Title: Introduction to XHTML
1Introduction to XHTML
2Introduction
- Web developers view web pages as documents that
must be created according to authoring and
development guidelines - Web developers use HTML or XHTML to write code of
a web page - Web browsers have a built-in interpreter to
render the results of the code in its window
3What is the World Wide Web
- The World Wide Web (WWW) is most often called the
Web. - The Web is a network of computers all over the
world. - All the computers in the Web can communicate with
each other. - All the computers use a communication standard
called HTTP.
4How does the WWW work?
- Web information is stored in documents called Web
pages. - Web pages are files stored on computers called
Web servers. - Computers reading the Web pages are called Web
clients. - Web clients view the pages with a program called
a Web browser. - Popular browsers are Internet Explorer and
Mozilla Firefox Chrome.
5Web Browsers and Web Servers
- The Web browser makes a request to the web server
- The server which is running an HTTP server that
is listening for requests, receives the request
and locates the document. - The server then sends back the content of the
requested page to the client. - The browser receives the information from the
server and displays the page in the browser
window. The transaction is now complete.
6How to Fetch Web Pages
- A browser fetches a Web page from a server by a
request. - A request is a standard HTTP request containing a
page address. - A page address looks like this
http//www.ibm.com/index.htm.
7Uniform Resource Locator (URL)
- All Web pages are addressed with URLs
- The URL specifies
- A server name
- A directory path
- A filename
- URLs are part of the HTTP (Hypertext Transfer
Protocol) communications protocol.
8Jargon
- URL Uniform Resource Locator
- W3C World Wide Web Consortium
- HTML Hyper-Text Markup Language
- DOCTYPE Document Type Declaration
- XHTML Extensible Hyper-Text Markup Language
- CSS Cascading Style Sheets
9Web Page Displays
- All browsers are designed to display .html and
.htm files - Browsers have to rework their page displays
whenever a browser window is resized - Web pages can look a little different on
different computers - Web page authors cannot completely control their
page displays
10How does the browser display the pages?
- All Web pages contain instructions for display
- The browser displays the page by reading these
instructions. - The most common display instructions are called
XHTML tags. - XHTML tags look like this lth1gtThis is a
headinglt/h1gt.
11The World Wide Web
- Definitions
- HTML
- The HyperText Markup Language
- The language used to structure text-based
information in a document - by denoting certain text as headings, paragraphs,
lists, etc and to supplement that text with
interactive forms, embedded images, and other
multimedia objects - XHTML
- The eXtensible HyperText Markup Language
- XHTML consists of all the elements in HTML 4.01
combined with the syntax of XML. - Allows users to define their own tags for
defining structure, layout, etc.
12Content of Web Pages
- A web site may contain a combination of 13
standard elements - Text Sound
- Lists Video
- Hyperlinks Tables
- Colour Layers
- Graphics Frames
- Images Forms
- Image Maps
13Content of Web Pages
- The content of a web site can be classified as
- Static content does not change regularly e.g.
personal and professional web sites - Dynamic content changes regularly e.g.,
newspaper web sites, weather report sites
14Authoring of Web Pages
- After a web page layout is designed, one needs to
use HTML/XHTML code to implement the design - Introduction to XHTML
- Syntax
- Document Tags
- Authoring tools
- Text formatting
- Special characters
- Hyperlinks
- Lists
- Meta Data
- Colours
- Audio Video
15XHTML Syntax
- XHTML uses tags that are enclosed in brackets lt gt
- XHTML content is contained between tags
- Tags and content form an XHTML element
- Generic element form ltstart-taggt content
ltend-taggt - Start and end tags have the same name, end tag
has a / before it ltbgtThis is BOLDlt/bgt - XHTML tags can be nested according to the first
open, last closed rule ltbgtltigtbold and
italiclt/igtlt/bgt
16XHTML Syntax
- XHTML rules
- Tags must be closed
- XHTML is case sensitive
- Use lower case tags and attribute names, e.g.
width100 - All attribute values must be double quoted, e.g.
100 - Tags must not overlap (i.e., during nesting)
- Comments can be used
- lt!-- This text is a comment --gt
- Do not use obsolete (deprecated) tags
- Browsers ignore misspelled tags (and many other
things!)
17The eXtensible Hypertext Markup Language (XHTML)
- XHTML formatting commands control Web page
displays - All XHTML formatting is achieved with XHTML
elements - All XHTML elements are based on XHTML tags and
tag-pairs - XHTML files can be created with text editors
18Elements of a Page
- Doctype
- Head
- Title
- Body
- HTML
19Tags
- DOCTYPE
- ltHTMLgt
- ltHEADgt
- ltTITLEgt stufflt/TITLEgt
- lt/HEADgt
- ltBODYgt
- ltPgtstuff that people seelt/pgt
- lt/BODYgt
- lt/HTMLgt
20DOCTYPE Avoid Quirks!
- Versions
- Strict lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML
1.0 Strict//EN" "http//www.w3.org/TR/xhtml1/DTD/x
html1-strict.dtd"gt - Transitional lt!DOCTYPE html PUBLIC "-//W3C//DTD
XHTML 1.0 Transitional//EN" http//www.w3.org/TR/x
html1/DTD/xhtml1-transitional.dtdgt
21HEAD
- ltTITLEgt lt/TITLEgt
- ltMETAgt lt/METAgt
- Language, Encoding, Keywords
- Self-closing
- ltmeta Contentgt lt/metagt
- ltmeta Content /gt
- Page Properties
22A HTML Tag Template
- lthtmlgt
- ltheadgt
- lttitlegt
- (insert text for the browsers title bar
here) - lt/titlegt
- lt/headgt
- ltbodygt
- (insert visible Web page elements here)
- lt/bodygt
- lt/htmlgt
23Who is making the Web standards?
- The Web standards ( rule-making body )of the Web
is the W3C. - It is not made up by Mozilla or Microsoft.
- W3C stands for the World Wide Web Consortium.
- W3C puts together specifications for Web
standards. - The most essential Web standards are XHTML, CSS
and XML. - The latest HTML standard is XHTML 2.0
24Markup Languages
- SGML stands for Standard Generalized Markup
Language and was developed in the 1960s as the
first standardized markup language - HTML was developed in the early 1990s as a
lightweight application of SGML for transporting
documents over HTTP - HTML documents were portable among different
operating systems and computer applications - XML was developed to address the limitations of
HTML - XML is a meta-language, or a set of rules, for
building other languages - XML and HTML are both SGLM applications
- XHTML is the successor of HTML
25Origins of Markup Languages
26Overview of XHTML
- The first version of XHTML 1.0, was released in
2000 - W3C description of XHTML
- XHTML 1.0 reformulates HTML as an XML
application. This makes it easier to process and
easier to maintain. XHTML 1.0 borrows elements
and attributes from W3C's earlier work on HTML 4,
and can be interpreted by existing browsers, by
following a few simple guidelines. This allows
you to start using XHTML now! - XHTML is extensible meaning that its element set
is not finite, like that of HTML. Additional
elements or other XML-based languages can be
integrated with XHTML - XHTML consists of the element set of HTML
reformulated to adhere to the syntax rules of XML - XHTML is compatible with existing web browser
technology and will be compatible with future
XML-based clients
27Building XHTML Documents
- Elements consist of a start tag, content and an
end tag -
-
- lth1gt Introduction to XHTMLlt/h1gt
- Empty elements are used to describe elements that
do not have any content ltbr /gt - Attributes are used to describe elements and are
placed inside the open tag of an element - ltimg srcpicture.jpg alt This is my picture
/gt - alt attribute specifies an alternate text for an
image - Comments are used to notate the document, but are
not processed by parsers - lt!-- This is a comment --gt
Content
Start Tag
End Tag
28Three Flavors of XHTML 1.0
- XHTML 1.0 Transitional
- This DTD 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.lt!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http//www.w3.org/TR/xhtml1/DTD/xhtml1-transition
al.dtd"gt - XHTML 1.0 Strict
- This DTD contains all HTML elements and
attributes, but does NOT INCLUDE presentational
or deprecated elements (like font). Framesets are
not allowed. The markup must also be written as
well-formed XML. - lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" "http//www.w3.org/TR/xhtml1/DTD/xhtml
1-strict.dtd"gt - XHTML 1.0 Frameset
- This DTD is equal to XHTML 1.0 Transitional, but
allows the use of frameset content. - lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Frameset//EN" "http//www.w3.org/TR/xhtml1/DTD/xht
ml1-frameset.dtd"gt
29Document Tags
- The tags that make up the framework of a typical
XHTML document include the following - Document type definition (DTD) tag DOCTYPE
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-strict.
dtd"gt - Describes (to web browsers) what type/version of
(x)html is used - Specifies rules that apply to the markup of
documents - Used for document syntax validation (e.g. strict)
and for web browser to process document in proper
parsing mode (impacts on consistency and speed
of display) - An XHTML document is validated against a Document
Type Definition. - Top-level tag, generally lthtmlgt
- Tag indicates the beginning and /end of an XHTML
document
30Document Tags - Header
- Header section, delimited by ltheadgt tags
- Provides extra information about the document
- Serves as a container for styles, global scripts,
etc. - The main tags used in this section are
- lttitlegt - specifies the document title
- ltmetagt - provides information to search engines
- ltstylegt - declares general local styles for the
document - ltscriptgt - declares any scripting information
31Meta Tags
- Web pages are designed for surfers and surf
engines - The ltmetagt tag increases the chances of page
indexing - Meta data refers to data about XHTML document
rather than the document content - Browsers do not render meta data
- Search engines use it for indexing and ranking
the page hits in a given search - Some attributes of this tag are name, content,
http-equiv, etc.
32Meta Tags
- Most often the meta element is used to provide
information that is relevant to browsers or
search engines like describing the content of
your document. - ltmeta namekeywords contentopen, source, PHP,
programming, code /gt - When a search engine indexes the page, it
includes the extra information -gt open, source,
etc. - It provides these keywords to search agents
requesting them
33Amazons Meta Tags
- ltmeta name"description" content"Low prices on
digital cameras, MP3, LCD TVs, books, music,
DVDs, video games, software, home garden and
much, much more. Free delivery on orders over
15." /gt - ltmeta name"keywords" content"digital camera,
LCD TV, books, DVD, low prices, video games, pc
games, software, electronics, home, garden,
video, amazon" /gt
34META
- Specify information about a document
- Attribute name
- Identifies the type of meta element
- keywords ( name keywords )
- Provides search engines with a list of words that
describe a page - description ( name description )
- Provides a description of a site
- Attribute content
- Provides the information search engine use to
catalog pages
35Sample XHTML Document Structure
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-strict.
dtd"gt - ltHTMLgt
- ltHEADgt
- ltTITLEgt New Document lt/TITLEgt
- ltMETA NAME"Author" CONTENT""gt
- ltMETA NAME"Keywords" CONTENT""gt
- ltMETA NAME"Description" CONTENT""gt
- lt/HEADgt
- ltBODYgt
- webpage content goes here!
- lt/BODYgt
- lt/HTMLgt
36 37(No Transcript)
38Minimal XHTML Document
- lt!DOCTYPE .gtlthtmlgt
- ltheadgt .. lt/headgt
- ltbodygt
- ltpgt
- .
- lt/pgt lt/bodygtlt/htmlgt
39XHTML Document Example
- lt?xml version1.0?gt
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Transitional//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-trans
itional.dtd"gt - lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
- ltheadgt
- lttitlegt Introduction to XHTMLlt/titlegt
- lt/headgt
- ltbodygt
- ltstronggt Course Name lt/stronggt
Introduction to XHTML ltbr /gt - ltstronggt Course Number lt/stronggt CS 112
ltbr /gt - ltstronggt Instructor lt/stronggt T. Perdue
ltbr /gt - ltstronggt Meeting Time lt/stronggt
Wednesday, 530pm730pm ltbr /gt - ltp /gt
- ltstronggt Course Description lt/stronggt This
course covers the basics - of how to write XHTML Web documents.
- ltp /gt
- ltstronggt Prerequsites lt/stronggt
- ltulgt
- ltligt CS 101Introduction to Computers
lt/ligt
40XHTML Document Example
41Using TextPad
TextPad is an editor that allows you to type
text. Can be used to create web pages
View in Web browser
file name
42View in browser
43Validating your pages
- XHTML shouldnt contain any deprecated (old and
out of date) tags. - Needs to be well formed (see slide 25)
- Needs to reference a DTD (DOCTYPE)(Document Type
Definition) - Prefers that character encoding is declared (for
transitional is required for strict) - Validate documents online at the W3Cs Validator
website http//validator.w3.org
44Validating your pages
Choose File Upload
Browse to find file
Then click here
Get this screen if code is valid
45Validating XHTML Documents
- Valid documents must be well-formed and adhere to
the rules of a DTD - XHTML Transitional
- lt!DOCTYPE html
- PUBLIC "-//W3C//DTD XHTML 1.0
Transitional//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-trans
itional.dtd"gt - XHTML Frameset
- lt!DOCTYPE html
- PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN"
- "http//www.w3.org/TR/xhtml1/DTD/xhtml1-frame
set.dtd"gt - XHTML Strict
- lt!DOCTYPE html
- PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
- "http//www.w3.org/TR/xhtml1/DTD/xhtml1-stric
t.dtd"gt
46Well-Formed XHTML Documents
- XHTML documents must contain the root element
lthtmlgt - All elements must have a start and end tag, or
must be an empty element - Elements must be nested properly
- All attributes must have a value
- Attributes must be placed in the start tag
- Element names are case sensitive
47 Class Activity 1
- Type the following xhtml code in Text pad,
validate it and then view it in a browser -
- lthtmlgt ltheadgt
- lttitlegtThe First Page in these noteslt/titlegt
- lt/headgt
- ltbodygt lth1gtYour text goes here or possibly
imageslt/h1gt - ltpgtltstronggt Or it could go herelt/stronggtlt/pgt
- lt/bodygt
- lt/htmlgt
48 Class Activity 1
- Now edit the code to look like this and validate
it and then view in a browser - lt?xml version1.0?gt
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Transitional//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-tran
sitional.dtd"gt - lthtml xmlnshttp//www.w3.org/1999/xhtml gt
- ltheadgt
- ltmeta http-equiv"Content-Type"
content"text/html charsetISO-8859-1 /gt - lttitlegtThe First Page in these noteslt/titlegt
- lt/headgt
- ltbodygt lth1gtYour text goes here or possibly
imageslt/h1gt - ltpgtltstronggt Or it could go herelt/stronggtlt/pgt
- lt/bodygt
- lt/htmlgt
49 50XHTML Tags Attributes
- The following slides do not contain a complete
list of available tags and attributes for XHTML - Refer to the web sitehttp//www.w3schools.com/xht
ml/default.asp - To access a full list of the standards associated
with XHTML
51Structure of XHTML Documents
- Documents consist of three parts
- Document Prolog
- Header
- Body
- 1 lt?xml version1.0?gt
- 2 lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-stric
t.dtd"gt - 3 lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
- 4 ltheadgt
- 5 lttitlegtStrict XHTML Documentlt/titlegt
- 6 lt/headgt
- 7 ltbodygt
- 8 lt!-- Body of document goes here --gt
- 9 lt/bodygt
- 10 lt/htmlgt
1 lt?xml version1.0?gt 2 lt!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Strict//EN"
"http//www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd
"gt 3 lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
4 ltheadgt 5 lttitlegtStrict XHTML
Documentlt/titlegt 6 lt/headgt 7 ltbodygt 8
lt!-- Body of document goes here --gt 9
lt/bodygt 10 lt/htmlgt
Root Element
52Document Framework Elements
- The lthtmlgt element
- This is the root element for an XHTML document
and must be present in every XHTML document - The header and body elements are contained within
the root lthtmlgt element - Attributes xmlnshttp//www.w3.org/1999/xhtml
(Declares a namespace for custom tags in an HTML
document.) - The ltheadgt element
- Contains header elements that contain data used
primarily by programs such as search engines - Elements that can be contained within the ltheadgt
element - lttitlegt - Title of the document
- ltbasegt - Base URL of the document
- ltlinkgt - Defines document relationship to other
documents - ltmetagt - Contains information about document such
as keywords, author information and content
type - ltscriptgt - Defines link to scripts used in the
document - ltstylegt - Defines links to style sheets used in
the document
53Document Framework Elements (cont.)
- The ltbodygt element
- This element encompasses the content of the
document - Style attributes available with XHTML
Transitional and Frameset - bgcolor sets the background color for the
document - text sets the color for text in the document
- link sets the color for hyperlinks
- vlink sets the color for hyperlinks that have
been clicked on - alink sets the color for active hyperlink
- NOTE Formatting attributes not included in the
XHTML Strict 1.0 specification and will not be
included in future versions of XHTML. The
formatting styles provided by these attributes
are being replaced by style sheet properties.
54Basic Formatting Elements
- Block Level Elements
- Used to describe blocks of content and to label
the main content headings - Character Level Elements
- Presentational Elements Used to define how text
should be displayed - Logical Elements Used to define the meaning of
the text style
55Block Level Elements
- ltpgtlt/pgt - Paragraph element
- ltpgt This is a paragraph lt/pgt
- ltbr /gt - Line break (empty element)
- This is a line break ltbr /gt
- lth1gtlt/h1gt to lth6gtlt/h6gt - Heading elements
- lth1gtThis is the largest headinglt/h1gt
- lth6gtThis is the smallest headinglt/h6gt
- lthr /gt - Horizontal rule (empty element)
- This is a horizontal rule lthr /gt
- ltdivgtlt/divgt - Section divider
- ltdivgtThis is a section dividerlt/divgt
56Block Level Elements XHTML Code
- lt?xml version1.0?gt
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-stric
t.dtd"gt - lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
- ltheadgt
- lttitlegtXHTML Block-level Elementslt/titlegt
- lt/headgt
- ltbodygt
- ltpgt This is a paragraph about African Gray
parrots. The African Gray is - one of the most popular pet birds of
the parrot family. It is known - for its intellegence and is one of the
best talkers of all domestic - birds. This parrot is native to Africa
and can live to be almost 70 - years old.lt/pgt
- ltpgt This is also a paragraph about African
Gray parrots. Here is some - additional information about the
African Gray parrot separated by - line breaks (break here) ltbr /gtThe
African Gray parrot is about 15 - inches long and (break here) ltbr /gtHas
a wing span of about 20 - inches.lt/pgt
- lthr /gt
57Block Level Elements Web Browser
58Presentational Formatting Elements
- ltbgtlt/bgt - Bold font style
- ltbgtThis text is boldlt/bgt
- ltbiggtlt/biggt - Increases the current font size
- ltbiggtThis text is larger than the current
fontltbiggt - ltigtlt/igt - Italic font style
- ltigtThis text is in italic fontlt/igt
- ltsmallgtlt/smallgt - Decreases the current font
size - ltsmallgtThis text is smaller than the current
fontlt/smallgt - ltsubgtlt/subgt - Subscript text
- ltsubgtThis text is subscriptlt/subgt
- ltsupgtlt/supgt - Superscripted text
- ltsupgtThis text is superscriptlt/supgt
59Presentational Formatting Elements XHTML Code
- lt?xml version1.0?gt
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-stric
t.dtd"gt - lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
- ltheadgt
- lttitlegtXHTML Presentational Text Formatting
Elementslt/titlegt - lt/headgt
- ltbodygt
- ltpgt
- This text is formatted in ltbgtboldlt/bgt
- lt/pgt
- ltpgt
- This text is formatted in ltigtitalicslt/igt
- lt/pgt
- ltpgt
- See how ltbiggtthe big elementlt/biggt
increases the current font size - and how ltsmallgtthe small
elementlt/smallgtdecreases it. - lt/pgt
- ltpgt
60Presentational Formatting Elements Web browser
61Presentation Controls
- All tags have associated attributes but many
attributes ( tags) have been deprecated with the
move from HTML to XHTML - XHTML uses Cascading Style Sheets (CSS) to format
the content rather that embedding the formatting
code within the XHTML code(these will be covered
later in the course) - Transitional XHTML still supports these
attributes and they can be used for the first few
tutorials until CSS has been covered. - The background colour can be set with the ltbodygt
tag (deprecated in XHTML) ltbody bgcolor
FFFF00gt (sets the colour to yellow) - Font attributes can be set with ltfont color
0066CC face Timesgt(Both the tag and the
attributes have been deprecated) - Text can also be aligned (deprecated) either with
ltpgtorlth1gt etcltp align centergt or lth3 align
rightgt
62Logical Formatting Elements
- ltcitegtlt/citegt - Formats citation text
- ltcitegtThis text is boldlt/citegt
- ltcodegtlt/codegt - Formats computer code text
- ltcodegtThis is computer code textlt/codegt
- ltemgtlt/emgt - Emphasis formatting in most
browsers, this is italic text - ltemgtThis is emphasis text - italicslt/emgt
- ltstronggtlt/stronggt - Emphasis formatting in
most browsers, bold text - ltstronggtThis is emphasis text - boldlt/stronggt
63Logical Formatting Elements- XHTML Code
- lt?xml version1.0?gt
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-stric
t.dtd"gt - lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
- ltheadgt
- lttitlegtXHTML Logical Text Formatting
Elementslt/titlegt - lt/headgt
- ltbodygt
- ltpgt
- Following is a citation ltbr /gt
- ltcitegt
- Four score and seven years ago, our fathers
brought forth upon this continent a new nation - conceived in liberty, and dedicated to the
proposition that all men are created equal. - lt/citegt
- lt/pgt
- ltpgt
- Following is a block of code ltbr /gt
- ltcodegt
- while (x lt 10) ltbr /gt
64Logical Formatting Elements- Web browser
65 66XHTML Lists
List Type Element Item Element
Ordered List ltolgtlt/olgt ltligtlt/ligt
Unordered List ltulgtlt/ulgt ltligtlt/ligt
Definition List ltdlgtlt/dlgt ltdtgtlt/dtgt ltddgtlt/ddgt
67Ordered list - code
68Ordered list web browser
69Unordered list - code
70Unordered list web browser
71XHML Lists Nesting Lists
- A nested list is a list of items which is
contained within another list - Lists can be nested any number of times
- List types can be mixed when nesting. For
example, an ordered list of items can be nested
within an unordered list - The open and close tags of the nested list must
be completely contained within one item of the
outer list
72Nested list - code
73Nested list web browser
74 Class Activity 2
- Create the following web page using Textpad,
validate your code and then view in a browser.
heading 1
heading 2
paragraph
line break
horizontal rule
75 Class Activity 2
- Create the following web page using Textpad,
validate your code and then view in a browser. -
heading 1
Heading 2
ordered list
unordered list
76 77XHTML Tables
- XHTML tables are sets of elements used to format
content, or even an entire document, into rows
and columns - Tables can contain any type of content, including
text, links, images, and multimedia - Tables in XHTML work much the way they do in a
spreadsheet or word processing application and
resemble a grid - Tables can be used to format blocks of content or
they can also be used to providing formatting for
an entire document
78Table Elements
- lttablegt - Encloses the rest of the table
elements - lttrgt - Table Row Used to designate the
beginning and ending of a row of data - ltthgt - Table Heading Used to label the heading
cells in a table row - lttdgt - Table Data Used to label data cells in a
table row - ltcaptiongt - Optional element. Used to describe
the data in the table. -
79Table- code
80Table- web browser
This output isnt very easy to read. It would
be easier to read if it had a border and the
columns were wider. To vary the output from the
default you need to set attributes
81lttablegt Common Element Attributes
- Name Description and Values
- width Sets the width of the table.
- Values Percentage or pixels
- border Sets the width of the border around the
table. Values A value of 0 makes the border
invisible. An integer value greater than 0 will
result in a border of that number of pixels. - cellpadding Sets the amount of space between
the border of the table cell and the data
contained in the cell. - Values Percentage or pixels
- cellspacing Sets the amount of space between
cells. - Values Percentage or pixels
-
82Table code with attributes
border width attribute set
Attributes have a name and a value the value is
written in double quotes in lowercase
83Table web browser
84lttdgt and ltthgt Element Attributes
- Name Description and Values
-
- align Horizontal alignment of data in a cell
- Values left, center, right, justified
- valign Vertical alignment of data in a cell
- Values top, middle, bottom
-
- rowspan Number of rows a cell span
- Values integer greater than 1 and less than or
equal to the total number of rows in the table - colspan Number of columns a cell span
- Values integer greater than 1 and less than or
equal to the total number of columns in the table - abbr Used for an abbreviated version of the
content of the cell - axis Used to assign a cell to a category group
- headers List of cells that provide header
information for the current cell based on the
values of the id
85lttrgt Element Attributes
- Name Description and Values
-
- align Horizontal alignment of data in all cells
in a row - Values left, center, right, justified
- valign Vertical alignment of data in all cells in
a row - Values top, middle, bottom
86 Class Activity 3
- Create the following web page using Textpad,
validate your code and then view in a browser.
Now modify your code so the web page looks like
this
87 Class Activity 3
- Create the following web page using Textpad,
validate your code and then view in a browser. -
88 Class Activity 3
- Create the following web page using Textpad,
validate your code and then view in a browser. -
89 90Image File Formats
- Three primary formats for Web images
- GIF Graphics Interchange Format
- The GIF format supports 256 colors and is a good
format for small non-photographic images like
icons and buttons - JPEG - Joint Photographic Experts Group
- JPEG is a compression technique that is used to
reduce large file sizes for high quality images,
like photographs - PNG - Portable Network Graphics
- PNG was originally developed to replace the GIF
format. The biggest difference between PNG and
GIF is that PNG supports more than 256 colors - The next slide will demonstrate the differences
in image quality and file sizes for these 3
formats. Notice that the GIF file is much more
grainy than the JPEG and PNG files. This is due
to the restriction to only 256 colors.
91Image File Formats Example
Original file Windows Bitmap file Stage.bmp
File Size 351k
GIF Format Stage.gif File size 13k
PNG Format Stage.png File size 164k
JPEG Format Stage.jpg File size 28k
92The ltimggt element
- The ltimggt element is an empty element
- The two required attributes are
- src Defines the path to the image file - can be
an absolute or relative path - alt Defines alternate text for the image file
that will display in place of the image if the
client can not display images - ltimg src"myimage.gif" alt"Alternate text" /gt
93Image- code
This code assumes that an image named forest.jpg
is stored in the same directory as the html file
94Image- Web browser
95File organisation
- The previous example assumes the image file is in
the same folder as html file - But web sites can get complicated and they are
much easier to manage if your files are organised
into folders - Eg
- if your images are in a separate folder - then
the path would look like this in the previous
exampleltimg src../images/forest.jpg
alttrees /gt
96 Class Activity 4
Download the images from online
- Create the following web page using Textpad,
validate your code and then view in a browser.
mountains.png
beach.jpg
97 Class Activity 4- Challenge
- Create the following web page using Textpad,
validate your code and then view in a browser.
Hint Use a table without borders and investigate
the attribute colspan for the heading
98 99Link Types
- Link to other pages within site
- Link to other sites
- Link to a named place within the same page
- Link to create an email message.
100Creating XHTML Links
- The anchor element - ltagt
- Requires the user to perform an action in order
to activate the link. Usually this is clicking
on the linked text or image - The href attribute defines the file to be linked
to - lta hrefhttp//chughes.com/index.htmlgtThis is a
linklt/agt
101Creating XHTML Links
- Relative vs. Absolute URLs
- Relative links are used to link to documents that
reside on the same Web server, so the protocol
and domain name reference can be omitted from the
URL - lta hrefnewpage.htmlgtClick Herelt/agt
- Absolute links are used to link to documents that
reside on different Web servers and must contain
the complete URL - lta hrefhttp//chughes.com/newpage.htmlgtClick
Herelt/agt
102Linking With the ltimggt Element
- To use the ltimggt element as a link
- Embed the ltimggt element within an ltagt element
- lta hrefnewpage.htmlgtltimg srcmyimage.gif
altClick on this image /gtlt/agt - By default, web browsers place a blue border
around the image to identify it as a clickable
object - To remove the blue border around the image, use a
style definition. This is usually done in a
cascading style sheet.(CSS) This will be covered
later in the course. -
103XHTML Links code
- lt?xml version1.0?gt
- lt!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0
Strict//EN" - "http//www.w3.org/TR/xhtml1/DTD/xhtml1-stric
t.dtd"gt - lthtml xmlnshttp//www.w3.org/1999/xhtmlgt
- ltheadgt
- lttitlegtLink Examples in XHTMLlt/titlegt
- lt/headgt
- ltbodygt
- ltpgt Here are some examples of links in XHTML
lt/pgt - ltpgtlta hrefhttp//chughes.com/newpage.htmlgtThi
s is an absolute link to a new
pagelt/agtlt/pgt - ltpgtlta hrefnewpage.htmlgtThis is a relative
link to a new pagelt/agtlt/pgt - ltpgtlta hrefnewpage.htmlgtltimg srcbutton.gif
altThis image is a - clickable buttongtlt/agtlt/pgt
- ltpgtlta hrefmailtocheryl_at_chughes.comgtThis is
link that launches an - email messagelt/agtlt/pgt
- lt/bodygt
- lt/htmlgt
104XHTML Links Web Browser
105Linking within a single document
- Links can be created to reference different
sections of a single document using internal
links and anchors - Use an anchor to mark a section in the document
where you would like to link to -
- lta namefootnotegtFootnotelt/agt
- Use an internal link to reference the anchored
section. Internal links begin with a
character -
- lta hreffootnotegtLink to footnotelt/agt
- When the user clicks on the internal link, they
will be directed to the section referenced by the
anchor
106Linking within a single document - code
internal link has in front of name
Named anchor
107Linking within a single document web browser
internal links will jump to where the named is
anchor is
108 Class Activity 5
- Create the following web page using Textpad,
validate your code and then view in a browser.
Links to Act3_Q1.html
Links to Act4_Q1.html
109 XHTML Forms
110Overview of XHTML Forms
- Web forms give Website owners the ability to
receive information from their users or to allow
users to personalize the Website - A Web form can contain many types of input
elements - Text boxes
- Password boxes
- Buttons
- Checkboxes
- Pull-down menus
- Form input values are processed by a program on
the Web server and usually send another XHTML
page back to the Web browser with either a set of
results based on the users input, or a
confirmation page - Forms can be located anywhere in the body of an
XHTML document
111The ltformgt Element
- The ltformgt - element contains all of the input
elements of the form - Attributes
- action This attribute is required and provides
the path to the program that will process the
form data when the user submits the form - Examples
- ltform action/cgi-bin/process.cgigt
- ltform actionhttp//www.grahamm.com/cgi-bin/proce
ss.cgigt - ltform actionmailtograhamm_at_chisholm.vic.edu.augt
- method This attribute tells the web server how
to process the data - Values
- get This is the default value and will
automatically assign this value if the method
attribute is not present in the ltformgt element.
This method appends the form input data to the
end of a URL. - The following two ltformgt start tags are the
same - ltform action/cgi-bin/process.cgi methodgetgt
- ltform action/cgi-bin/process.cgigt
- post This value tells the processing program to
send the form data to the server as regular input
data. Nothing will be appended to the URL
112Text Input Elements
- There are three types of text input elements
which are empty elements - Text ltinput typetext /gt Allows users to
enter text - Password ltinput typepassword /gt Allows users
to enter text which is not visible to others.
The characters are entered and appear only as the
character. - WARNING even though the value is hidden while
it is being typed, the value is sent to the
server in text form - File ltinput typefile /gt Allows users to
Browse their computer in order to send a file to
the Web server
113Text input elements - attributes
- The following attributes can be used with text
input elements - maxlength - Maximum number of characters allowed
for input - name - Used to identify the input field
- size - Defines the size of the input field in
characters. If this is smaller than the
maxlength attribute, the field will scroll. - type - Defines the type of input (text, password,
or file for text input fields) - disabled - Disables the field for user input. The
value of a disabled field will not
be sent to the processing program - readonly - Makes the content of the text field
unchangable. The value of this field will be
sent to the processing program - value - Sets a default value
- onselect - For use with scripts. An event handle
that specifies an action to be performed when
the field is selected - onchange - For use with scripts. An event handle
that specifies an action to be performed when
the content of the field has been changed
114Selection Form Elements
- The selection form elements allow the user to
select one or many choices from a list - There are 3 types of selection elements
- Checkboxes ltinput typecheckbox /gt
- Radio buttons ltinput typeradio /gt
- Drop-down lists ltselectgtlt/selectgt
- Using selection elements
- Checkboxes - used for lists where the user can
choose one or more selections from a list
of options. Each item in a checkbox group
can be checked or unchecked. - Radio Buttons used for lists which allow the
user to choose only one item in the
list - Drop-down lists - The list appears in a
scrollable box. These are usually used for
long lists of items. - Each item is listed in a separate ltoptiongt
element
115Completing the Form
- Once a user has completed the form, the data must
be sent to the server to be processed - The XHTML language provides a means to submit the
form using the program that is specified in the
action attribute of the ltformgt element by
assigning the value of submit to the type
attribute for the ltinput /gt element - ltinput typesubmit /gt
- XHTML also gives users an ability to clear the
form and reset the default values by assigning
the value of reset to the type attribute for
the ltinput /gt element - ltinput typereset /gt
- The value attribute can be set to assign names to
either of these buttons. If no value is set, then
the computer will assign default text
116Form Example code
Open ltformgt element
Checkbox group for accounts
Radio group for emp
Select group for branch
submit button
close ltformgt element
117Form Example Web Browser
118 Class Activity 6
- Create the following web page using Textpad,
validate your code and then view in a browser.
119 Class Activity 6
- Modify the form created in Question 1 and use a
table to set the elements out more neatly, like
in the example below
120 Lab 1
- A web site is a collection of web pages that link
together.You are now going to create the
following web site that uses tables, links,
images, lists and forms.The site consists of
four pages - welcome.html
- baked_pears.html
- pumpkin_creme_brulee.html
- contact_me.html
121 Lab 1
To complete this table you will need to
investigate the attributesrowspan colspan
Links to baked_pears.html
Links to pumpkin_creme_brulee.html
recipe.jpg
Links to contact_me.html
welcome.html
122 Lab 1
back_button.jpg links back to welcome.html
pumpkin_creme_brulee.jpg
pumpkin_creme_brulee.html
123 Lab 1
back_button.jpg links back to welcome.html
Challenge Work out how to add a fraction
degree symbol
baked_pears.jpg
baked_pears.html
124 Lab 1
back_button.jpg links back to welcome.html
contact_me.html
125Summary
- In this section you learnt how to add the
following elements to a web page - Headings
- Lists
- Tables
- Images
- Links
- Forms
- We didnt cover any formatting like different
fonts or colors or alignment or removing
borders.This is because most of those attributes
and tags are deprecated and formatting is
primarily done using cascading style sheets (CSS)
this is covered in the next section.