDATA)>
  <!ELEMENT payment EMPTY>
  <!ELEMENT total (#PCDATA)>
  
  <!-- Attributes -->
  <!ATTLIST order
    id ID #REQUIRED
    date CDATA #REQUIRED
    status (pending|processing|shipped|delivered|cancelled) "pending">
  
  <!ATTLIST item
    id CDATA #REQUIRED
    category (electronics|books|clothing|food) #REQUIRED>
  
  <!ATTLIST payment
    method (credit|debit|paypal|cash) #REQUIRED
    status (pending|completed|failed) "pending">
  
  <!-- Entities -->
  <!ENTITY currency "USD">
  <!ENTITY tax "8.5%">
]>

<order id="ORD001" date="2024-01-15" status="processing">
  <customer>
    <name>Alice Johnson</name>
    <email>[email protected]</email>
    <phone>+1-555-0126</phone>
  </customer>
  
  <items>
    <item id="I001" category="electronics">
      <product>Laptop</product>
      <quantity>1</quantity>
      <price>999.00</price>
    </item>
    <item id="I002" category="electronics">
      <product>Mouse</product>
      <quantity>2</quantity>
      <price>25.00</price>
    </item>
  </items>
  
  <shipping>
    <address>456 Home Street, Boston, MA 02101</address>
    <method>Express Shipping</method>
  </shipping>
  
  <payment method="credit" status="completed"/>
  
  <total>1049.00 &currency; (includes &tax; tax)</total>
</order>

🔹 Example 4: News Article

A content management system DTD for news articles with metadata, authors, categories, and rich text content including multimedia.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article [
  <!-- Elements -->
  <!ELEMENT article (metadata,content,media?,tags?)>
  <!ELEMENT metadata (title,author,published,modified?,category)>
  <!ELEMENT title (#PCDATA)>
  <!ELEMENT author (name,email)>
  <!ELEMENT name (#PCDATA)>
  <!ELEMENT email (#PCDATA)>
  <!ELEMENT published (#PCDATA)>
  <!ELEMENT modified (#PCDATA)>
  <!ELEMENT category (#PCDATA)>
  <!ELEMENT content (paragraph+)>
  <!ELEMENT paragraph (#PCDATA|bold|italic|link)*>
  <!ELEMENT bold (#PCDATA)>
  <!ELEMENT italic (#PCDATA)>
  <!ELEMENT link (#PCDATA)>
  <!ELEMENT media (image|video)*>
  <!ELEMENT image EMPTY>
  <!ELEMENT video EMPTY>
  <!ELEMENT tags (tag+)>
  <!ELEMENT tag (#PCDATA)>
  
  <!-- Attributes -->
  <!ATTLIST article
    id ID #REQUIRED
    lang CDATA "en"
    status (draft|published|archived) "draft">
  
  <!ATTLIST image
    src CDATA #REQUIRED
    alt CDATA #REQUIRED
    width CDATA #IMPLIED
    height CDATA #IMPLIED>
  
  <!ATTLIST video
    src CDATA #REQUIRED
    duration CDATA #IMPLIED>
  
  <!ATTLIST link href CDATA #REQUIRED>
  
  <!-- Entities -->
  <!ENTITY siteName "Tech News Daily">
  <!ENTITY copyright "Copyright &#169; 2024">
]>

<article id="ART001" lang="en" status="published">
  <metadata>
    <title>Introduction to XML DTD</title>
    <author>
      <name>Sarah Williams</name>
      <email>[email protected]</email>
    </author>
    <published>2024-01-15T10:30:00</published>
    <modified>2024-01-16T14:20:00</modified>
    <category>Technology</category>
  </metadata>
  
  <content>
    <paragraph>
      Welcome to &siteName;! Today we explore 
      <bold>XML DTD</bold> and its <italic>practical applications</italic>.
    </paragraph>
    <paragraph>
      DTD helps validate XML documents. Learn more at 
      <link href="https://example.com">our tutorial</link>.
    </paragraph>
    <paragraph>
      This technology is <bold>essential</bold> for modern 
      web development and data exchange systems.
    </paragraph>
  </content>
  
  <media>
    <image 
      src="dtd-diagram.jpg" 
      alt="DTD Structure Diagram" 
      width="800" 
      height="600"/>
    <video 
      src="dtd-tutorial.mp4" 
      duration="05:30"/>
  </media>
  
  <tags>
    <tag>XML</tag>
    <tag>DTD</tag>
    <tag>Tutorial</tag>
    <tag>Web Development</tag>
  </tags>
</article>

🔹 Example 5: Restaurant Menu

A simple restaurant menu DTD demonstrating categories, items, prices, and dietary information for food service applications.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE menu [
  <!ELEMENT menu (restaurant,categories)>
  <!ELEMENT restaurant (name,address,phone)>
  <!ELEMENT name (#PCDATA)>
  <!ELEMENT address (#PCDATA)>
  <!ELEMENT phone (#PCDATA)>
  <!ELEMENT categories (category+)>
  <!ELEMENT category (item+)>
  <!ELEMENT item (name,description,price,calories?)>
  <!ELEMENT description (#PCDATA)>
  <!ELEMENT price (#PCDATA)>
  <!ELEMENT calories (#PCDATA)>
  
  <!ATTLIST category name CDATA #REQUIRED>
  <!ATTLIST item
    id ID #REQUIRED
    vegetarian (yes|no) "no"
    spicy (mild|medium|hot) #IMPLIED>
  
  <!ENTITY currency "$">
]>

<menu>
  <restaurant>
    <name>The Gourmet Kitchen</name>
    <address>789 Food Street, Chicago, IL</address>
    <phone>+1-555-0127</phone>
  </restaurant>
  
  <categories>
    <category name="Appetizers">
      <item id="A001" vegetarian="yes">
        <name>Spring Rolls</name>
        <description>Fresh vegetables wrapped in rice paper</description>
        <price>&currency;8.99</price>
        <calories>180</calories>
      </item>
      <item id="A002" spicy="hot">
        <name>Buffalo Wings</name>
        <description>Spicy chicken wings with blue cheese</description>
        <price>&currency;12.99</price>
        <calories>450</calories>
      </item>
    </category>
    
    <category name="Main Course">
      <item id="M001" vegetarian="yes">
        <name>Vegetable Pasta</name>
        <description>Penne with seasonal vegetables</description>
        <price>&currency;15.99</price>
        <calories>520</calories>
      </item>
      <item id="M002">
        <name>Grilled Salmon</name>
        <description>Fresh Atlantic salmon with herbs</description>
        <price>&currency;24.99</price>
        <calories>380</calories>
      </item>
    </category>
  </categories>
</menu>

🔹 Key Takeaways

DTD Best Practices from Examples:

Clear Structure: Organize elements logically and hierarchically
Appropriate Attributes: Use attributes for IDs, types, and metadata
Entities for Reuse: Define common text and symbols as entities
Occurrence Indicators: Use +, *, ? to control element repetition
Enumerated Values: Restrict attributes to valid options
Optional Elements: Use ? for optional content
Mixed Content: Combine text and elements when needed
Documentation: Comment your DTD for clarity