A basic example using PHP to create a basic login form.
In this example we will create a simple login process that will include four steps:
- The first page will be an HTML form with a email and password textbox.
- If the password is correct, the second page will save the email address to a session.
- The thirs page will include a welcome message and display the email address from the session.
- The final page will remove all session data and redirect the visitor to the first page.
Create a new HTML file called step-1.html. This file will not require any PHP so it can be given an HTML extension. Add the standard HTML tags to the file and place the following HTML form in the body:
<form method="post" action="step-2.php">
Username:
<input type="text" name="email">
<br>
Password:
<input type="password" name="password">
<br>
<input type="submit" value="Login">
</form>Create a new file called step-2.php.
Notice that the action in step-1.html is set to step-2.php. This page will be loaded when the HTML form in the first has been submitted. When a PHP file receives form data it is available by referenceing a special PHP array called $_POST or $_GET.
Open your new file and add the standard HTML tags. Above the doctype tag add the following PHP whcih will check to see if the provided email and password is correct:
<?php
session_start();
if( $_POST['email'] == 'jane.doe@email.com' and $_POST['password'] == 'password' )
{
$_SESSION['login'] = true;
$_SESSION['email'] = $_POST['email'];
}
?>If the email address and password are correct, this code will save the member's email address and a logged in status of true to a session.
Note
A session allows a server side langauge to temporarily store data about a website visitor. It's similar to a cookie except the data resides on the sever and cookie data resides on the client computer.
To use a session in PHP our code simply needs to initiate a session by executing the session_start() function. After the session has been initialized, session data can be created or referenced by using the $_SESSION array.
In the body add a message for a successful login and a second message for an error:
<?php if( isset( $_SESSION['login'] ) ): ?>
<h2>Success!</h2>
<p>You have been logged in!</p>
<a href="step-3.php">Continue to Step 3</a>
<?php else: ?>
<h2>Error!</h2>
<p>Incorrect email and/or password!</p>
<a href="step-1.html">Try Again</a>
<?php endif; ?>Note
If you are testing this file make sure you upload both files to your server and start by loading step-1.html. The second file will not work properly without receiving the form data from the first file.
Create a new file called step-3.php. Open your new file and add the standard HTML tags. Above the doctype tage add the following code:
<?php
session_start();
?>This file will display the logged in member's email address by referencing the data in the session. Add the standard HTML tags and add this PHP in the body:
<p>You are logged in as <?php echo $_SESSION['email']; ?>.</p>
<a href="step-4.php">Logout</a>Create a new file named step-4.php. This file will simply use the session_destroy() function to remove all session data.
Above the doctype tag add the following PHP code:
<?php
session_start();
session_destroy();
?>Within the body tag add a message informing visitors they have been logged out and a link back to step-1.html:
<p>You have been logged out!</p>
<a href="step-1.html">Start Again</a>Upload all four files to your server and test by loading step-1.html.
For a challenge, adjust the four files above to use cookies instead of sessions. All of the code can remain the same except the code that creates or references session data.
Full tutorial URL:
https://codeadam.ca/learning/php-forms-session-cookies.html
