Validating blank variable with Form Submissions?

[RiBlanced]

Is there a way to validate a blank variable submitted via Forms?

For example I can validate whether or not the variable "is_set" or "empty" but if I submit a form without putting any values in at all I can't tell what the are set to and therefor have no way of controling the output.

Note: I have checked and made sure they are either is_set, empty, or null. Non of those has worked.

[archangel_617b]

Do you meen form inputs that are submitted without a value? Like if someone tries to login without entering their password? I just check them like this:

// Assume we have a text field name 'user' and a password field named 'pass'
if (!$_POST['user'])
    die('No username provided.');

if (!$_POST['pass'])
    die('No password provided.');

[RiBlanced]

Truly...thank you. I modified your example just a little but that was basically what I was looking for.

[Rohan_Hill]

I personally wouldn't use the ! operator for that, this might not be all that relevant to your application but if someone enters "0" into your field, it would evaluate to false.

I'd use if ($POST['user'] === NULL || $POST['user'] === "")
I'd advise you use both of those since depending on the server, empty forms are sometimes not defined at all (NULL), or sometimes set to "" 🙂

[RiBlanced]

I tried that out and YES is does seem to think that a value of 0 means that no value was entered at all. Thanks for the tip. 😉

[Weedpacket]

Though you should still verify that the variable isset() before trying to use it (and perhaps set it to '' if it's not). Some PHP installations have their error reporting cranked up enough that testing the values of unset variables raises a notice.