Question

Possible Duplicate:
Regular Expression matching for entire string

On my form page, I am trying to make it only accept alphanumeric characters for my username and password and require that they be from 6 to 15 characters. When I type in invalid data, it will insert it into the database rather than throw the user error that I defined in my CheckAlNum function.

functions.php

function checkAlNum($whichField) 
{
    if (preg_match('/[A-Za-z0-9]+/', $_POST[$whichField])){
        if ( (!count(strlen($whichField) >= 6)) OR (!count(strlen($whichField) <= 15 ))) {
            $message1 = '<p> Username and password must be between 6 and 15 characters </p>';
                return user_error($message1);
        }
        else{       
            return true;
        }           
    }

    else {
        $message = '<p>Username and password can only be numbers or letters</p>';
            return user_error($message);
     }


 } 

Form.php

        if (count($_POST) > 0) {

           //Validate the inputs
            $errorMessages = array();

            //Validate the username   
            $item5 = checkAlNum('username');
            if($item5 !== true) {
                $errorMessages[] = $item5;
            }

            //Validate the password
            $item6 = checkAlNum('password');
            if($item6 !== true) {
                $errorMessages[] = $item6;
            }

            //Validate the firstName and lastName
            $item1 = checkNameChars('firstName');
            if ($item1 !== true) {
                $errorMessages[] = $item1;

            }

            $item2 = checkNameChars('lastName');
            if ($item2 !== true) {
                $errorMessages[] = $item2;

            }   

            //Validate the office name
            $item3 = checkOfficeChars('office');
            if ($item3 !== true) {
                $errorMessages[] = $item3;

            }

            //Validate the phone number 
            $item4 = validate_phone_number('phoneNumber');
            if($item4 !== true) {
                $errorMessages[] = $item4;
            }  


            //Check to see if anything failed
            if (count($errorMessages) == 0) {

                $newEmployee = new Person;
                    $newEmployee -> insert();

            }

            else { //Else, reprint the form along with some error messages
                echo "<h2><span>Error</span>: </h2>";

                foreach($errorMessages as $msg) {
                    echo "<p>" . $msg . "</p>";
              }
            }
        }  

        ?>

I’ve tried playing around with the nesting of the if-else statements of the checkAlNum function and also the regex (although I’m pretty sure the regex is right). Maybe I’m just missing something really silly?

Answer 1

function checkAlNum($whichField) 
{
    if (preg_match('/^[a-z0-9]{6,15}$/i', $_POST[$whichField])) {
        return true;          
    }
    else {
        $message = '<p>Username and password can only be numbers or letters, 6-15 characters long</p>';
            return user_error($message);
     }
}

Without the ^ and $ anchors, your regex only checks whether there are alphanumerics anywhere in the field, not that the whole thing is alphanumeric. And changing + to {6,15} implements the length check here, so you can remove that extra check in your code.