PHP 表单验证实例 - 自学教程(runoops.com)

<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>PHP 表单验证 实例 - 自学教程(runoops.com)</title>
    <style>
        .error {
            color: #FF0000;
        }
    </style>
</head>

<body>

<?php
    // 定义变量并默认设置为空值
    $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"]);
            // 检测名字是否只包含字母跟空格
            if (!preg_match("/^[a-zA-Z ]*$/", $name)) {
                $nameErr = "只允许字母和空格";
            }
        }

if (empty($_POST["email"])) {
            $emailErr = "Email is required";
        } else {
            $email = test_input($_POST["email"]);
            // 检测邮箱是否合法
            if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/", $email)) {
                $emailErr = "非法邮箱格式";
            }
        }

if (empty($_POST["website"])) {
            $website = "";
        } else {
            $website = test_input($_POST["website"]);
            // 检测 URL 地址是否合法
            if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i", $website)) {
                $websiteErr = "非法的 URL 的地址";
            }
        }

if (empty($_POST["comment"])) {
            $comment = "";
        } else {
            $comment = test_input($_POST["comment"]);
        }

if (empty($_POST["gender"])) {
            $genderErr = "性别是必需的";
        } else {
            $gender = test_input($_POST["gender"]);
        }
    }

function test_input($data)
    {
        $data = trim($data);
        $data = stripslashes($data);
        $data = htmlspecialchars($data);
        return $data;
    }
    ?>

<h2>PHP 表单验证实例</h2>
    <p><span class="error">* 必需字段。</span></p>
    <form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>">
        名字: <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>
        网址: <input type="text" name="website">
        <span class="error"><?php echo $websiteErr; ?></span>
        <br><br>
        备注: <textarea name="comment" rows="5" cols="40"></textarea>
        <br><br>
        性别:
        <input type="radio" name="gender" value="female">女
        <input type="radio" name="gender" value="male">男
        <span class="error">* <?php echo $genderErr; ?></span>
        <br><br>
        <input type="submit" name="submit" value="Submit">
    </form>

<?php
    echo "<h2>您输入的内容是:</h2>";
    echo $name;
    echo "<br>";
    echo $email;
    echo "<br>";
    echo $website;
    echo "<br>";
    echo $comment;
    echo "<br>";
    echo $gender;
    ?>

</body>

</html>