1. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 1 Working with XHTML Creating a Well-Formed Valid Document Tutorial 9

2. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 2 Objectives Introducing XHTML Creating a Well-Formed Document Creating a Valid Document Creating an XHTML Document Testing an XHTML Document Using Style Sheets and XHTML

3. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 3 Introducing XHTML SGML (Standard Generalized Markup Language) –can be used with almost any type of document stored in almost any format –Introduced in the 1980s –Metalanguage– used to created other languages HTML –standards get confusing among browsers – can be applied inconsistently

4. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 4 Introducing XHTML XML (Extensible Markup Language) –used to design markup languages XML documents must be evaluated with an XML parser An XML document with correct syntax is a well- formed document A well-formed document with correct content and structure is a valid document DTD specifies correct content and structure

5. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 5 Introducing XHTML XHTML is a reformulation of HTML, written in XML Versions of XHTML

6. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 6 DTDs associated with XHTML 1.0 - transitional: supports many of the presentational features of HTML, including the deprecated elements and attributes Best used for older documents that contain deprecated features

7. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 7 DTDs associated with XHTML 1.0 - frameset: used for documents containing frames, and also supports deprecated elements and attributes

8. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 8 DTDs associated with XHTML 1.0 - strict: does not allow any presentational features or deprecated HTML elements and attributes. Does not support frames or inline frames. It is best used for documents that need to strictly conform to the latest standards.

9. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 9 Creating a Well-Formed Document Rules for well-formed XHTML documents

10. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 10 Creating a Well-Formed Document XHTML documents must also include a single root element that contains all other elements –For XHTML, that root element is the html element Attribute minimization is when some attributes lack attribute values –XHTML doesn’t allow attribute minimization

11. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 11 Attribute minimization in HTML and XHTML

12. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 12 Creating a Valid Document The DTD used depends on the content of the document and the needs of your users To support old browsers, use the transitional DTD To support old browsers in a framed Web site, use the frameset DTD To support more current browsers and want to weed out any use of deprecated features, use the strict DTD

13. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 13 Creating a Valid Document Elements not allowed under the strict DTD: –applet- isindex –basefont- menu –center- s –dir- strike –font- u –iframe

14. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 14 Creating a Valid Document Some attributes are restricted, while others are required in XHTML

15. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 15 Attributes prohibited in the strict DTD

16. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 16 Required XHTML attributes

17. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 17 Creating an XHTML Document The first line of an XTHML document should contain a declaration indicating that the document adheres to the rules and syntax of XML XML (and thus XHTML) documents are based on a character set –A character set is a set of abstract symbols matched to code numbers

18. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 18 Character Sets Universal Character Set (UCS) Unicode Character encoding is the process in which bytes are translated back into characters (when a document is sent across the Internet)

19. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 19 Adding an xml Declaration To declare that a document is written in XML, enter the following as the first line of the file: Where the version attribute indicates the XML version of the document, the encoding attribute specifies the character encoding, and the standalone attribute indicates whether the document contains references to an external DTD.

20. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 20 Adding an xml Declaration For XHTML documents, use the declaration:

21. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 21 The XML Declaration You can also add the DOCTYPE declaration, which tells XML parsers what DTD is associated with the document

22. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 22 The xml Namespace A namespace is a unique identifier for elements and attributes originating from a particular document type (like XHTML or MathML) Two types of namespaces: - default: applied to a root element and any element within it

23. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 23 The xml Namespace local: applies to only select elements - Each element in the local namespace is marked by a prefix attached to the element name xmlns: prefix=“namespace” - Identify any element belonging to that namespace by modifying the element name in the tag: prefix:element

24. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 24 Setting the XHTML Namespace To set XHTML as the default namespace for a document, add the xmlns attribute to the html element with the following value: http://www.w3.org/1999/xhtml

25. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 25 Testing an XHTML Document To test your document, you need to send the file to an XML parser or an XHTML validator Sometimes the same mistake results in several errors are noted in the report - fixing one mistake can solve several errors

26. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 26 Fixing the errors in the paragraph elements

27. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 27 Report showing a successful validation under XHTML 1.0 transitional

28. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 28 Testing an XHTML Document To test under another DTD, you’ll need to change the DOCTYPE declaration Changing the DOCTYPE declaration to XHTML 1.0 strict

29. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 29 Using Style Sheets and XHTML Parsed character data (PCDATA) is text parsed by a browser or parser Unparsed character data (CDATA) is text not processed by the browser or parser

30. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 30 Using Style Sheets and XHTML A CDATA section marks a block of text as CDATA so that parsers ignore any text within it

31. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 31 Tips for Converting old HTML Code to XHTML Include an xml declaration in the first line of your file so that your document can be accessed by XML parsers Add a DOCTYPE declaration for one of the XHTML DTDs and check your document for well- formedness and validity whenever you make a change to the code Add the XHTML default namespace to the html element of your document

32. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 32 Tips for Converting old HTML Code to XHTML Make sure that all element and attribute names are in lowercase letters and that all attribute values are placed in quotes Make sure that all empty elements are entered as one-sided tags. Look especially for improper syntax in the img, hr, and br elements Make sure that all two-sided tags are properly closed. Old HTML code often does not have closing tags for the p element

33. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 33 Tips for Converting old HTML Code to XHTML Make sure that all inline images contain the alt attribute Look for deprecated attributes such as align, bgcolor, and background, and replace them with the float (or text-align), background-color, and background-image styles Replace the name attribute with the id attribute Fix all instances of attribute minimization

34. XP Tutorial 9New Perspectives on Creating Web Pages with HTML, XHTML, and XML 34 Tips for Converting old HTML Code to XHTML Replace the use of the font element with either the span element or with a style that applies the same formatting specified by the font element Replace the use of the width attribute in the td or th element with the width style