Hi friends,
In this post am going to explain how we process the data posted from HTML form in PHP page.
If you not aware of HTML forms u can go through my previous post
The values posted from HTML form to php page can be retrieved in 3 ways:
1. Using $_GET - This is used when the values are posted using method 'get' in HTML form tag.
ex: if you have a HTML element with name='email'.
<form method='get' action='targetpage.php'>
<input type='text' name='email'>
</form>
In targetpage.php the value of 'email' field can be retrieved as $_GET['email'].
2. Using $_POST - This is used when the values are posted using method 'post' in HTML form tag.
ex: if you have a HTML element with name='email'.
<form method='post' action='targetpage.php'>
<input type='text' name='email'>
</form>
In targetpage.php the value of 'email' field can be retrieved as $_POST['email'].
3. Using $_REQUEST - This is used when the values are posted using method 'post' or 'get' in HTML form tag.
In targetpage.php the value of 'email' field can be retrieved as $_REQUEST['email'].
Note: $_REQUEST variable can be used in both cases(for get and post also). So It is a better practice to use $_REQUEST for form data processing.
Up to know we learned how to get values from HTML form to php page. Now we'll move a little bit forward i.e using extract() function.
as per our knowledge we can get form values like $_GET['email'], $_POST['email'], and $_REQUEST['email'].
using extract() function makes it easier to use values as php variables.
you can refer description of extract() function
for ex:
<?php
echo $_REQUEST['email']; //prints the email value
?>
<?php
extract($_REQUEST);
echo $email; // prints the email value
?>
the above two pieces of code does same thing i.e prints email value.
But using extract method makes coding easier, when there is a need of using same variable in multiple places.
So, it is better practice to use extract() method to fetch values from $_REQUEST or $_POST or $_GET.
Here is the code for posting values from HTML form and processing them in php page
Form.html:
<html>
<head>
<script language="javascript">
function validate(){
var email=document.getElementById('email').value;
var pass= document.getElementById('pwd').value;
var atpos=email.indexOf("@"); // getting the position of '@' symbol in email
var dotpos=email.lastIndexOf("."); // getting the position of last '.' symbol in email
if(email=="") // if email value is empty
{
alert("please enter email id"); // show an alert message
document.getElementById('email').focus(); // place the cursor in email field
return false; // stop the execution and return false.
}
//checking @ and . positions
else if (atpos<1 || dotpos<atpos+2 || dotpos+2>=email.length)
{
alert("Not a valid e-mail address");
document.getElementById('email').focus();
return false;
}
else if(pass=="") //if password is empty
{
alert("please enter password");
document.getElementById('pwd').focus();
return false;
}
else if(pass.length<6) //if password length is less than 6 chars
{
alert("please enter password");
document.getElementById('pwd').focus();
return false;
}
return true; // if all conditions are satisfied then return true.
}
</script>
</head>
<body>
<form action="targetpage.php" method="post" onsubmit="return validate()">
<table width="100%" align="center">
<tr><th>Email</th><td align="center"><input type="text" name="email" id="email" /></td></tr>
<tr><th>Password</th><td align="center"><input type="password" name="pwd" id="pwd" /></td></tr>
<tr><td colspan="2" align="center"><input type="submit" value="login" /></td></tr>
</table>
</form>
</body>
</html>
---------------------------------------------------------------------------------------
targetpage.php:
<?php
extract($_REQUEST);
echo "Email is: ".$email;
echo "Password is: ".$pwd;
?>
----------------------------------------------------------------------------------------
In my next post I'll explain you how to store values in database and how to retrieve values from database.
Up to then Take Care bye....
Urs Venky..... :)
