重定向后修改页面数据

Question

我正在使用 php 代码制作一个 web 页面，其中 index.php 代码在用户成功登录后更改。用户在登录前从 index.php 开始，被定向到 login.php，然后重定向回 index.881435283519 index.php 在登录前后有完全不同的代码。我想知道对页面进行修改的正确方法是什么，因为我正在尝试 if 语句，但它们似乎不起作用。

索引页

<?php

   require_once "pdo.php";
   session_start();
?>
 <!DOCTYPE html>
 <html>
        <head>
        <title>Index Page</title>
    </head>
     <body>
       <div class="container">
          <h2>Welcome to the Automobiles Database</h2>
          <?php
          if ( isset($_SESSION['error']) ) {
          echo '<p style="color:red">'.$_SESSION['error']."</p>\n";
          unset($_SESSION['error']);
          }
          if ( isset($_SESSION['success']) ) {
          echo '<p style="color:green">'.$_SESSION['success']."</p>\n";
          unset($_SESSION['success']);
          }
          if(!isset($_POST['email']) || !isset($_POST['pass']))//this code should work if the 
                                                                //user is not loged in
          {
          echo '<p><a href="login.php">Please log in</a></p>' ;
          echo '<p>Attempt to <a href="add.php">add data</a> without logging in</p>' ;
          }
          if(isset($_POST['email']) && isset($_POST['pass']))//this code should work if the user      
                                                             //is loged in
          {  
         if(isset($_POST['make']) && isset($_POST['year']) && isset($_POST['model']) &&                                                
         isset($_POST['mileage']))//this code should work if the user entered data
         {

          echo('<table border="1">'."\n");
          $stmt = $pdo->query("SELECT * autos");
          while ( $row = $stmt->fetch(PDO::FETCH_ASSOC) ) {
          echo "<tr><td>";
          echo(htmlentities($row['make']));
          echo("</td><td>");
          echo(htmlentities($row['model']));
          echo("</td><td>");
          echo(htmlentities($row['year']));
          echo("</td><td>");
          echo(htmlentities($row['mileage']));
          echo("</td><td>");
          echo('<a href="edit.php?user_id='.$row['user_id'].'">Edit</a> / ');
          echo('<a href="delete.php?user_id='.$row['user_id'].'">Delete</a>');
          echo("</td></tr>\n");
  }
}
         else if(!isset($_POST['make']) || !isset($_POST['year']) || !isset($_POST['model']) ||     
         !isset($_POST['mileage']))//this code should work if the user didn't enter data
         {
         echo "<p>no rows found</p>";

         }
    echo '<p><a href="add.php">Add New Entery</a></p>';
    echo '<p><a href="logout.php">Logout</a></p>';
}
?>

登录页面

<?php

   require_once "pdo.php";
   session_start();
   if ( isset($_POST['cancel'] ) ) {
        header("Location: login.php?name=".urlcode($_POST['email']));
       return;
    }

$salt = "XyZzy12*_";
$stored_hash = "1a52e17fa899cf40fb04cfc42e6352f1";  // Pw is php 123

$failure = false;  // If we have no POST data

// Check to see if we have some POST data, if we do process it
if ( isset($_POST['email']) && isset($_POST['pass']) ) {
    if ( strlen($_POST['email']) < 1 || strlen($_POST['pass']) < 1 ) {
        $_SESSION['error'] = "User name and password are required";
        header("Location: login.php");
        return;
    }    
    else if (!filter_var($_POST["email"], FILTER_VALIDATE_EMAIL)) {
        $_SESSION['error'] = "Email must have an at-sign (@)";
        header("Location: login.php");
        return;
    } 
     else {
        $check = hash('md5', $salt.$_POST['pass']);
        if ( $check == $stored_hash ) {
            error_log("Login success ".$_POST['email']);
            $_SESSION['name'] = $_POST['email'];
            header("Location: index.php");
            return;
        } else {
            error_log("Login fail ".$_POST['email']." $check");
            $_SESSION['error'] = "Incorrect password";
            header("Location: login.php");
            return;
        }
    }
}
?>
<!DOCTYPE html>
<html>
    <head>
    <title>Login Page</title>
    <link rel="stylesheet" 
        href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" 
        integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" 
        crossorigin="anonymous">

    <link rel="stylesheet" 
       href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap-theme.min.css" 
       integrity="sha384-fLW2N01lMqjakBkx3l/M9EahuwpSfeNvV63J5ezn3uZzapT0u7EYsXMjQV+0En5r" 
       crossorigin="anonymous">

    <link rel="stylesheet" 
       href="https://code.jquery.com/ui/1.12.1/themes/ui-lightness/jquery-ui.css">

   <script
       src="https://code.jquery.com/jquery-3.2.1.js"
       integrity="sha256-DZAnKJ/6XZ9si04Hgrsxu/8s717jcIzLy3oi35EouyE="
       crossorigin="anonymous"></script>

   <script
        src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"
        integrity="sha256-T0Vest3yCU7pafRw9r+settMBX6JkKN06dqBnpQ8d30="
        crossorigin="anonymous"></script>
   </head>
   <body>
      <div class="container">
        <h1>Please Log In</h1>
   <?php
       if ( isset($_SESSION['error']) ) {
       echo('<p style="color: red;">'.htmlentities($_SESSION['error'])."</p>\n");
       unset($_SESSION['error']);
       }  
  ?>
    <form method="POST" action="login.php">
      User Name <input type="text" name="email"><br/>
      Password <input type="text" name="pass"><br/>
      <input type="submit" value="Log In">
      <a href="index.php">Cancel</a></p>
    </form>
    <p>
    For a password hint, view source and find a password hint
    in the HTML comments.
    <!-- Hint: The password is the three character name of the
    programming language used in this class (all lower case)
    followed by 123. -->
    </p>
   </div>
 </body>
</html>

Answer 1

你应该制作 3 页。

在索引中，检查用户是否已登录。 如果登录，则重定向到主页。 如果没有记录，调用 die() 并重定向到登录页面。