I have an email form that checks three fields, name, valid email and comments. But the way it's set up now, since name and comments are in one function it first checks name and comments even if email is not valid, how can I re-write it so it checks the fields in order. Also, I would like to re-display the fields that have no errors, so the user doesn't have to type again. Please help. Thanks
<?php
$myemail = "[email protected]";
$yourname = check_input($_POST['yourname'], "Enter your name!");
$email = check_input($_POST['email']);
$phone = check_input($_POST['phone']);
$subject = check_input($_POST['subject']);
$comments = check_input($_POST['comments'], "Write your comments!");
if (!preg_match("/([\w\-]+\@[\w\-]+\.[\w\-]+)/", $email))
{
show_error("Enter a valid E-mail address!");
}
exit();
function check_input($data, $problem='')
{
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
if ($problem && strlen($data) == 0)
{
show_error($problem);
}
return $data;
}
function show_error($myError)
{
?>
<!doctype html>
<html>
<body>
<form action="myform.php" method="post">
<p style="color: red;"><b>Please correct the following error:</b><br />
<?php echo $myError; ?></p>
<p>Name: <input type="text" name="yourname" /></P>
<P>Email: <input type="text" name="email" /></p>
<P>Phone: <input type="text" name="phone" /></p><br />
<P>Subject: <input type="text" style="width:75%;" name="subject" /></p>
<p>Comments:<br />
<textarea name="comments" rows="10" cols="50" style="width: 100%;"></textarea></p>
<p><input type="submit" value="Submit"></p>
</form>
</body>
</html>
<?php
exit();
}
?>
First off, I would suggest you validate ALL of the fields at once, and display all appropriate error messages on the form. The primary reason is that it can be bad user experience if they have to submit your form a whole bunch of times because they have to address one error at a time. I'd rather correct my email address, password, comments, and selection in one try instead of fixing one at a time just to reveal what the next error is.
That said, here are some pointers on validating the form like you want. This is typically how I approach a form doing what you want to do. This assumes your form HTML and form processor (PHP) are together in the same file (which is what you have now). You can split the two, but the methods for doing that can be a bit different.
$errors = array()
). When this array is empty, you know there were no errors with the submission$errors
array (e.g. $errors['password'] = 'Passwords must be at least 8 characters long';
)$_POST
array, or sanitize and assign the $_POST
values to individual variables or an array.if (sizeof($errors) > 0) { // show messages } else { // process form }
value=""
attribute to each form element and echo the value that was submitted by the user. It is very important to escape the output using htmlspecialchars() or similar functionsWith those things in place, here is some re-work of your form to do that:
<?php
$myemail = "[email protected]";
$errors = [];
$values = ['yourname' => '','email' => '','phone' => '','subject' => '','comments' => '']
$errmsg = '';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
foreach($_POST as $key => $value) {
$values[$key] = trim($value); // basic input filter
}
if (check_input($values['yourname']) == false) {
$errors['yourname'] = 'Enter your name!';
}
if (check_input($values['email']) == false) {
$errors['email'] = 'Please enter your email address.';
} else if (!preg_match('/([\w\-]+\@[\w\-]+\.[\w\-]+)/', $values['email'])) {
$errors['email'] = 'Invalid email address format.';
}
if (check_input($values['comments']) == false) {
$errors['comments'] = 'Write your comments!';
}
if (sizeof($errors) == 0) {
// you can process your for here and redirect or show a success message
$values = array(); // empty values array
echo "Form was OK! Good to process...<br />";
} else {
// one or more errors
foreach($errors as $error) {
$errmsg .= $error . '<br />';
}
}
}
function check_input($input) {
if (strlen($input) == 0) {
return false;
} else {
// TODO: other checks?
return true;
}
}
?>
<!doctype html>
<html>
<body>
<form action="<?php echo $_SERVER['PHP_SELF'] ?>" method="post">
<?php if ($errmsg != ''): ?>
<p style="color: red;"><b>Please correct the following errors:</b><br />
<?php echo $errmsg; ?>
</p>
<?php endif; ?>
<p>Name: <input type="text" name="yourname" value="<?= htmlspecialchars($values['yourname']) ?>" /></P>
<P>Email: <input type="text" name="email" value="<?= htmlspecialchars($values['email']) ?>" /></p>
<P>Phone: <input type="text" name="phone" value="<?= htmlspecialchars($values['phone']) ?>"/></p><br />
<P>Subject: <input type="text" style="width:75%;" name="subject" value="<?= htmlspecialchars($values['subject']) ?>" /></p>
<p>Comments:<br />
<textarea name="comments" rows="10" cols="50" style="width: 100%;"><?= htmlspecialchars($values['comments']) ?></textarea></p>
<p><input type="submit" value="Submit"></p>
</form>
</body>
</html>
I have a more advanced example which you can see here that may give you some guidance as well.
Hope that helps.