i'm have a form that's posting to another page. But i'm trying to stay on the same page if the fields are null and display all the error messages instead of going into my action page. Is there a way around this? i have tried using javascript to stop the form from submitting however it is not displaying the error messages. I want to know if this do-able using only php? I know i could just put everything in a page but i'm curious which way is more efficient or how it's suppose to be done? thanks a million
register.php
<?php include 'formCheck.php'; ?>
<form method="post" action="add.php">
<div class="textbox">
<label for="uname">Username:</label>
<span class="error">* <?php echo $uerror;?></span>
<input type="text" name="username" placeholder="Username">
</div>
add.php
<?php
require_once "db.php";
if ( !empty($_POST['username'])) {
$u = mysqli_real_escape_string($db, $_POST['username']);
$sql= "INSERT INTO users (username) VALUES ('$u')";
echo "<pre>\n$sql\n</pre>\n";
mysqli_query($db,$sql);
echo 'Success -Continue...';
return;
}
formCheck.php
<?php
$uerror = '';
if ($_SERVER["REQUEST_METHOD"] == "POST") {
if (empty($_POST["username"])) {
$uerror = "Username is required";
}
}
?>
You can use jQuery to help you with this task.
$( "form" ).submit(function( event ) {
event.preventDefault(); //prevents from reloading
// your stuff
return false;
});
I have a form that has action="file.php" , That PHP file has the cheeks and outputs , I want these outputs to be on the same form page.
The form exists in an html file :
<form class="" method="post" action="file.php">
<!-- Some Form Fields -->
</form>
The file.php contains some checks and outputs like:
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$name = $_POST['name'];
if ( empty($name){
echo "Name can't be empty.";
}
}
How to show these outputs on the same page next to the form?
If you are posting to the same page, you can echo errors on the same page & retain the posted data no problem with something like this.
in php
$errors = []
if (empty($name){
$errors['name'] = "Name can't be empty.";
}
... and on the form
<php if (isset($errors['name'])) echo $errors['name']; ?>
<input name='name' value="<?php if (isset($_POST['name'])) echo $_POST['name']; ?>"></input>
If you are posting to a different url, then you will have to redirect back to the form page or include the form page, and pass the $errors and the $_POST data.
Do everything in the same file.php:
<form class="" method="post" action="file.php">
<!-- Some Form Fields -->
</form>
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$name = $_POST['name'];
if ( empty($name){
echo "Name can't be empty.";
}
}
If you're trying to have that validation in the same form file, let's call it 'form.html', first rename it to 'form.php'. Then add the <?php ?> tags above all the html code, and write your code there.
For that to work, you need to have to left empty the action attribute in form
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$name = $_POST['name'];
if ( empty($name){
echo "Name can't be empty.";
}
}
?>
<!-- Some HTML Code-->
<form class="" method="post" action="">
<!-- Some Form Fields -->
</form>
I hope this answer your question about having the code in the same page, but if what you're trying to do is check if field is empty, i recommend you use the 'required' attribute in the html form's input.
So I am trying to prevent form resubmission using sessions
and this is my code :
<?php
session_start();
if(isset($_GET['unid']))
{
if ($_GET['unid']==$_SESSION["uid"])
{
echo "Form is Submited do something";
}
else
{
echo "no you can't do that";
}
}
$unid = md5(uniqid());
$_SESSION["uid"] = $unid;
?>
<form method="GET">
<input name="name" value="test">
<input name="unid" value="<?php echo $unid;?>">
<input type="submit">
and it works ...but if the user opens another tab then it will break so how can I fix it ?
I'm not sure about this but may be assigning a new global session variable will work, say $_SESSION['checkSub']. So once the form is submitted, set it to 1 or true and only let form submission if it isn't 1 or false.
You can check to see if the unid is set in the session before generating a new unique id. See updated code below:
<?php
session_start();
if(isset($_GET['unid']))
{
if (isset($_SESSION['unid']) && $_GET['unid']==$_SESSION['unid'])
{
//form has been submitted with matching unid - process it as needed
unset($_SESSION['unid']);
}
else
{
// Form was resubmitted or some other logic error
}
}
$unid = ''; //declare here for good scope
if (isset($_SESSION["unid"])) {
$unid = $_SESSION["unid"];
}
else {
$unid = md5(uniqid());
$_SESSION["unid"] = $unid;
}
?>
<form method="GET">
<input name="name" value="test">
<input name="unid" value="<?php echo $unid;?>">
<input type="submit">
Rather than using form method GET, try to use POST. It will work for you. The $_POST array will only have data in it when form is submitted, so you should not have to use the session to know whether form is submitted or not.
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 = "comments#myemail.com";
$yourname = check_input($_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.
Have one function or code block that outputs the form and is aware of your error messages and has access to the previous form input (if any). Typically, this can be left outside of a function and can be the last block of code in your PHP script.
Set up an array for error messages (e.g. $errors = array()). When this array is empty, you know there were no errors with the submission
Check to see if the form was submitted near the top of your script before the form is output.
If the form was submitted, validate each field one at a time, if a field contained an error, add the error message to the $errors array (e.g. $errors['password'] = 'Passwords must be at least 8 characters long';)
To re-populate the form inputs with the previous values, you have to store the entered values somewhere (you can either just use the $_POST array, or sanitize and assign the $_POST values to individual variables or an array.
Once all the processing is done, you can check for any errors to decide whether the form can be processed at this point, or needs new input from the user.
To do this, I typically do something like if (sizeof($errors) > 0) { // show messages } else { // process form }
If you are re-displaying the form, you simply need to add a 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 functions
With those things in place, here is some re-work of your form to do that:
<?php
$myemail = "comments#myemail.com";
$errors = array();
$values = array();
$errmsg = '';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
foreach($_POST as $key => $value) {
$values[$key] = trim(stripslashes($value)); // basic input filter
}
if (check_input($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 $errmsg; ?>
</p>
<?php endif; ?>
<p>Name: <input type="text" name="yourname" value="<?php echo htmlspecialchars(#$values['yourname']) ?>" /></P>
<P>Email: <input type="text" name="email" value="<?php echo htmlspecialchars(#$values['email']) ?>" /></p>
<P>Phone: <input type="text" name="phone" value="<?php echo htmlspecialchars(#$values['phone']) ?>"/></p><br />
<P>Subject: <input type="text" style="width:75%;" name="subject" value="<?php echo htmlspecialchars(#$values['subject']) ?>" /></p>
<p>Comments:<br />
<textarea name="comments" rows="10" cols="50" style="width: 100%;"><?php echo htmlspecialchars(#$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.
The simplest option is to use a form validation library. PHP's filter extension, for example, offers validation and sanitization for some types, though it's not a complete solution.
If you insist on implementing it yourself, one issue you'll have to consider is what counts as the order: the order of the elements in the form or the order of the user input in $_POST. On most browsers, these should be the same, but there's no standard that enforces this. If you want to go off of form order, you'll need to define the form structure in one place, and use that information to do things like generating or validating the form (a consequence of the Don't Repeat Yourself (DRY) principle). Iterating over the appropriate structure will give you the order you desire: looping over the form gives you form order, whereas looping over $_POST gives you user input order.
It looks like you want to more than simply validate the data; you also want to prepare it for use, a process called "sanitization".
When it comes to sanitization, define different kinds of sanitizers, rather than a single check_input function. Specific sanitizers could be functions, or objects with an __invoke method. Create a map of form fields to sanitizers (for example, an array of input name to sanitizer callbacks). The order of the elements in the mapping sets the order of the sanitization; if you use a single structure to define the form information, the display order and sanitization order will thus be the same.
Here's a very broad outline:
# $fields could be form structure or user input
foreach ($fields as $name => $data) {
# sanitize dispatches to the appropriate sanitizer for the given field name
$form->sanitize($name, $data);
# or:
//sanitize($name, $data);
# or however you choose to structure your sanitization dispatch mechanism
}
As for setting an input's value to the user-supplied data, simply output the element value when outputting the element. As with all user input (really, all formatted output), properly escape the data when outputting it. For HTML attributes, this means using (e.g.) htmlspecialchars. Note you should only escape outgoing data. This means your sanitization functions shouldn't call htmlspecialchars.
You can improve usability by placing each error next to the corresponding input, adding an "error" class to the element and styling the "error" class to make it stand out. Improve accessibility by wrapping <label> elements around the label text.
Use this structure of script:
<?php
$errors = array();
if (isset($_POST['send'])) {
// check data validity
if (!mailValid($_POST['email']))
$errors[] = 'Mail is not valid';
...
// send data by email
if (!$errors) {
// send mail and redirect
}
}
?>
<html>
...
<?php
if ($errors) {
// display errors
foreach ($errors as $error) {
echo "$error<br />";
}
}
?>
<form ...>
...
Email: <input type="text" name="email" value="<?php echo isset($_POST['email']) ? htmlspecialchars($_POST['email']) : '' ?>" />
...
</form>
...
</html>
You could always do it like this, using filter_var and in_array checks:
<?php
$myemail = "comments#myemail.com";
//Pre made errors array
$errors=array('name'=>'Enter Your name',
'email'=>'Please enter valid email',
'phone'=>'Please enter valid phone number',
'subject'=>'Please enter valid subject, more then 10 chars',
'comment'=>'Please enter valid comment, more then 10 chars');
//Allowed post params and its validation type
$types = array('name'=>'string',
'email'=>'email',
'phone'=>'phone',
'subject'=>'string',
'comment'=>'string');
//A simple validation function using filter_var
function validate($value,$type){
switch ($type){
case "email":
return ((filter_var($value, FILTER_VALIDATE_EMAIL))?true:false);
break;
case "phone":
return ((preg_match("/^[0-9]{3}-[0-9]{4}-[0-9]{4}$/", $value))?true:false);
break;
case "string":
return ((strlen($value) >=10 )?true:false);
break;
default:
return false;
break;
}
}
//If forms been posted
if(!empty($_POST) && $_SERVER['REQUEST_METHOD'] == 'POST'){
//Assign true, if all is good then this will still be true
$cont=true;
$error=array();
foreach($_POST as $key=>$value){
//if key is in $types array
if(in_array($key,$types)){
//If validation true
if(validate($value, $types[$key])==true){
$$key=filter_var($value, FILTER_SANITIZE_STRING);
}else{
//Validation failed assign error and swithc cont to false
$error[$key]=$errors[$key];
$cont=false;
}
}
}
}
if($cont==true && empty($error)){
//Send mail / do insert ect
}else{
//Default to form
?>
<!doctype html>
<html>
<body>
<form action="" method="post">
<p>Name: <input type="text" name="name" value="<?=#htmlentities($name);?>"/> <?=#$error['name'];?></P>
<P>Email: <input type="text" name="email" value="<?=#htmlentities($email);?>" /> <?=#$error['email'];?></p>
<P>Phone: <input type="text" name="phone" value="<?=#htmlentities($phone);?>"/> <?=#$error['phone'];?></p><br />
<P>Subject: <input type="text" style="width:75%;" name="subject" /> <?=#$error['subject'];?></p>
<p>Comments: <?=#$error['comment'];?><br />
<textarea name="comment" rows="10" cols="50" style="width: 100%;"><?=#htmlentities($comment);?></textarea></p>
<p><input type="submit" value="Submit"></p>
</form>
</body>
</html>
<?php
}?>
I am generating form and handling the submit event in the same file.
If user has not entered the title, I want to display the form again and include an error message (e.g. "You forgot the title.").
That means that I have to duplicate code twice - once to diplay empty form and second to display form with body and ask user to enter title:
<?php if(strlen(strip_tags($_POST['posttitle'])) == 0):
// Display the form with question body that user has entered so far and ask user to enter title.
?>
<label for="title"><b>Title:</label><br/>
<input type="text" name="posttitle" id="posttitle" />
<?php endif;?>
<?php elseif ( 'POST' == $_SERVER['REQUEST_METHOD'] && !empty( $_POST['action']) && $_POST['action'] == 'post') : ?>
<!-- Everything ok - insert post to DB -->
<?php else :
// just display form here (again ouch!)
<label for="title"><b>Title:</label><br/>
<input type="text" name="posttitle" id="posttitle" />
?>
I would do it like this:
If REQUEST_METHOD is POST I will validate the input and collect messages in an array ($errors in my code).
Then I would just print the form and if there was an error the code will print it.
<?php
$errors = array();
function print_value_for($attr) {
if (isset($_POST[$attr]))
echo $_POST[$attr];
}
function print_error_for($attr) {
global $errors;
if (isset($errors[$attr]))
echo $errors[$attr];
}
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
// do validation here and add messages to $errors
// like $errors['posttitle'] = "The title you entered is bad bad bad";
if (empty($errors)) {
// update database and redirect user
}
}
?>
<!-- display the form and print errors if needed -->
<form>
<?php print_error_for('posttitle'); ?>
<input name="posttitle" type="text" value="<?php print_value_for('posttitle') ?>">
<?php print_error_for('postauthor'); ?>
<input name="postauthor" type="text" value="<?php print_value_for('posttitle') ?>">
<?php print_error_for('postbody'); ?>
<textarea name="postbody">
<?php print_value_for('posttitle') ?>
</textarea>
<input type="submit">
</form>
PS. Consider using MVC to separate code and templates.
Here is a quick way to do that.
<form>
<input type="text" name="title" value="<?php echo $_REQUEST['title']; ?>"/>
<input type="text" name="field_a" value="<?php echo $_REQUEST['field_a']; ?>"/>
....
</form>
But I can also advise you to display a var called $title which is the result of a check on $_REQUEST['title].
You could use an output buffer to grab the form and then assign it to a variable like so:
<?php
ob_start();
include('path/to/your/form');
$form = ob_get_flush();
// then later you can just go
print $form;
?>
Hope this helps
When you display the form, use the possibly empty $_POST values as default field values for both the title and question body. If either is empty, the form will display the second time with the other already filled in:
<?php
$message = "";
if (empty($_POST['title'])) $message .= " Please enter a title.";
if (empty($_POST['body'])) $message .= " Please enter a body.";
?>
<form action='me.php'>
<input name='title' type='text' value='<?php if (!empty($_POST['title'])) echo htmlentities($_POST['title'], ENT_QUOTES); ?>' />
<textarea name='body'><?php if (!empty($_POST['body'])) echo $_POST['body']; ?></textarea>
</form>
Read this MVC
Your can write form in view, handler in controller, and business logic in model