Learning PHP, MySQL, JavaScript, and CSS, 2nd Edition

login.php

With users now able to sign up to the site, Example 21-7, login.php, provides the code needed to let them log in. Like the signup page, it features a simple HTML form and some basic error checking, as well as using sanitizeString before querying the MySQL database.

The main thing to note here is that, upon successful verification of the username and password, the session variables 'user' and 'pass' are given the username and password values. As long as the current session remains active these variables will be accessible by all the programs in the project, allowing them to automatically provide access to logged-in users.

You may be interested in the use of the die function upon successfully logging in. This is there because it combines an echo and an exit command in one, thus saving a line of code. For styling, this file (like most of the others) applies the class main to indent the content from the lefthand edge.

When you call up this program in your browser, it should look like Figure 21-3. Note how the <input /> type of password has been used here to mask the password with asterisks to prevent it from being viewed by anyone looking over the user’s shoulder.

Example 21-7. login.php

<?php // login.php include_once 'header.php'; echo "<div class='main'><h3>Please enter your details to log in</h3>"; $error = $user = $pass = ""; if (isset($_POST['user'])) { $user = sanitizeString($_POST['user']); $pass = sanitizeString($_POST['pass']); if ($user == "" || $pass == "") { $error ...