在提交之前使用单独的 html 和 php 文件进行 PHP 表单验证 - PHP form validation before submit using separate html and php files

我正在做一个作业，其中我需要使用单独的 html 和 php 文件，但我无法理解如何验证我的表单输入，因为我发现的所有示例在一个文件中都有 html 和 php。

我一直在遵循w3schools上的例子：http：//www.w3schools.com/php/php_form_validation.asp

我w3_example.html：

    <!DOCTYPE HTML> 
<html>
<head>
<style>
.error {color: #FF0000;}
</style>
</head>
<body> 
<?php
// define variables and set to empty values
function test_input($data) {
   $data = trim($data);
   $data = stripslashes($data);
   $data = htmlspecialchars($data);
   return $data;
}
?>
<h2>PHP Form Validation Example</h2>
<p><span class="error">* required field.</span></p>
<form method="post" action="w3_example.php"> 
   Name: <input type="text" name="name">
   <span class="error">* <?php echo $nameErr;?></span>
   <br><br>
   E-mail: <input type="text" name="email">
   <span class="error">* <?php echo $emailErr;?></span>
   <br><br>
   Website: <input type="text" name="website">
   <span class="error"><?php echo $websiteErr;?></span>
   <br><br>
   Comment: <textarea name="comment" rows="5" cols="40"></textarea>
   <br><br>
   Gender:
   <input type="radio" name="gender" value="female">Female
   <input type="radio" name="gender" value="male">Male
   <span class="error">* <?php echo $genderErr;?></span>
   <br><br>
   <input type="submit" name="submit" value="Submit"> 
</form>
</body>
</html>

我w3_example.php：

<!DOCTYPE HTML> 
<html>
<head>
</head>
<body> 
<?php
// define variables and set to empty values
$nameErr = $emailErr = $genderErr = $websiteErr = "";
$name = $email = $gender = $comment = $website = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
   if (empty($_POST["name"])) {
     $nameErr = "Name is required";
   } else {
     $name = test_input($_POST["name"]);
   }
   if (empty($_POST["email"])) {
     $emailErr = "Email is required";
   } else {
     $email = test_input($_POST["email"]);
   }
   if (empty($_POST["website"])) {
     $website = "";
   } else {
     $website = test_input($_POST["website"]);
   }
   if (empty($_POST["comment"])) {
     $comment = "";
   } else {
     $comment = test_input($_POST["comment"]);
   }
   if (empty($_POST["gender"])) {
     $genderErr = "Gender is required";
   } else {
     $gender = test_input($_POST["gender"]);
   }
}


echo "<h2>Your Input:</h2>";
echo $name;
echo "<br>";
echo $email;
echo "<br>";
echo $website;
echo "<br>";
echo $comment;
echo "<br>";
echo $gender;
?>
</body>
</html>

我现在在此行收到"调用未定义的函数 test_input（）"错误 $name = test_input（$_POST["name"]）; 在w3_example.php

只是一个提示！因为你学习和我想象的那样，总是关心你从哪里学习。W3学校的质量不好法典。使用示例中的 http://php.net/manual/en/tutorial.forms.php 这是官方的PHP文档。他们的示例代码、注释等远远优于W3学校。

我再次检查了您的示例代码：

创建 2 个文件：

index.html/index.php（在此示例中，它不关心它是.html格式还是.php格式。
处理程序.php

你第一个文件：索引.html/索引.php

<!DOCTYPE HTML>
<html>
<head>
</head>
<body>
<h2>PHP Form Validation Example</h2>
<form method="post" action="handler.php">
   Name: <input type="text" name="name">
   <br><br>
   E-mail: <input type="text" name="email">
   <br><br>
   Website: <input type="text" name="website">
   <br><br>
   Comment: <textarea name="comment" rows="5" cols="40"></textarea>
   <br><br>
   Gender:
   <input type="radio" name="gender" value="female">Female
   <input type="radio" name="gender" value="male">Male
   <br><br>
   <input type="submit" name="submit" value="Submit">
</form>
</body>
</html>

您的第二个文件：处理程序.php

<?php
// define variables and set to empty values
$name = $email = $gender = $comment = $website = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
   $name = test_input($_POST["name"]);
   $email = test_input($_POST["email"]);
   $website = test_input($_POST["website"]);
   $comment = test_input($_POST["comment"]);
   $gender = test_input($_POST["gender"]);
}
function test_input($data) {
   $data = trim($data);
   $data = stripslashes($data);
   $data = htmlspecialchars($data);
   return $data;
}
echo "<h2>Your Input:</h2>";
echo $name;
echo "<br>";
echo $email;
echo "<br>";
echo $website;
echo "<br>";
echo $comment;
echo "<br>";
echo $gender;
?>

此选项将在表单中以不同的页面URL显示您的输入。

那会起作用！

顺便说一句，我真的不喜欢那个糟糕的示例代码。请使用：

<?php
// define variables and set to empty values
$name = $email = $gender = $comment = $website = "";
if (isset($_POST["submit"])){
       $name = test_input($_POST["name"]);
       $email = test_input($_POST["email"]);
       $website = test_input($_POST["website"]);
       $comment = test_input($_POST["comment"]);
       $gender = test_input($_POST["gender"]);
        echo "<h2>Your Input:</h2>";
        echo $name;
        echo "<br>";
        echo $email;
        echo "<br>";
        echo $website;
        echo "<br>";
        echo $comment;
        echo "<br>";
        echo $gender;
    }
function test_input($data) {
   $data = trim($data);
   $data = stripslashes($data);
   $data = htmlspecialchars($data);
   return $data;
}

而不是

if ($_SERVER["REQUEST_METHOD"] == "POST") {
   $name = test_input($_POST["name"]);
   $email = test_input($_POST["email"]);
   $website = test_input($_POST["website"]);
   $comment = test_input($_POST["comment"]);
   $gender = test_input($_POST["gender"]);
}