使用 php session 根据登录状态显示两个不同的 html 页面

Question

我用 php、mysql 和 html 创建了一个登录系统。 我试图弄清楚如何根据某人是否登录来使用 html 代码显示不同的主页。

我试图在 header 上显示配置文件按钮，如果他们已登录，如果他们未登录，则会在 header 上显示登录/注册。

index.php

<?php session_start(); 
include('server.php');
if (isset($_SESSION['username'])){
?>
<!DOCTYPE html>
<html lang = "en">

<!-- 
    Capstone Project "Zoeker"
    Michael Burnett, Annie Lalor, Sophia Michael, Hannah Smith
    5/6/2021
-->


<head>
    <title>Home Page</title>
    <meta charset="utf-8">
    <meta http-equiv="x-ua-compatible" content="ie=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- Stylesheets -->
    <link rel="stylesheet" href="CSS/Normalize.css?v=<?php echo time(); ?>">
    <link rel="stylesheet" href="CSS/Styles.css?v=<?php echo time(); ?>">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
</head>




<body>

<script>
    function myFunction() {
  var x = document.getElementById("myTopnav");
  if (x.className === "topnav") {
    x.className += " responsive";
  } else {
    x.className = "topnav";
  }
}
    </script>
    <!-- Menu Bar -->
    <div class="topnav" id="myTopnav">
        <a href="index.php"><img src="Images/Logo.png" alt="Zoeker"></a>
        <a href="about.php" class="active">About</a>
        <a href="contact.php">Contact</a>
        <a href="stores.php">Stores Near You</a>
        <a href="login.php"style="float:right">Profile</a>
        <a href="javascript:void(0);" class="icon" onclick="myFunction()">
        <i class="fa fa-bars"></i>
    </a>
    </div>
     
    <!-- Strip container for opening home page -->
    <div class = "strip1">
        
    </div>
    
    <!-- FOOTER Containers-->
    
    <div class="footer">
        <div class="footer-box">
            <ul>
                <li><a href="index.php"><img src="Images/Logo.png" alt="Zoeker"></a></li>
            </ul>
        </div>
        <div class="footer-box">
            <h2>Navigation</h2>
            <ul>
                <li><a href="stores.php">Stores</a></li>
                <li><a href="about.php">About Us</a></li>
                <li><a href="contact.php">Contact</a></li>
            </ul>
        </div>
        <div class="footer-box">
            <h2>Service Areas</h2>
            <ul>
                <li>Bloomington</li>
            </ul>
        </div>
        <div class="footer-box">
            <h2>Contact Us</h2>
            <ul>
                <li>812-123-4567</li>
                <li>Support@Zoeker.com</li>
            </ul>
        </div>
    </div>
    
</body>
</html>

<?php
}else{
    // not logged in
}
?>
<!DOCTYPE html>
<html lang = "en">

<!-- 
    Capstone Project "Zoeker"
    Michael Burnett, Annie Lalor, Sophia Michael, Hannah Smith
    5/6/2021
-->


<head>
    <title>Home Page</title>
    <meta charset="utf-8">
    <meta http-equiv="x-ua-compatible" content="ie=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- Stylesheets -->
    <link rel="stylesheet" href="CSS/Normalize.css?v=<?php echo time(); ?>">
    <link rel="stylesheet" href="CSS/Styles.css?v=<?php echo time(); ?>">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
</head>




<body>

<script>
    function myFunction() {
  var x = document.getElementById("myTopnav");
  if (x.className === "topnav") {
    x.className += " responsive";
  } else {
    x.className = "topnav";
  }
}
    </script>
    <!-- Menu Bar -->
    <div class="topnav" id="myTopnav">
        <a href="index.php"><img src="Images/Logo.png" alt="Zoeker"></a>
        <a href="about.php" class="active">About</a>
        <a href="contact.php">Contact</a>
        <a href="stores.php">Stores Near You</a>
        <a href="login.php"style="float:right">Login/Signup</a>
        <a href="javascript:void(0);" class="icon" onclick="myFunction()">
        <i class="fa fa-bars"></i>
    </a>
    </div>
     
    <!-- Strip container for opening home page -->
    <div class = "strip1">
        
    </div>
    
    <!-- FOOTER Containers-->
    
    <div class="footer">
        <div class="footer-box">
            <ul>
                <li><a href="index.php"><img src="Images/Logo.png" alt="Zoeker"></a></li>
            </ul>
        </div>
        <div class="footer-box">
            <h2>Navigation</h2>
            <ul>
                <li><a href="stores.php">Stores</a></li>
                <li><a href="about.php">About Us</a></li>
                <li><a href="contact.php">Contact</a></li>
            </ul>
        </div>
        <div class="footer-box">
            <h2>Service Areas</h2>
            <ul>
                <li>Bloomington</li>
            </ul>
        </div>
        <div class="footer-box">
            <h2>Contact Us</h2>
            <ul>
                <li>812-123-4567</li>
                <li>Support@Zoeker.com</li>
            </ul>
        </div>
    </div>
    
</body>
</html>

server.php

<?php
    session_start();
    $username = "";
    $email = "";
    $errors = array();
    //Connect to the database
    $conn = mysqli_connect("db.luddy.indiana.edu", "i494f20_team36", "my+sql=i494f20_team36", "i494f20_team36");

// Check connection
if (mysqli_connect_errno()) {
    echo "Failed to connect to MySQL: ";
}

    //if the register button is clicked
    if (isset($_POST['register'])){
        $username = $_POST['username'];
        $email = $_POST['email'];
        $password = $_POST['password'];
        
        //Check database for username and email already in use
        $sql_u = "SELECT * FROM users WHERE username='$username'";
        $sql_e = "SELECT * FROM users WHERE email='$email'";
        $res_u = mysqli_query($conn, $sql_u);
        $res_e = mysqli_query($conn, $sql_e);
        //ensure form fields are filled in 
        if(empty($username)){
            array_push($errors, "Username is required");
        }
        if(empty($email)){
            array_push($errors, "Email is required");
        }
        if(empty($password)){
            array_push($errors, "Password is required");
        }
        if(mysqli_num_rows($res_u) > 0) {
            array_push($errors, "Username is already taken");
        }
        if(mysqli_num_rows($res_e) > 0) {
            array_push($errors, "Email is already taken");
        }
        //if no errors, insert new user into database
        if (count($errors) == 0){
            $sql = "INSERT INTO users(username, email, password) 
                    VALUES ('$username', '$email', '$password')";
            mysqli_query($conn, $sql);
        
    
      
            $_SESSION['username'] = $username;
            $_SESSION['success'] = "You are now logged in";
            header('location: index.php'); //redirect to home page
        }
        else{
            echo "not quite, but you'll get it";
        }
    }

    // log user in from login page
    if (isset($_POST['login'])){
        $username = $_POST['username'];
        $password = $_POST['password'];
        
        if(empty($username)){
            array_push($errors, "Username is required");
        }
        if (empty($password)){
            array_push($errors, "Password is required");
        }
        if (count($errors) == 0){
            $sql = "SELECT * FROM users WHERE username='$username' AND password='$password'";
            $result = mysqli_query($conn, $sql);
            if (mysqli_num_rows($result) == 1){
                // log user in
                $_SESSION['username'] = $username;
                $_SESSION['success'] = "You are now logged in";
                header('location: index.php'); //redirect to home page
            }else{
                array_push($errors, "Wrong username/password combination");
            }
        } 
    }

?>

Answer 1

else为空，始终显示未登录用户的 html 版本。 通过将结束的 else-bracket 移动到文件的末尾，您可以获得 2 个版本，具体取决于是否登录的用户。

    <?php
    }else{
        // not logged in
    // THE CLOSING BRACKET IS NOW AT THE BOTTOM
    ?>
    <!DOCTYPE html>
    <html lang = "en">
    
    <!-- LINES DELETED FOR BREVITY ->
        
    </body>
    </html>
    <?php } // MOVED CLOSING BRACKET TO THE END