从 php 变量设置 html 文本框值

Question

我正在尝试根据会话数据为 html 注册表单中的文本框填写默认“值”字段。

如果用户在我的注册表单上犯了任何错误，它会将他们发回，我希望尽可能多地填写他们的数据，而不是将他们发送回普通表单以重新开始。

这是我的处理程序脚本检查：

// Let's get the text from the form,.

$username = mysql_real_escape_string($_POST['username']);
$password = mysql_real_escape_string($_POST['password']);
$password_check = mysql_real_escape_string($_POST['pwcheck']);
$email = mysql_real_escape_string($_POST['email']);
$spam_check = mysql_real_escape_string($_POST['checkit']); // spam check
$IP = $_SERVER['REMOTE_ADDR']; // log their ip

// set up some session data for mnistakes or spam or errors
$_SESSION['username'] = $username;
$_SESSION['email'] = $email;

// check for empty info

if ($username == NULL || $username == '') { // no username set
    header ("Location: register.php?p=un"); die;
}
if ($password == NULL || $password == '') { // no password set
    header ("Location: register.php?p=pw"); die;
}
if ($password_check == NULL || $password_check == '') { // no password check set
    header ("Location: register.php?p=pwchk"); die;
}
if ($email == NULL || $email == '') { // no email set
    header ("Location: register.php?p=em"); die;
}

// have we had Spam?

if (strlen($spam_check) > 0) { // spam bot alert
    header ("Location: http://www.google.co.uk");
    die ('You\'re naughty.');
}

// does password and check match?

if ($password != $password_check) { // no match
    $_SESSION['username'] = $username;
    $_SESSION['email'] = $email;
    header ("Location: register.php?p=pwnpc&email=".$email.""); die;
}

在我的表单页面上我正在做：

// check for empty fields and session data

if (isset($_SESSION['email'])) { // email session data set
$email_value = 'value = "'.$_SESSION['email'].'"';
} else { $email_value = 'placeholder="Email"'; }

$errors = mysql_real_escape_string($_GET['p']);

switch ($errors) { // something is empty
case "un": // no username set
    $pen_name = 'Pen Name missing!';
break;
case "pw": // no username set
    $password = 'Password missing!';
break;
case "pwchk": // no password check set
    $pw_check = 'Your passwords don\'t match!';
break;
case "em": // no username set
    $email = 'Email missing!';
break;
case "pwnpc": // passwords don't match
    $pw_mismatch = 'Passwords don\'t match!';
break;
}

及其自身的形式

<form action="register_handle.php" method="post">

<label>Choose a Pen Name</label><br /><?php echo $pen_name ?>
<p><input type="text" name="username" placeholder="Pen Name" autofocus required> </p>

<label>Choose a Password</label><br />
<p><input type="password" name="password" placeholder="Password" required> ---> <input type="password" name="pwcheck" placeholder="Password Confirm" required> <?php echo $password.$pw_check.$pw_mismatch ?></p>

<label>Email</label><br />

 <?php echo $email ?>

<p><input type="email" name="email" <?php echo $email_value ?> required></p>

<input id="checkit" type="text" name="checkit" maxlength="50" size="30">

<input type="submit" value=" Sign Me Up " name="submit" class="submit">

</form>

但我似乎无法恢复这些值。我敢肯定这一定很简单，但你能在这里看到问题吗？如您所见，到目前为止，我只在邮箱上尝试过，但无济于事。

Answer 1

您的<input> 字段中缺少value attribute：

<p><input type="email" name="email" value="<?php echo htmlentities($email_value) ?>" placeholder="Email" required></p>

这会破坏您想要使用的占位符，但无论如何它应该始终存在，因为如果您提供值，它将不会显示。