The document provides a comprehensive overview of web forms, detailing their structure, components, and the data flow between users and servers. It covers the construction of forms using HTML, including tags like <form>, <input>, <select>, and the use of client-side scripting for validation. Additionally, it highlights the importance of server-side processing for handling user inputs and improving form accessibility.

1. EASING
INTO WEB
DEVELOPMENT
4.
4 FORMS

2. 1 INTRODUCTION
2 HTML
3 TABLES
4 FORMS
5 HTTP
6 CSS
7 CSS FRAMEWORKS
8 DIGITAL MEDIA
2 9 USABILITY

3. What is a Form?
3
 A form is a way to pass information from a web
browser to a program on a Web server.
 Forms thus provide two-way communication: from
the server to the user, and from the user to the
,
server.

4. Form data – where does it go?
4
 The data that is input into a f
form is sent back to the
server as a series of name=value pairs separated
by
b ampersands.d
 E.g. firstname=karl&lastname=marx&price=1.59
 This information is URL encoded, but it is certainly
f d d
not encypted.
 E.g. name=karl%20marx
 HTTPS encypts this information.
 This data is sent either via the url or within the HTTP
header.

5. Three Parts of a Form
5
1. The form that the user sees and enters data into.
 This is constructed with HTML tags
2. A script for validating the user's entry (optional).
 This runs on the browser
 written in Javascript
3. A program that processes the user data.
p g p
 This resides on the server.
 Typically uses CGI-Perl, ASP, PHP, ASP.NET or some other
yp y , , ,
server-side scripting/programming technology & language.
 Also should validate the user’s entry

6. 1. Building the Form in HTML
6
 Two
T parts
 <form> ... </form> tag
 form elements
 <input>
 <select> and <option>
 <textarea>
 <label>, <legend>, and <fieldset>

7. Example
7
<h2>on-line wine buyer</h2>
<form>
guest name:
<input type="text" name="guest" size="40"/><br/>
e mail:
e-mail:
<input type="text" name="email"/><br/>
color:
<input type="radio" name="winecolor" value="w"/>white
<input type="radio" name="winecolor" value="r"/>red
<input t
<i t type="radio" name="winecolor" value="o"/>rose
" di " " i l " l " "/>
<p>price:
<select name="price">
<option>choose a price</option>
<option>below $10</option>
<option>between $10 and $20</option>
<option>above $20</option>
</select>
</p>
<p><input type="submit"/></p>
type submit /></p>
</form>

8. <form> Tag
8
 While
Whil you can hhave several <form> ... </f
l <f > </form> in a page,
>i
they cannot be nested
 attributes
 id=
 id of the form (only necessary if more than one form in page)
 action=
ti
 specifies the URL of the server-side script that will process the form
 method=
 specifies how the information in the form will be transmitted to the
server. Two possible values:
 get - The browser transmits user-entered form data as part
of the URL specified by the ACTION attribute
f h ifi d b h ib
 post - Browser transmits form input info as part of the HTTP
header

9. <form> Tag
9
 Examples
<form method="get" action="cgi-bin/mailform.pl">
<form id="personal" action="validate.asp" method="post">

10. Form Elements
10
 There are controls within the <form> ... </form>
tags
 <input> tag
 attributes
tt ib t
 name - necessary for the form to be processed
 type - specifies type of control
type="text"
type="password"
type="checkbox"
type="radio"
type="submit"
type="reset"
 Other attributes are possible depending upon the type
O
attribute.

11. 11
Sample <i
S l <input> elements
> l
<input type="text" name="first1">
<input type="text" name="first2" size="10" maxlength="5">
<input type="text" name="first3" value="Karl Marx">
<input type="checkbox" name="chk1"></br/>
Alive <input type="checkbox" name="chk2"></br/>
<input type="checkbox" name="chk3">Alive</br/>
type= checkbox name= chk3 >Alive</br/>
<input type="checkbox" name="chk3" value="something"><br/>
<input type="checkbox" name="chk4" checked="checked"><br/>
<input type="radio" name="sex" value="male"> Male
<input type="radio" name="sex" value="female"> Female
<input type="button" name="click" value="Click Me">
<input type="image" src="images/btn_login.gif" alt="Login">
<input type="submit"></br/>
<input type="submit" value="Ok">
type submit value Ok >

12. Form Elements, continued
12
 Drop-down menus created with
D d d ih
<select> tag
 <select> is a contained for
<option> tags which define list items
<select name="price">
<option>Choose a price</option>
<option>below $10</option>
<option>between $10 and $20</option>
<option>above $20</option>
</select>

13. <select> element
13
 What l i
Wh value is returned from a
df
<select> element?
 Either
 The value attribute for the selected
option
 If no value attribute, then the text of the
option element

14. <select> element
14
<select name="price">
<option value="0">Choose a price</option>
<option value="1">below $10</option> price=1
<option value="2">between $10 and $20</option>
<option value="3">above $20</option>
p p
</select>
<select name="price">
<option>Choose a price</option>
<option>below $10</option> price below%20%2410
price=below%20%2410
<option>between $10 and $20</option>
<option>above $20</option>
</select>

15. Aligning Form Elements
15
 Be sure to align your form
elements !!
l t
 This can be done via
 tables
 CSS

16. Align form elements via tables
16

17. 2. Verify Using Client-Side Scripting
Client Side
17
 Javascript
 is a programming language introduced by Netscape
but available on IE, FireFox and Opera.
 is not the same as Java.

18. Working with Javascript
18
 Typically consists of Javascript f
f functions
that respond to events connected to
HTML t tags
<script language=javascript>
function check_form() {
if (email.value == "") {
if ( il l "") {
alert("please enter an email")
return false
}
}
</script>
<body>
<form>
<input type=submit onclick="check_form()">
...

19. 3. Process Using Server-Side
19
Program
 Server-side
Server side programming is necessary to access
databases, save form data, create customized
pages
 The most popular are
 PHP (PHP Hypertext Processor)
 ASP.NET
ASPNET
 CGI (Common Gateway Interface)
 ASP (Active Server Pages)
 JSP (Java Server Pages)
 Cold Fusion

20. Static Web Content
20
Browser
B Web
Server
Browser requests index.htm from server
Server responds by sending index.htm
to browser

21. Dynamic Web Content
21
Web
Browser Server
1
Browser requests
processForm.asp from server
Server recognizes
request as script or
program
2
3
program
Program runs, getting information
about the request from the server,
interacts with server resources such
as databases, and generates
databases
response (HTML tags) that is sent
back to browser
4
Browser displays HTML it
received from server.

22. form_example.htm
reply.asp
22

23. REPLY.ASP
<html><head><title>Form Example</title></head>
<body>
<h1>Sample Form ASP Script</h1>
<B>The following form items were received:</b><p>
<% for each item in request.form %>
Form
Fo m Item '<% =Item %>' has the value '<% =request.form(item) %>'<b >
Item al e request form(item) %>'<br>
<% next %>
</body>
</html>
<html><head><title>Form Example</title></head>
Generates this code <body>
<h1>Sample Form ASP Script</h1>
<B>The following form items were received:</b><p>
Form Item 'guest' has the value 'Fred'<br>
Form It
F Item ' dd
'address' has the value '123-Anywhere St' b
' h th l '123 A h St'<br>
Form Item 'BUTTON' has the value 'Submit Query'<br>
Form Item 'email' has the value 'fred@abc.net'<br>
Form Item 'city' has the value 'Calgary'<br>
Form Item 'prov' has the value 'AB'<br>
Form Item 'phone' has the value ''<br>
Form Item 'winecolor' has the value 'R'<br>
Form Item 'price' has the value 'between $10 and $20'<br>
</body>
</html>
23

24. Form Accessibility
24
 You can improve the accessibility of your forms by
using
 the , and <legend> elements.
<label> <fieldset>,
 the accesskey and tabindex attributes

25. <label> element
25
 Used to define relationship between the text
describing the form element and the form element
itself.
 Unless styled by CSS, is not displayed by the browser.
 If you click the label, then the form element receives the
focus.
 The form element must have an id specified for this to work
First Name: <input type="text" name="firstname"><br>
<label for="firstname">First Name: </label>
<input type="text" id="firstname" name="firstname">
Clicking on label gives form
element the focus.

26. <fieldset> and <legend>
26
 The <fieldset> groups a set of related form
controls together.
 This fieldset can then be visually styled and given a
label via the <legend> element.
<fieldset>
<legend>Login</legend>
<label for="email">EMail: </label><br>
<input type="text" name="email"><br>
<label for= pass >Password: </label><br>
for="pass">Password:
<input type="password" name="pass"><br>
<input type="button" name="submit" value="Log In">
</fieldset>

27. accesskey and tabindex attributes
27
 accesskey attribute is used to assign an access key
to the form element that works with the program's
modifier key (on Windows browsers this is the Alt key).
f
 Thus <input type="text" name="email" accesskey="m"> could be given
the focus b pressing Alt-M.
h f by i Al M
 The tabindex attribute is used to define the
element's position in the tab order.
'
 E.g. <input type="text" name="email" tabindex="1"> would be the first
element in the tab order.
l h b d
 Links (<a> tag) can also be given these two attributes.

28. 28

29. <form name="form1" method="" action="">
<fieldset>
<legend>Login</legend>
<label>Your email</label>
<input type="text" name="email" /><br />
<label>Your password</label>
<input type="password" name="password" /><br />
i " d" " d" / b /
<input type="checkbox" name="remember" />
Remember me<br />
<label>Server </label>
<input type="radio" name="server" value="one"> One
p yp
<input type="radio" name="server" value="two"> Two<br />
<label>Domain</label>
<select name="domain">
<option>Abc</option>
<option>Def</option>
<option>Ghi</option>
</select><br />
<input type="submit" />
</fieldset>
</form>
/f
29

30. 30

31. 31