HTML Forms(HTML5it)
HTML Forms
HTML Forms are required when you want to collect
some data from the site visitor. For example during user registration you would
like to collect information such as name, email address, credit card, etc.
A form will take input from the site visitor and
then will post it to a back-end application such as CGI, ASP Script or PHP
script etc. The back-end application will perform required processing on the
passed data based on defined business logic inside the application.
There are various form elements available like text
fields, textarea fields, drop-down menus, radio buttons, checkboxes, etc.
The HTML <form> tag is used
to create an HTML form and it has following syntax:
<form action="Script URL" method="GET|POST">
form elements like input,
textarea etc.
</form>
Form Attributes
Apart from common attributes, following is a list
of the most frequently used form attributes:
Attribute
|
Description
|
action
|
Backend script ready to process your passed data.
|
method
|
Method to be used to upload data. The most
frequently used are GET and POST methods.
|
target
|
Specify the target window or frame where the
result of the script will be displayed. It takes values like _blank, _self,
_parent etc.
|
enctype
|
You can use the enctype attribute to specify how
the browser encodes the data before it sends it to the server. Possible
values are:
·
application/x-www-form-urlencoded - This is the standard method most forms
use in simple scenarios.
·
mutlipart/form-data - This is used when you want to upload
binary data in the form of files like image, word file etc.
|
Note: You
can refer to Perl & CGI for a detail on how
form data upload works.
HTML Form Controls
There are different types of form controls that you
can use to collect data using HTML form:
·
Text Input Controls
·
Checkboxes Controls
·
Radio Box Controls
·
Select Box Controls
·
File Select boxes
·
Hidden Controls
·
Clickable Buttons
·
Submit and Reset Button
Text Input Controls
There are three types of text input used on forms:
·
Single-line text
input controls - This control is used for items
that require only one line of user input, such as search boxes or names. They
are created using HTML <input> tag.
·
Password input
controls - This is also a single-line text
input but it masks the character as soon as a user enters it. They are also
created using HTMl <input> tag.
·
Multi-line text input
controls - This is used when the user is
required to give details that may be longer than a single sentence. Multi-line
input controls are created using HTML <textarea> tag.
Single-line text input controls
This control is used for items that require only
one line of user input, such as search boxes or names. They are created using
HTML <input> tag.
Example
Here is a basic example of a single-line text input
used to take first name and last name:
<!DOCTYPE
html>
<html>
<head>
<title>Text Input Control</title>
</head>
<body>
<form >
First name: <input type="text" name="first_name" />
<br>
Last name: <input type="text" name="last_name" />
</form>
</body>
</html>
This will produce following result:
First name:
Last name:
Last name:
Attributes
Following is the list of attributes for
<input> tag for creating text field.
Attribute
|
Description
|
type
|
Indicates the type of input control and for text
input control it will be set to text.
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
value
|
This can be used to provide an initial value
inside the control.
|
size
|
Allows to specify the width of the text-input
control in terms of characters.
|
maxlength
|
Allows to specify the maximum number of
characters a user can enter into the text box.
|
Password input controls
This is also a single-line text input but it masks
the character as soon as a user enters it. They are also created using HTML
<input> tag but type attribute is set to password.
Example
Here is a basic example of a single-line password
input used to take user password:
<!DOCTYPE
html>
<html>
<head>
<title>Password Input Control</title>
</head>
<body>
<form >
User ID : <input type="text" name="user_id" />
<br>
Password: <input type="password" name="password" />
</form>
</body>
</html>
This will produce following result:
User ID :
Password:
Password:
Attributes
Following is the list of attributes for
<input> tag for creating password field.
Attribute
|
Description
|
type
|
Indicates the type of input control and for
password input control it will be set to password.
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
value
|
This can be used to provide an initial value
inside the control.
|
size
|
Allows to specify the width of the text-input
control in terms of characters.
|
maxlength
|
Allows to specify the maximum number of
characters a user can enter into the text box.
|
Multiple-Line Text Input Controls
This is used when the user is required to give
details that may be longer than a single sentence. Multi-line input controls
are created using HTML <textarea> tag.
Example
Here is a basic example of a multi-line text input
used to take item description:
<!DOCTYPE
html>
<html>
<head>
<title>Multiple-Line Input Control</title>
</head>
<body>
<form>
Description : <br />
<textarea rows="5" cols="50" name="description">
Enter description
here...
</textarea>
</form>
</body>
</html>
This will produce following result:
Description :
Attributes
Following is the list of attributes for
<textarea> tag.
Attribute
|
Description
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
rows
|
Indicates the number of rows of text area box.
|
cols
|
Indicates the number of columns of text area box
|
Checkbox Control
Checkboxes are used when more than one option is
required to be selected. They are also created using HTML <input> tag but
type attribute is set to checkbox.
Example
Here is an example HTML code for a form with two
checkboxes:
<!DOCTYPE
html>
<html>
<head>
<title>Checkbox Control</title>
</head>
<body>
<form>
<input type="checkbox" name="maths" value="on"> Maths
<input type="checkbox" name="physics" value="on"> Physics
</form>
</body>
</html>
This will produce following result:
Maths Physics
Attributes
Following is the list of attributes for
<checkbox> tag.
Attribute
|
Description
|
type
|
Indicates the type of input control and for
checkbox input control it will be set to checkbox.
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
value
|
The value that will be used if the checkbox is
selected.
|
checked
|
Set to checked if you want to
select it by default.
|
Radio Button Control
Radio buttons are used when out of many options,
just one option is required to be selected. They are also created using HTML
<input> tag but type attribute is set to radio.
Example
Here is example HTML code for a form with two radio
buttons:
<!DOCTYPE
html>
<html>
<head>
<title>Radio Box Control</title>
</head>
<body>
<form>
<input type="radio" name="subject" value="maths"> Maths
<input type="radio" name="subject" value="physics"> Physics
</form>
</body>
</html>
This will produce following result:
Maths Physics
Attributes
Following is the list of attributes for radio
button.
Attribute
|
Description
|
type
|
Indicates the type of input control and for
checkbox input control it will be set to radio.
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
value
|
The value that will be used if the radio box is
selected.
|
checked
|
Set to checked if you want to
select it by default.
|
Select Box Control
A select box, also called drop down box which
provides option to list down various options in the form of drop down list,
from where a user can select one or more options.
Example
Here is example HTML code for a form with one drop
down box
<!DOCTYPE
html>
<html>
<head>
<title>Select Box Control</title>
</head>
<body>
<form>
<select name="dropdown">
<option value="Maths" selected>Maths</option>
<option value="Physics">Physics</option>
</select>
</form>
</body>
</html>
This will produce following result:
Attributes
Following is the list of important attributes of
<select> tag:
Attribute
|
Description
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
size
|
This can be used to present a scrolling list box.
|
multiple
|
If set to "multiple" then allows a user
to select multiple items from the menu.
|
Following is the list of important attributes of
<option> tag:
Attribute
|
Description
|
value
|
The value that will be used if an option in the
select box box is selected.
|
selected
|
Specifies that this option should be the
initially selected value when the page loads.
|
label
|
An alternative way of labeling options
|
File Upload Box
If you want to allow a user to upload a file to
your web site, you will need to use a file upload box, also known as a file
select box. This is also created using the <input> element but type
attribute is set to file.
Example
Here is example HTML code for a form with one file
upload box:
<!DOCTYPE
html>
<html>
<head>
<title>File Upload Box</title>
</head>
<body>
<form>
<input type="file" name="fileupload" accept="image/*" />
</form>
</body>
</html>
This will produce following result:
Attributes
Following is the list of important attributes of
file upload box:
Attribute
|
Description
|
name
|
Used to give a name to the control which is sent
to the server to be recognized and get the value.
|
accept
|
Specifies the types of files that the server
accepts.
|
Button Controls
There are various ways in HTML to create clickable
buttons. You can also create a clickable button using <input> tag by
setting its type attribute to button. The type attribute can take
the following values:
Type
|
Description
|
submit
|
This creates a button that automatically submits
a form.
|
reset
|
This creates a button that automatically resets
form controls to their initial values.
|
button
|
This creates a button that is used to trigger a
client-side script when the user clicks that button.
|
image
|
This creates a clickable button but we can use an
image as background of the button.
|
Example
Here is example HTML code for a form with three
types of buttons:
<!DOCTYPE
html>
<html>
<head>
<title>File Upload Box</title>
</head>
<body>
<form>
<input type="submit" name="submit" value="Submit" />
<input type="reset" name="reset"
value="Reset" />
<input type="button" name="ok" value="OK"
/>
<input type="image" name="imagebutton" src="/html/images/logo.png" />
</form>
</body>
</html>
This will produce following result:
Hidden Form Controls
Hidden form controls are used to hide data inside
the page which later on can be pushed to the server. This control hides inside
the code and does not appear on the actual page. For example, following hidden
form is being used to keep current page number. When a user will click next
page then the value of hidden control will be sent to the web server and there
it will decide which page has be displayed next based on the passed current
page.
Example
Here is example HTML code to show the usage of
hidden control:
<!DOCTYPE
html>
<html>
<head>
<title>File Upload Box</title>
</head>
<body>
<form>
<p>This is page 10</p>
<input type="hidden" name="pagename" value="10" />
<input type="submit" name="submit" value="Submit" />
<input type="reset" name="reset"
value="Reset" />
</form>
</body>
</html>
This will produce following result:
This is page 10
Comments
Post a Comment