PHP项目中点击登录按钮跳转空白页，如何关联主Header实现正常跳转？

问题概述 #

我正在开发PHP项目的登录与注册页面，已用HTML完成表单编写，但需要关联PHP主Header文件让其在所有页面生效。目前点击登录按钮后会跳转到空白页面，相关代码如下：

头部代码 #

<div id="top-header">
<img src="/phpmotors/images/site/logo.png" alt="PHP Motors logo" id="logo">
<a href="/phpmotors/accounts/index.php?action=login.php" title="Login or Register with PHP Motors" id="acc">My Account</a>

控制器Index.PHP代码 #

// Get the database connection file
require_once '../library/connections.php';
// Get the PHP Motors model for use as needed
require_once '../model/main-model.php';

//Get the array of classifications from the database using the model.
$classifications = getClassifications();

// Build a navigation bar using the $classifications array
$navList = '<ul>';
$navList .= "<li><a href='/phpmotors/index.php' title='View the PHP Motors home page'>Home</a></li>";
foreach ($classifications as $classification) {
 $navList .= "<li><a href='/phpmotors/index.php?action=".urlencode($classification['classificationName'])."' title='View our $classification[classificationName] product line'>$classification[classificationName]</a></li>";
}
$navList .= '</ul>';

$action = filter_input(INPUT_GET, 'action');
if ($action == NULL) {
  $action = filter_input(INPUT_POST, 'action');
}

//Get the database of login information
$clientEmail = filter_input(INPUT_POST, 'clientEmail');
$clientPassword = filter_input(INPUT_POST, 'clientPassword');

//Get the database of registration information
$clientFirst = filter_input(INPUT_POST, 'clientFirstname');
$clientLast = filter_input(INPUT_POST, 'clientLast');
$clientEmail = filter_input(INPUT_POST, 'clientEmail');
$clientPassword = filter_input(INPUT_POST, 'clientPassword');

switch ($action) {
  case 'login':
    include 'view\login.php';
    break;
  case 'registration':
    include 'view\registration.php';

default:
    include 'view/home.php';
}
?>
</div>

表单HTML代码 #

<h1>Sign in</h1>
<form action="/accounts/" method="POST">
    <label>Email</label>
    <br>
    <input name="clientEmail" id="clientEmail" type="email" <?php if(isset($clientEmail)){echo "value='$clientEmail'";}  ?> required>
    <br>
    <br>
    <label>Password</label>
    <br>
    <input name="clientPassword" id="clientPassword" type="password">
    <br>
    <input type="submit" name="submit" id="regbtn" value="Login">
    <!-- Add the action name - value pair -->
    <input type="hidden" name="action" value="Login">
</form>
<p>
    <a href = "/accounts/index.php/?action=registration">Not a member yet?</a>
</p>

问题修复方案 #

1. 修正表单提交路径 #

表单当前action="/accounts/"无法精准指向控制器，改为直接指向控制器文件：

<form action="/phpmotors/accounts/index.php" method="POST">

2. 统一action参数大小写 #

PHP对字符串大小写敏感，表单隐藏域的action值为Login，但控制器switch判断的是login，修改表单隐藏域：

<input type="hidden" name="action" value="login">

3. 全局引入Header文件 #

创建独立的header.php文件存放头部代码，然后在所有视图文件（login.php、registration.php、home.php）顶部添加引入代码：

<?php include '../includes/header.php'; ?>

同时修正头部的登录链接，去掉多余的.php后缀：

<a href="/phpmotors/accounts/index.php?action=login" title="Login or Register with PHP Motors" id="acc">My Account</a>

4. 修复控制器代码问题 #

• 移除重复的$clientEmail和$clientPassword赋值，避免覆盖；
• 将Windows风格的路径分隔符\改为跨平台的/：

case 'login':
    include 'view/login.php';
    break;
case 'registration':
    include 'view/registration.php';

5. 排查空白页问题 #

若修复后仍显示空白，在控制器开头开启错误提示，定位具体问题：

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

内容的提问来源于stack exchange，提问作者KwameDickson