1 XHTML محمد احمدی نیا

2 Of 19 HTML vs XHTML  XHTML is a stricter and cleaner version of HTML.  by combining the strengths of HTML and XML, XHTML was developed  XHTML is HTML 4.01 redesigned as XML.  correctly and "well-formed“ زبانهای برنامه سازی وب

3 Of 19 What Is XHTML?  XHTML stands for EXtensible HyperText Markup Language  XHTML is almost identical to HTML 4.01  XHTML is a stricter and cleaner version of HTML  XHTML is HTML defined as an XML application  XHTML is a W3C Recommendation of January  XHTML is supported by all major browsers. زبانهای برنامه سازی وب

4 Of 19 Why XHTML?  Many pages on the internet contain "bad" HTML. This is bad HTML Bad HTML This is a paragraph  market consists of different browser technologies  run on computers, mobile phones or other small devices.  Smaller devices often lack the resources or power to interpret a "bad“ code زبانهای برنامه سازی وب

5 Of 19 Differences from HTML  XHTML elements must be properly nested  XHTML elements must always be closed  XHTML elements must be in lowercase  XHTML documents must have one root element زبانهای برنامه سازی وب

6 Of 19 XHTML Syntax  XHTML Elements Must Be Properly Nested  In XHTML, all elements must be properly nested within each other, like this:  This text is bold and italic زبانهای برنامه سازی وب

7 Of 19 XHTML Syntax  Non-empty elements must have a closing tag.  This is wrong:  This is a paragraph This is another paragraph  This is correct:  This is a paragraph This is another paragraph  Empty Elements Must Also Be Closed  A break: A horizontal rule: An image: زبانهای برنامه سازی وب

8 Of 19 XHTML Syntax  XHTML Elements Must Be In Lower Case  Tag names and attributes must be in lower case.  This is wrong:  This is a paragraph  This is correct:  This is a paragraph زبانهای برنامه سازی وب

9 Of 19 XHTML Syntax  XHTML Documents Must Have One Root Element  XHTML elements must be nested within the root element  Child elements must be in pairs and correctly nested  زبانهای برنامه سازی وب

10 Of 19 XHTML Syntax  Attribute Values Must Be Quoted  This is wrong:   This is correct:  زبانهای برنامه سازی وب

11 Of 19 XHTML Syntax  Attribute Minimization Is Forbidden  This is wrong:   This is correct:  زبانهای برنامه سازی وب

12 Of 19 XHTML Syntax  Mandatory XHTML Elements  An XHTML document must have a DOCTYPE declaration.  The html, head, title, and body elements must also be present. زبانهای برنامه سازی وب

13 Of 19 XHTML Doctypes  refers to a Document Type Definition (DTD).  A DTD specifies the rules for the markup language, so that the browsers render the content correctly.  The basic document structure is:  زبانهای برنامه سازی وب

14 Of 19 An XHTML Example Title of document xmlns attribute in, specifies the xml namespace for a document, and is required زبانهای برنامه سازی وب

15 Of 19 XHTML Different Doctypes  XHTML 1.0 Strict  contains all HTML elements and attributes  does NOT INCLUDE presentational or deprecated elements (like font).  Framesets are not allowed.  The markup must also be written as well-formed XML. زبانهای برنامه سازی وب

16 Of 19 XHTML Different Doctypes  XHTML 1.0 Transitional  contains all HTML elements and attributes  INCLUDING presentational and deprecated elements (like font)  Framesets are not allowed  The markup must also be written as well-formed XML زبانهای برنامه سازی وب

17 Of 19 XHTML Different Doctypes  XHTML 1.0 Frameset  This DTD is equal to XHTML 1.0 Transitional, but allows the use of frameset content. زبانهای برنامه سازی وب

18 Of 19 XHTML HowTo  1. Add a  Add an XHTML to the first line of every page:  2. Add an xmlns Attribute  Add an xmlns attribute to the html element of every page:  3. Change Tags And Attribute Names to Lowercase زبانهای برنامه سازی وب

19 Of 19 XHTML HowTo  4. Quote All Attribute Values  Check every page to see that attribute values are quoted.  5. Close all Empty Tags  6. Validate XHTML With The W3C Validator using this url: زبانهای برنامه سازی وب