ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
4. Internet Programming
1
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Reference
H.M. Deitel, P.J. Deitel and T.R. Nieto, Internet
and World Wide Web: How to Program, Prentice
Hall, 2002
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Web site development
To develop a Web site, three steps:
1. Obtain the appropriate equipment
Web Server – hardware and software
2. Register the Web Server to an Internet
Service Provider (ISP)
Obtain the IP address and DNS address
3. Develop the contents
Internet Programming
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Internet Programming
Web service is a kind of client / server process
Need interaction between client and server
Programming for providing Web service can
also be divided into
– Client-side programming: to define the operation to
be performed on the client’s machine
– Server-side programming: to define the operation to
be performed on the server
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Internet
Database Web Server Web Client
Server-side Programming Client-side Programming
Skills that are often required: Skills that are often required:
• CGI • XHTML
• PHP • Javascript
• ASP • Java
• Perl • Dreamweaver
• Java Servlet, … • Flash
• SMIL, XML …
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
4.1 XHTML – Extensible HyperText
MarkUp Language
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
Web programming using XHTML
Nowadays, there are many tools that help to
develop Web page
– Dreamweaver, Visual studio
Provide sophisticated tools to allow Web page
developed in a graphical manner
Finally, the job of these tools is to convert the
user design to XHTML code
Understanding of XHTML allows us
– fine tuning the codes generated by these tools
– understand the source of a Web page
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
What is XHTML?
Unlike procedural programming languages, e.g. C, C++, XHTML
is a markup language that specifies the format of document to be
seen in browser
XHTML has replaced the HTML as the primary means of
describing the Web page content
Become a World Wide Web Consortium (W3C) recommendation
– W3C is an industry consortium
– Seeks to promote standards for the evolution of the Web and
interoperability between WWW products by producing specifications and
reference software
Compared with HTML, XHTML provides more robust, richer and
extensible features
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
Features of XHTML
Platform independent
– The same piece of code can give the same display in Mac,
Linux and Windows
Text-based
– Program is written with ASCII characters
– Can be written using a text editor, such as notepad
An XHTML file must have an extension of .html or .htm
Information is generally enclosed inside paired tags
– E.g. <html> … </html>
– There are many tags in XHTML. They specify different
information required to display the Web page content
9 start tag end tag (with a /)
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
Basic Structure of XHTML
<html>
<!-- This is a comment -->
<head>
<title>
This is title, describing the content
</title>
</head>
<body>
This is body, main part of the page
</body>
</html>
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
useful
usefulforforvalidating
validatingthe
thecode
codetoto
see
seeififthey
theymeet
meetthe
thexhtml
xhtmlstandard
standard
<?xml version = "1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<!-- main.html --> comment
comment
<!-- Our first Web page -->
define
definethe
thenamespace
namespaceof
ofhtml
html
<html xmlns = "http://www.w3.org/1999/xhtml">
<head>
<title>Internet and WWW How to Program -
Welcome
</title>
</head> define
definethe
thetitle
titleof
ofthe
theweb
webpage
page
<body>
<p>Welcome to XHTML!</p>
</body>
</html> <p> - new paragraph Example
Example
11 <p> - new paragraph
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
See the title defined in head
That’s the content defined in body
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming - XHTML
An XHTML document can be divided into 2
sections
head section
– contains information of how the page is formatted
– e.g. <title> … </title> can be found in head section
to indicate the title of the Web page when it is
shown in browser
body section
– contains the actual page contents
– e.g. <p>Welcome to XHTML!</p> shows a line of
text “Welcome to XHTML!” on the new paragraph
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Tags
Tags: case sensitive
– For XHTML, <center> is different from <CENTER>
– For HTML, it is case insensitive
Browse will not display information within tag that does
not understand
Tags: no precise positioning
Many start tags define attributes that provide additional
information
E.g. <html xmlns = "http://www.w3.org/1999/xhtml">
start tag attribute name attribute value
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Common Tags – Headers
Some text may be more important the others
XHTML provides six headers, called header elements,
for specifying the relative importance of information
– <h1> … </h1>, <h2> … </h2> to <h6> … </h6>
It is assumed the text in <h1> is more important than
that in <h2> and so on so forth
By default, the size of the text that is more important is
bigger
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
<html xmlns = "http://www.w3.org/1999/xhtml">
<head>
<title>Internet and WWW How to Program -
Headers</title>
</head>
<body> 66headers
headersare
areall
allused
used
to
toindicate
indicatethe
therelative
relative
<h1>Level 1 Header</h1>
importance
importanceof oftext
text
<h2>Level 2 header</h2>
<h3>Level 3 header</h3>
<h4>Level 4 header</h4>
<h5>Level 5 header</h5>
<h6>Level 6 header</h6>
</body>
</html>
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Text
Textunder
under<h1>
<h1>has
hasthe
thelargest
largestsize
size
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Meta Tag
HTML interacts with the search engines
through using meta tag
These
Thesewords
wordsare
arecompared
compared
with
withwords
wordsin
insearch
searchrequests
requests
<head>
<meta name=“keywords” content=“lecture notes, html,
form, feedback”>
<meta name=“description” content = “this web site
describes …”>
</head>
Description
Descriptionof
ofaapage
pageseen
seenon
onsearching
searching
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Linking Webpage
One of the most important XHTML features is
the hyperlink
– Link to another resources, such as web page,
image, etc.
Achieve by using the anchor tag <a>:
– To a web page:
<a href=“http://www.eie.polyu.edu.hk”>PolyU</a>
anchor
anchorattribute
attribute The
Thename
nameon onthe
theWeb
Web
page
pagethat
thatrepresents
representsthis
this
Value
Valueof
ofthe
theattribute:
attribute: link
link
19 The
Theaddress
addressof
ofthe
theWeb
Webpage
page
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
strong
strongtag
taglets
letsthe
thetext
textto
tobe
be
<body> displayed
displayedwith
withbold
boldfont
font
<h1>Here are my favorite Other
Othersimilar
similartags
tagsinclude
include
sites</h1> <u>
<u>underline
underlineand
and<em>
<em>italic
italic
<p><strong>Click a name to go to that page.
</strong></p>
Four
Fourlinks
linkscreate
create
<!-- Create four test hyperlinks -->
<p><a href = "http://www.polyu.edu.hk">PolyU</a></p>
<p><a href = "http://www.eie.polyu.edu.hk">EIE</a></p>
<p><a href = "http://www.eie.polyu.edu.hk/~enpklun">
Dr Daniel Lun's Home</a></p>
<p><a href = "http://www.eie.polyu.edu.hk/
~enpklun/ENG224/ENG224.htm">ENG224 Home page</a></p>
</body>
Don’t
Don’tintroduce
introducespaces
spacesbetween
between
20 different
differentparts
partsof
ofaaURL
URLaddress
address
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
This
Thisline
lineisisshown
shownwith
withaabold
boldfont
font
Four
Fourlinks
linksare
areincluded
included
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Linking Email Addresses
To a mail address:
<a href=“mailto:enpklun@polyu.edu.hk”> Email me
</a>
With a subject:
<a href=“mailto:enpklun@polyu.edu.hk?subject=title”>
Email me
</a>
Multiple recipients:
<a href=“mailto:address1,address2, address3”> Email me
</a>
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Linking Images
Background Image can be defined as an
attribute of the body tag:
<body background=“image.gif”>
To show an Image inside a page:
<img src=“image.gif” border=“0” height=“256”
width=“256” alt=“text description of the image”/>
We can create an image hyperlink
<a href=“page1.html”>
<img src=“image.gif” …/>
</a>
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Will
Willscale
scaleto
tothis
thissize
sizeto
todisplay
display
<body>
<p><img src = "xmlhtp.jpg"
height = "238“ width = "183"
alt = "XML How to Program book cover"/>
<img src = "jhtp.jpg"
height = "238" width = "183"
alt = "Java How to Program book cover"/>
</p>
</body>
empty
emptyelement:
element: jhtp.jpg
jhtp.jpgininfact
factcannot
cannotbebefound.
found.
do
donot
notmarkup
markuptext
text With
Withthethealt
altattribute,
attribute,the
thestatement
statement
isisdisplayed
displayedififthe
theimage
imageisisnot
notfound
found
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
“alt”
“alt”statement
statement(may
(maynot
not
display
displaythe
thesame
samefor
for
Netscape)
Netscape)
The
Theimage
imagedisplayed
displayedatatthe
the
specified
specifiedsize
size
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Color
2 ways to specify:
– Use hexadecimal numbers
– RGB format: FF: strongest, 00 weakest
#FF0000
#00FF00
#0000FF
– Use color names
Black, White, Red, Cyan, Green, Purple,
Magenta, Blue, Yellow, OrangeRed,
SpringGreen, BlueViolet, Gold,
DarkGoldenrod, Burlywood, …
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Color
Background color:
– <body bgcolor=“#00FF00”> … </body>
– <body bgcolor =“green”> … </body>
Text color, links, visited links and activated links:
– <body bgcolor =“white” text=“black” link=“purple”
vlink=“blue” alink=“yellow”>
Font color:
– <font color=“green”> … </font>
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Formatting Text
The format of displayed text can be changed by using
<font> … </font>
Attributes:
– Color:
– Size:
Relative: +1, +2, -3, …
Absolute: 10, 12, …
– Face:
Font used
Arial, Verdana, Helvetica, Times, …
Multiple fonts:
<font face="Arial, Helvetica, sans-serif">
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
background
backgroundcolor
colorisisyellow
yellow
<body bgcolor = “#ffff00”>
<p><font face="courier" color="green" size=“24”>
This is a test.</font> horizontal ruler
<hr /> horizontal ruler
<font face="times" color="red" >
This is a test.</font> the
thebackslash
backslashisisonlyonly
</p> to improve readability
<p> to improve readability
<font face="arial" color="red" size=“+1”>
See
Seethe
the This is a test.</font>
difference
difference <br />
between <font face="times" color="#ff00ff" size=“+2”>
between This is a test.</font>
<p> and
<p> and </p>
<br>
<br> <p align = center><font face="courier" size=“+3”>
This is a test.</font>
</p> the
the text
text isisplaced
placed atatthe
the center
center
29 </body>
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
size
size ==24
24
default
defaultsize
size
size
size==+1,
+1,+2,
+2,+3
+3
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Lists
Unordered list
– a list that does not order its items by letter or number
– <ul> … </ul> creates a list where each item begins
with a bullet
– List items: <li> … </li>
– For example
<ul>
<li>Apple</li>
<li>Orange</li>
<li>Banana</li>
</ul>
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Lists
Ordered list
– List that order their items by letter
or number
– <ol type=“style”> … </ol>
When style equals to
1: decimal, 1, 2, 3, …
I: uppercase Roman, I, II, III, …
i: lowercase Roman, i, ii, iii, …
A: uppercase Latin, A, B, C, …
a: lowercase Latin, a, b, c, …
– List items: <li> … </li>
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Table
Organize data into rows and columns
Table caption
Table header
Table body
Table footer
33 Table border
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
<table attribute=“value”> … </table>
Attribute examples:
– border=“1” the larger the number, the thicker is the border.
“0” means no border
– align=“center” the table is aligned at the center of the
browser
– width=“60%” to set the table width to 60% of the browser’s
width
Caption of the table: <caption> … </caption>
Insert a table row: <tr> … </tr>
The head, body and foot sections are defined by
<thead> … </thead>
<tbody> … </tbody>
34 <tfoot> … </tfoot>
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
<table border = "1" width = "40%" align = left
summary = "This table provides information about
the price of fruit">
<caption><strong>Price of Fruit</strong></caption>
<thead>
<tr> <!-- <tr> inserts a table row -->
<th>Fruit</th> <!-- insert a heading cell -->
<th>Price</th>
</tr> The
Theuse
useof
ofth
thtag
tag
</thead> defines
definesthe
the
The
Thetrtrtag
taginsert
insert content
contentof
ofheader
header
<tbody> aanew
newrowrow or
<tr>
orfooter
footercells
cells
<td>Apple</td> <!-- insert a data cell -->
<td>$0.25</td>
35 </tr>
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
<tr> <tfoot>
<td>Orange</td> <tr>
<td>$0.50</td> <th>Total</th>
</tr> <th>$3.75</th>
<tr> </tr>
<td>Banana</td> </tfoot>
<td>$1.00</td> </table>
</tr>
<tr>
<td>Pineapple</td>
<td>$2.00</td> The
Theuse
useof ofth
thtag
tag
</tr>
The use of td tag defines
defines the
the
</tbody> The use of td tag content of header
defines
definesthe
the content of header
content or
orfooter
footercells
cells
contentof
ofbody
body
36 cells
cells
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Col span and Row span
colspan and rowspan allow merging
columns/rows
– <colspan=“number”>
data cell spans more than one column
– <rowspan=“number”>
data cell spans more than one row
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
<table border=“1” width=“60%”>
<caption> Average Grades </caption>
<tr>
<th colspan=“4”> Report </th> first
firstrow
row
</tr>
<tr>
<th> </th> <th> 2000 </th> <th> 2001 </th>
<th> 2002 </th>
</tr> 2nd
2ndrowrow
<tr>
<td> Maths </td> <td> A </td> <td rowspan=“2”
valign=“center”> B </td> <td> C </td>
</tr>
<tr> vertical
verticalalignment
alignment 3rd
3rdrow
row
<td> English </td> <td> C </td> <td> A </td>
</tr>
</table> 4th
4throw
row
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
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ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Forms
When browsing
web sites, users
often need to
provide information
such as email
address, search
keywords, etc
Forms allows user
to input information
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
App CGI
Internet
Web Server Web Client
1
www.abc.com/form.htm
2
www.abc.com
method = post or get
3
action = program name
(script) in server to
receive the data
Name = ???
42 and others
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
A form element is inserted into a web page by the
<form> tag
<form method = “value1” action = “value2”> … </form>
Attributes:
– method = “post” or “get”
Indicates the way the Web server will organize and
send you the form output
post: causes changes to server data, e.g., update
a database
get: does not cause any changes in server-side
data, e.g., make a database request
– action = “”
Path to script, e.g., CGI
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
use script
scriptthat
thatwill
willbe
becalled
calledto
to
usepost
postmethod
method
execute
executeininthe
theserver
server
<form method = “post” action = “/cgi-bin/formmail”>
<input type=“radio” name=“size” value=“large”
checked=“checked”/> large
<input type=“radio” name=“size” value=“medium”/>
medium
<input type=“radio” name=“size” value=“small”/>
small
</form>
Only
Onlythe
theradio
radio
button
buttonof
oflarge
largeisis
checked
checked
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Forms
Elements inside a form are introduced by the
<input> tag
<input>
– type=“hidden” name=“variable name”
value=“value that sends to the server”
– type =“text” name=“” value =“” size=“25”
– type =“submit” value =“”
– type =“reset” value =“”
– type =“checkbox” value =“” name=“”
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Thing
Thingthat
thatsends
sendsback
backto
toserver
server
Form example I
<input type=“checkbox” name=“things”
value=“ham”/> Ham
<input type=“checkbox” name=“things”
value=“sweetcorn”/> Sweet Corn Indicate
Indicateall
all55
<input type=“checkbox” name=“things” checkboxes
checkboxes
value=“mushroom”/> Mushroom belong
belongtotothe
the
<input type=“checkbox” name=“things” same
samegroup
group
value=“chicken”/> Chicken
<input type=“checkbox” name=“things”
value=“peas”/> Peas
The
Thewords
wordsshow
showon
onscreen
screen
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INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Form example II
Data
Datathat
thatwould
wouldsend
sendto
to
server
serverbut
butdo
donot
notdisplay
displayon
on
screen
screen
<input type="hidden" name=“title" value="Feedback" />
<p><label>Name:
<input type= "text" name= "name" size="25"
maxlength="30"/>
</label>
send
sendthe
theinput
inputthe
thetextbox
textboxto
toserver
server
</p>
<input type= "submit" value="Submit your entries"/>
<input type= "reset" value="Clear Your Entries"/>
47 clear
clearthe
thecontent
contentof
oftextbox
textbox
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Form example III
Masked
Maskedby
byasterisk
asterisk
Space
Spaceisiscounted
countedhere
here
<p><label>Comments:<br />
<textarea name= "comments" rows="4" cols="36">
Enter your comments here.
</textarea> </label></p>
<p><label>Please input your password:
<input name= "secret" type="password" size="25"/>
</label></p>
<input type= "submit" value="Submit Your Entries"/>
48<input type= "reset" value="Clear Your Entries"/>
ENG224
INFORMATION TECHNOLOGY – Part I
4. Internet Programming
Form example IV
The
The“selected”
“selected”value
valuehere
here
mean
meanAmazing
Amazingisisselected
selected
default
defaultvalue
value
<p><label>Rate our site:
<select name= "rating">
<option value=“Amazing”
selected="selected">Amazing</option>
<option value=“3”>3</option>
<option value=“2”>2</option> Change
Changeto
todefault
default
<option value=“1”>1</option> value
valuewhen
whenreset
reset
<option value=“0”>0</option>
</select></p>
<input type= "submit" value="Submit Your Entries"/>
<input type= "reset" value="Clear Your Entries"/>
49
