Checking "required" fields.

[trepid_jesse]

I may be mistaken, but I thought I had read some tutorial at this site on how to make a form that checks the "required" fields are indeed filled out. I've tried looking on my own, but I haven't come up with much -- perhaps I'm just overlooking it?

Could someone point me in the right direction?

[Haleden]

Well, you could check for the required fields using JavaScript, and it would also be a good idea to check using PHP, because forms can be easily bypassed. You could probably find the JavaScript version at http://www.dynamicdrive.com. The PHP would be simple:

foreach ($_POST as $k => $v) {
    if ($v == '') {
    echo 'Empty field: ', $k, '<br>';
    $missingfield = 'true';
    }
}

if ($missingfield == 'true') {
//put any bottom includes here if necessary
exit;
} 

The above script would check all the fields to make sure they were filled out. If you only need certain fields filled out, you could do this:

$required = array('put','required','field','names','here');

foreach ($_POST as $k => $v) {
    if ($v == '' && in_array($k, $required)) {
    echo 'Empty field: ', $k, '<br>';
    $missingfield = 'true';
    }
}

if ($missingfield == 'true') {
//put any bottom includes here if necessary
exit;
} 

Tested and approved.

[N9ne]

I use this:

http://www.dynamicdrive.com/dynamici...uiredcheck.htm

Works very well and is customizable.

[Dr Livingston]

Personally don't see the point of using Javascript for checking FORMs nowadays... Spent a bit of time getting it right first time with PHP That and I'm lazy to implement Javascript with Xsl stylesheets...

[koomann]

Couldn't you just make it a required field like this?

if ($_POST['something']=="" || $_POST['else']=="") {
echo "You forgot.";
} 

[Haleden]

Pah, of course you could, but I think the functions I supplied were much more efficient =P. Especially if you are dealing with a lot of POST elements...

[trepid_jesse]

So, I was incorrect in thinking that there was a sitepoint tutorial that covered this matter?

I'm almost positive it was one of the articles a few months ago.

Anywho, I'd rather accomplish this task in PHP rather than Java.

[Ghz]

I liked the method that Haleden used. Thanx

[Haleden]

Woo! *does a dance*

[mattjacob]

foreach ($_POST as $k => $v) {
    if ($v == '') {
    echo 'Empty field: ', $k, '<br>';
    $missingfield = 'true';
    }
}

if ($missingfield == 'true') {
//put any bottom includes here if necessary
exit;
} 

I would use a Boolean for true (that's what they're for, after all) and also trim() the value before checking it.

foreach ($_POST as $k => $v)
{
    if (trim($v) == '') 
    {
        echo 'Empty field: '.$k.'<br>';
        $missingfield = true;
    }
}

if ($missingfield) 
{
    //put any bottom includes here if necessary
    exit;
} 

[denny]

I just happened to have the same problem and the PHP examples work great. I do have one question. How would I go about having it tell the viewer which field is not completed without giving them the field name.

Example:

Field name is "firstname". The above code displays this.
How could I get it to say "First Name" instead.

I know this is probably a simple thing but I'm still a newbe to PHP. I have tried renaming the fields but that doesn't seem to help.

Thanks

[frezno]

... but I think the functions I supplied were much more efficient =P. Especially if you are dealing with a lot of POST elements...

they definitly are. You just may run into problems if you want an error message referring to the appropriate field where there's the wrong/missing input, i guess.

[Amit]

Ok, another aproach ...
If the form has few fields say less then 10, I use something like this ...

if (!empty($_POST))
{
    $sErrMsg .= ( empty($email) ? "Email is empty.\n" : '' )
    . ( !verify_email($email) ? "Email is invalid.\n" : '' )
    . ( empty($username) ? "Username is empty.\n" : '' )
    . ( empty($comments) ? "Comments are empty.\n" : '' );
    // and so on and so forth ...

    if (empty($sErrMsg))          // Check if there were errors
    {
        // Do some work if no error ....
    }
} 

Ok, the reason, I use this
1. I can validate the data along side checking for the empty fields (as shown in email). And the validation can be done on any condition, not just field being empty.
2. I can have the messags generated against the empty field, that I can display to the user.
3. I can further check whether there were any errors, and to proceed accordingly.

If you have more variables then say 10, it would be advise to use a function, with possibly arrays ...

HTH!

[denny]

If you only need certain fields filled out, you could do this:

$required = array('put','required','field','names','here');

foreach ($_POST as $k => $v) {
if ($v == '' && in_array($k, $required)) {
echo 'Empty field: ', $k, '<br>';
$missingfield = 'true';
}
}

if ($missingfield == 'true') {
//put any bottom includes here if necessary
exit;
} 

Tested and approved.

This works great for what I need. I only have 3 required fields. The problem is it gives the field name "Empty field: fname". How can I make it more user friendly and say "Empty field: First Name" instead? Can I assign the same field name 2 different variables and still have it work? I'm new to PHP and everything I have tried causes the email script not to work.

Any help would be appreciated..

Thanks

[denny]

Does anyone have any ideas?

[Amit]

You can try this ....

$req = array(
    'put' => 'Put your Field',
    'required' => 'Top Case',
    'field' => 'lower case', 
    'names' => 'Or Whatever message',
    'here' => 'Here'
);
$required = array_keys($req);

foreach ($_POST as $k => $v) 
{
  if ($v == '' && in_array($k, $required)) 
  {
    echo 'Empty field: ', $req[$k], '<br>';
    $missingfield = 'true';
  }
}

if ($missingfield == 'true') {
//put any bottom includes here if necessary
exit;
} 

HTH!

[denny]

Thanks Amit..

It works great!!! I would have never thought about an array to do it.. I'm learning something new everyday..

[koomann]

I'm learning something new everyday..

Mmm, you're not the only one.

Trust me!

[Amit]

Yeah, we all learn a littlebit new everyday ..

[Raskolnikov]

Hey, i dig the script, but how can i create a link back to the form with the fields that were initially filled in still filled in.

[Amit]

Process the data in the same file which contains the PHP and the form

[jadmadi]

<?
$field = stripslashes($_REQUEST['field']);
if (empty ($field)) {
$error .= "Field name";
}

//then print all errors
print $error;
?>

[lieut_data]

Hey, i dig the script, but how can i create a link back to the form with the fields that were initially filled in still filled in.

I usually implement some basic error handling functionality (with return values), like this:

<?php
if (isset($_POST['submit'])) {
   //Check form's validity
   foreach ($_POST as $key=>$element) {

   //Default empty fields
   if (trim($element) == '')
      $errors[$key] = 'Please enter a ' . str_replace('_', ' ', $key);
   }

   //Specialty values
   if (!is_email($_POST['email'])) {
      $errors['email'] = 'Please enter a valid e-mail address';
   }

   //If errors, redirect back
   if (is_array($errors)) {
      foreach ($errors as $error)
         $error_string .= '&error[]=' . urlencode($error);
      foreach ($_POST as $key=>$element)
         $previous_values .= "&$key=" . urlencode($element);
      redirect ($_SERVER['PHP_SELF'] . '?' . $error_string . $previous_values);
}

//Otherwise success!

And in the form:

<form name="contact" method="POST" action="<?php echo $_SERVER['PHP_SELF']; ?>">
    <strong>
    <?php 
        if (is_array($_GET['error']))
           foreach ($_GET['error'] as $error)
            echo $error . '<br />';
        ?>
    </strong>
    
Your Name: <input name="name" type="text" value="<?php echo $_GET['name']; ?>"><br />
<br />
Your Email: <input name="email" type="text" value="<?php echo $_GET['email']; ?>">
<!--...-->
</form>