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Introduction to Computing

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Introduction to Computing ­ CS101
VU
LESSON 12
INTERACTIVE FORMS
(Web Development Lesson 4)
Focus of the last Lesson was on HTML Lists & Tables
We learnt how to extend our Web pages by adding a few more tags
Specifically, we discussed various types of lists that can be added to a Web page ­ un-ordered, ordered
and definition lists
And also, about tables: about various tags used in a table and their associated attributes
Today's Lecture
We will try to understand the utility of forms on Web pages
We will find out about the various components that are used in a form
We will become able to build a simple, interactive form
Interactive Forms (1)
Without forms, a Web site is "read-only" ­ it just provides information to the user
Forms enable the user to provide information to the Web site. For example, the user can:
Perform searches on Web site
Give comments
Ask for info that is not available on the Website
Place order for goods and services
Interactive Forms (2)
Can be simple or very complex
Can fill a whole page or just a single line
Can contain a single element or many
Are always placed between the <BODY> and </BODY> tags of a Web page
Interactive Forms (3)
Are GUI-based
May contain:
Text fields
Check boxes
Buttons
Scrollable lists
A Simple
Example
of
Interactive
Forms
Code for that Example
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Introduction to Computing ­ CS101
VU
<HTML>
<HEAD>
<TITLE>Send Email to me</TITLE>
</HEAD>
<BODY>
<H1>Send Email to me</H1>
Code for the instructions
Code for the form
</BODY>
</HTML>
A Simple
Example
of
Interactive
Forms
Code for the Instructions
<P>To send an eMail message to me:</P>
<OL>
<LI>Type your eMail address in the "From" field</LI>
<LI>Type a short message in the "Message" field</LI>
<LI>Press the "Send eMail to me" button</LI>
</OL>
A Simple
Example
of
Interactive
Forms
Code for the Form
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Introduction to Computing ­ CS101
VU
<FORM name="sendEmail" method="post"
action="sendMailScriptURL">
Elements of the form
</FORM>
<FORM name="sendEmail" method="post"
action="sendMailScriptURL">
Elements of the form
</FORM>
name: Name given to the form
method: Forms can be submitted through two
alternate methods ­ GET & POST
action: Specifies the URL that is accessed
when the form is being submitted
12.1 Server-Side Scripts
Are programs that reside on Web servers
Receive info that a user enters in a form
Process that info and take appropriate action
Examples:
CGI scripts on Unix servers
ASP scripts on Windows servers
A Simple
Example
of
Interactive
Forms
Elements of the Form (1)
<P>From: <INPUT type="text" name="sender" size="50"></P>
<P>Message: <INPUT type="text" name="message" size="50"></P>
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Introduction to Computing ­ CS101
VU
A Simple
Example
of
Interactive
Forms
Elements of the Form (2)
<P><INPUT type="hidden" name="receiver"
value="altaf@vu.edu.pk"></P>
<P><INPUT type="hidden" name="subject"
value="eMail from the form"></P>
<P><INPUT type="submit" name="sendEmail" value="Send eMail to me"></P>
A Simple
Example
of
Interactive
Forms
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Introduction to Computing ­ CS101
VU
<TEXTAREA
name="message"
cols="38"
rows="6"
>
</TEXTAREA>
<FORM name="sendEmail" method="post" action="sendMailScriptURL">
<table><tr>
<td>From: </td>
<td><INPUT type="text" name="sender" size="50"></td>
</tr><tr>
<td>To: </td>
<td><INPUT type="text" name="receiver" size="50"></td>
</tr><tr>
<td>Subject: </td>
<td><INPUT type="text" name="subject" size="50"></td>
</tr><tr>
<td valign="top">Message: </td>
<td><TEXTAREA name="message" cols="38"rows="6">
</TEXTAREA></td>
</tr><tr>
<td colspan="2" align="right">
<INPUT type="submit" name="sendEmail" value="Send eMail">
</td>
</tr></table>
</FORM>
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Introduction to Computing ­ CS101
VU
<INPUT
type="text"
name="sender"
size="50"
value="your eMail address goes here"
Review of the Tags Used in Forms
<FORM>
name="nameOfTheForm"
method="get" or "post"
action="URL"
Elements of the form
</FORM>
Single-Line Text Input Field
<INPUT
type="text"
name="fieldName"
size="widthInCharacters"
maxlength="limitInCharacters"
value="initialDefaultValue"
>
Hidden Input
<INPUT
type="hidden"
name="fieldName"
value="value"
>
Submit Button Input
<INPUT
type="submit"
name="buttonName"
value="displayedText"
>
Multi-Line Text Input Area
<TEXTAREA
name="areaName"
cols="widthInCharacters"
rows="numberOfLines"
> initial default value
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Introduction to Computing ­ CS101
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</TEXTAREA>
This was a review of the new tags (and associated attributes) that we have used in today's examples.
There are many more tags that can be used in a form.
Let us take a look at a few
<form name="login" method="post" action="loginScript">
<table><tr>
<td>User Name: </td>
<td>
<input type="text" name="userName" size="10">
</td>
</tr><tr>
<td>Password: </td>
<td>
<input type="password" name="password" size="10">
</td>
</tr><tr>
<td colspan="2" align="right">
<input type="submit" name="login" value="Log me in">
</td>
</tr></table>
</form>
Password Input Field
<INPUT
type="password"
name="fieldName"
size="widthInCharacters"
maxlength="limitInCharacters"
value="initialDefaultValue"
>
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Introduction to Computing ­ CS101
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<form name="login" method="post" action="loginScript">
<table><tr>
<td>User Name: </td>
<td>
<input type="text" name="userName" size="10">
</td>
</tr><tr>
<td>Password: </td>
<td>
<input type="password" name="password" size="10">
</td>
</tr><tr>
<td colspan="2">
<input type="checkbox" name="remember" value="remember">
Remember my user name and password<br>
</td>
</tr><tr>
<td colspan="2">
<input type="submit" name="login" value="Log me in">
</td>
</tr></table>
</form>
12.2 Checkbox Input Element
<INPUT
type="checkbox"
name="checkboxName"
checked
value="checkedValue"
>
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Introduction to Computing ­ CS101
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<form name="login" method="post" action="loginScript">
<table><tr>
<td>User Name: </td>
<td>
<input type="text" name="userName" size="10">
</td>
</tr><tr>
<td>Password: </td>
<td>
<input type="password" name="password" size="10">
</td>
</tr><tr>
<td valign="top">Logging in from:</td>
<td>
<input type="radio" name="from" value="home"> Home<br>
<input type="radio" name="from" value="office"> Home<br>
<input type="radio" name="from" value="university" checked> University
</td>
</tr><tr>
<td colspan="2" align="right">
<input type="submit" name="login" value="Log me in">
</td>
</tr></table>
</form>
12.3 Radio Button Input Element
<INPUT
type="radio"
name="radioButtonName"
checked
value="selectedValue"
>
What is the difference between checkboxes and radio buttons?
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Introduction to Computing ­ CS101
VU
<form name="login" method="post" action="loginScript">
<table><tr>
<td>User Name: </td>
<td><input type="text" name="userName" size="10"></td>
</tr><tr>
<td>Password: </td>
<td>
<input type="password" name="password" size="10">
</td>
</tr><tr>
<td valign="top">Logging in from:</td>
<td>
<select size="2" name="from">
<option value="home"> Home
<option value="office"> Office
<option value="university" selected> University
</select>
</td>
</tr><tr>
<td colspan="2">
<input type="submit" name="login" value="Log me in">
</td>
</tr></table>
</form>
12.4 Select from a (Drop Down) List
<SELECT
name="listName"
size="numberOfDisplayedChoices"
multiple
>
<OPTION value="value1"> text1
<OPTION value="value2" selected> text2
<OPTION value="value3"> text2
...
...
</SELECT>
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12.5 File Upload Input Element
<INPUT
type="file"
name="buttonName"
value="nameOfSelectedFile"
enctype="fileEncodingType"
>
<form
name="uploadForm"
method="post"
action="uploadScript"
<input
type="file"
name="uploadFile"
enctype="multipart/form-data"
>
<input
type="submit"
name="submit"
value="Upload"
>
</form>
Reset Button Input Element
(Resets the contents of a form to default values)
<INPUT
type="reset"
value="dispalyedText"
>
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Introduction to Computing ­ CS101
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Today's Lesson was the ...
We looked at the utility of forms on Web pages
We found out about the various components that are used in a form
We became able to build a simple, interactive form
73
Table of Contents:
  1. INTRODUCTION
  2. EVOLUTION OF COMPUTING
  3. World Wide Web, Web’s structure, genesis, its evolution
  4. Types of Computers, Components, Parts of Computers
  5. List of Parts of Computers
  6. Develop your Personal Web Page: HTML
  7. Microprocessor, Bus interface unit, Data & instruction cache memory, ALU
  8. Number systems, binary numbers, NOT, AND, OR and XOR logic operations
  9. structure of HTML tags, types of lists in web development
  10. COMPUTER SOFTWARE: Operating Systems, Device Drivers, Trialware
  11. Operating System: functions, components, types of operating systems
  12. Forms on Web pages, Components of Forms, building interactive Forms
  13. APPLICATION SOFTWARE: Scientific, engineering, graphics, Business, Productivity, Entertainment, Educational Software
  14. WORD PROCESSING: Common functions of word processors, desktop publishing
  15. Interactivity to Forms, JavaScript, server-side scripts
  16. ALGORITHMS
  17. ALGORITHMS: Pseudo code, Flowcharts
  18. JavaScript and client-side scripting, objects in JavaScript
  19. Low, High-Level, interpreted, compiled, structured & object-oriented programming languages
  20. Software Design and Development Methodologies
  21. DATA TYPES & OPERATORS
  22. SPREADSHEETS
  23. FLOW CONTROL & LOOPS
  24. DESIGN HEURISTICS. Rule of thumb learned through trial & error
  25. WEB DESIGN FOR USABILITY
  26. ARRAYS
  27. COMPUTER NETWORKS: types of networks, networking topologies and protocols
  28. THE INTERNET
  29. Variables: Local and Global Variables
  30. Internet Services: FTP, Telnet, Web, eMail, Instant messaging, VoIP
  31. DEVELOPING PRESENTATIONS: Effective Multimedia Presentations
  32. Event Handlers
  33. GRAPHICS & ANIMATION
  34. INTELLIGENT SYSTEMS: techniques for designing Artificial Intelligent Systems
  35. Mathematical Functions in JavaScript
  36. DATA MANAGEMENT
  37. DATABASE SOFTWARE: Data Security, Data Integrity, Integrity, Accessibility, DBMS
  38. String Manipulations:
  39. CYBER CRIME
  40. Social Implications of Computing
  41. IMAGES & ANIMATION
  42. THE COMPUTING PROFESSION
  43. THE FUTURE OF COMPUTING
  44. PROGRAMMING METHODOLOGY
  45. REVIEW & WRAP-UP of Introduction to Computing