如果发生错误，我在保存写在文本字段中的值时遇到问题。我有4个文本字段，如果1为空，它需要显示一个新表单，其中包含一条错误消息和上一个文件的文本字段中的输入。
我想这是我作业_2.php的最后一部分，它错了。
assignment_1.php
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<form action="sendit.php" method="get">
<input type="text" name="name" placeholder="name"/>
<br>
<input type="text" name="adress" placeholder="adress"/>
<br>
<input type="text" name="city" placeholder="city"/>
<br>
<input type="text" name="zip" placeholder="zip"/>
<br>
<input type="submit" />
</form>
<br>
</body>
</html>
sendit.php
<?php
$name = $_GET['name'];
$adress = $_GET['adress'];
$city = $_GET['city'];
$zip = $_GET['zip'];
if (!isset($_GET['name']) || $_GET['name'] == '') {
header("Location: assignment_2.php?errmsg=1");
exit;
}
else {
header("Location: assignment_2.php?errmsg=1&name=$name");
}
if (!isset($_GET['adress'])|| $_GET['adress'] == '') {
header("Location: assignment_2.php?errmsg=2&adress=$adress");
exit;
}
else {
header("Location: assignment_2.php?errmsg=1&adress=$adress");
}
if (!isset($_GET['city'])|| $_GET['city'] == '') {
header("Location: assignment_2.php?errmsg=3&city=$city");
exit;
}
else {
header("Location: assignment_2.php?errmsg=1&city=$city");
}
if (!isset($_GET['zip'])|| $_GET['zip'] == '') {
header("Location: assignment_2.php?errmsg=4&zip=$zip");
exit;
}
else {
header("Location: assignment_2.php?errmsg=4&zip=$zip");
}
echo $name . "<br>" . $adress . "<br>" . $city . "<br>" . $zip
?>
assignment_2.php
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<?php
// 1.0 Create a contactform containing name, address, city, zipcode
// Send it to a form handler
// If any of the form fields are not filled out, return to this page and
// display an error containing information on how to prevent the error
// 1.1 Preserve the input for the user
?>
<?php
if (isset($_GET['errmsg'])) {
$err = $_GET['errmsg'];
switch ($err) {
case 1:
$err_msg = 'Missing navn';
break;
case 2:
$err_msg = 'Missing adress';
break;
case 3:
$err_msg = 'Missing city';
break;
case 4:
$err_msg = 'missing zip';
break;
default:
$err_msg = 'I just dont like you';
break;
}
echo '<div class="error">' . $err_msg . '</div>';
}
?>
<form action="sendit.php" method="get">
<input type="text" name="name" placeholder="name" <?php
if (isset($_GET['name'])) echo 'value="' .$_GET['name'] .'"';
?> />
<br>
<input type="text" name="adress" placeholder="adress" <?php
if (isset($_GET['adress'])) echo 'value="' .$_GET['adress'] .'"';
?>/>
<br>
<input type="text" name="city" placeholder="city" <?php
if (isset($_GET['city'])) echo 'value="' .$_GET['city'] .'"';
?>/>
<br>
<input type="text" name="zip" placeholder="zip" <?php
if (isset($_GET['zip'])) echo 'value="' .$_GET['zip'] .'"';
?>/>
<br>
<input type="submit" />
</form>
</body>
</html>
我可能会处理第一个客户端验证，所以在所有输入都填写好之前，表单不会提交，然后我会进行一些服务器端验证和清理。顺便说一句，你不需要有任务。
保持简单！对于初学者来说，试着只处理一个文件，并将错误放入一个数组中。
然后试着缩短你的代码，并且永远不要"复制和粘贴"代码。
在现代网站上，开发人员使用框架来验证表单，继续玩这个，直到它像你想要的那样工作，然后看看Symfony或Zend Framework表单验证。
<?php
$errors = array();
if (isset($_GET['submitted'])) {
if (!isset($_GET['name']) || $_GET['name'] == '')
$errors[] = 'Missing navn'
if (!isset($_GET['adress']) || $_GET['adress'] == '')
$errors[] = 'Missing navn'
if (!isset($_GET['city']) || $_GET['city'] == '')
$errors[] = 'Missing navn'
if (!isset($_GET['zip']) || $_GET['zip'] == '')
$errors[] = 'Missing navn'
}
?><!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<?php
if (count($errors) !== 0)
echo '<div class="error">' . implode("<br>", $errors) . '</div>';
?>
<form action="" method="get">
<input type="hidden" name="submitted" value="1" />
<input type="text" name="name" placeholder="name" value="<?php echo isset($_GET['name']) ? $_GET['name'] : '' ?>" />
<br>
<input type="text" name="adress" placeholder="adress" value="<?php echo isset($_GET['adress']) ? $_GET['adress'] : '' ?>" />
<br>
<input type="text" name="city" placeholder="city" value="<?php echo isset($_GET['city']) ? $_GET['city'] : '' ?>" />
<br>
<input type="text" name="zip" placeholder="zip" value="<?php echo isset($_GET['zip']) ? $_GET['zip'] : '' ?>" />
<br>
<input type="submit" />
</form>
<br>
</body>
</html>