MachForm Community Forums » MachForm 3

1. tmparisi
   Member

   For those of you that take credit card numbers in your forms, here is a simple way to set up CC validation in your form that ultimately checks for several factors including, length, prefix, and mod-10 algorithm. The following code is adapted from: http://www.braemoor.co.uk/software/creditcard.php

   Open up your post_functions.php file in your include folder and find the following lines of code:

   if(!empty($row['form_redirect_enable'])){
    $form_redirect = $row['form_redirect'];
    }

   Right below this code, add the following verification script:

   //custom code
    //====================START CC Validation=======================
    if ($form_id == 15 || $form_id == 3 || $form_id == 4 || $form_id == 10 || $form_id == 11) {  //form numbers that have text fields that you want to perform CC validation
    if($form_id == 15)  //if form #15, set the credit card type dropdown and the credit card number fields according to the element numbers for that form
    {
    $cc_validate_id = 1;  //set credit card number field
    $cc_validate_type = 2;  //set credit card type field
    }
    if($form_id == 3)
    {
    $cc_validate_id = 28;
    $cc_validate_type = 17;
    }
    if($form_id == 4)
    {
    $cc_validate_id = 29;
    $cc_validate_type = 17;
    }
    if($form_id == 10)
    {
    $cc_validate_id = 28;
    $cc_validate_type = 17;
    }
    if($form_id == 11)
    {
    $cc_validate_id = 29;
    $cc_validate_type = 17;
    }
   
    $failcheck = 0;
    if (!empty($table_data['element_' . $cc_validate_id])) {
   
    if($table_data['element_' . $cc_validate_type] == 1) //check if credit card dropdown type is 1
    {
    $cardname = 'american express'; //if so, set $cardname equal to american express
    }
    else if($table_data['element_' . $cc_validate_type] == 2)
    {
    $cardname = 'visa';
    }
    else if($table_data['element_' . $cc_validate_type] == 3)
    {
    $cardname = 'mastercard';
    }
    else if($table_data['element_' . $cc_validate_type] == 4)
    {
    $cardname = 'discover';
    }
    else
    {
    $cardname = '';
    }
   
    $cardnumber = $table_data['element_' . $cc_validate_id]; //set $cardnumber equal to the credit card number entered by user
   
    $cards = array ( array ('name' => 'American Express',
   'length' => '15',
   'prefixes' => '34,37',
    'checkdigit' => true
    ),
    array ('name' => 'Discover',
   'length' => '16',
   'prefixes' => '6011,622,64,65',
    'checkdigit' => true
    ),
    array ('name' => 'MasterCard',
   'length' => '16',
   'prefixes' => '51,52,53,54,55',
    'checkdigit' => true
    ),
    array ('name' => 'VISA',
   'length' => '16',
   'prefixes' => '4',
    'checkdigit' => true
    ),
    array ('name' => 'VISA Electron',
   'length' => '16',
   'prefixes' => '417500,4917,4913,4508,4844',
    'checkdigit' => true
    )
    );
   
    $ccErrorNo = 0;
   
    $ccErrors [0] = "Unknown card type";
    $ccErrors [1] = "No card number provided";
    $ccErrors [2] = "Credit card number has invalid format";
    $ccErrors [3] = "Credit card number is invalid";
    $ccErrors [4] = "Credit card number is wrong length";
   
    // Establish card type
    $cardType = -1;
    for ($i=0; $i<sizeof($cards); $i++) {
   
    // See if it is this card (ignoring the case of the string)
    if (strtolower($cardname) == strtolower($cards[$i]['name'])) {
    $cardType = $i;
    break;
    }
    }
   
    // If card type not found, report an error
    if ($cardType == -1 && $failcheck == 0) {
    $errornumber = 0;
   $errortext = $ccErrors [$errornumber];
    $error_elements[$cc_validate_id] = $ccErrors [$errornumber];
    $failcheck = 1;
    }
   
    // Ensure that the user has provided a credit card number
    if (strlen($cardnumber) == 0 && $failcheck == 0) {
    $errornumber = 1;
   $errortext = $ccErrors [$errornumber];
    $error_elements[$cc_validate_id] = $ccErrors [$errornumber];
    $failcheck = 1;
    }
   
    // Remove any spaces from the credit card number
    $cardNo = str_replace (' ', '', $cardnumber); 
   
   // Check that the number is numeric and of the right sort of length.
    if (!preg_match("/^[0-9]{13,19}$/",$cardNo) && $failcheck == 0) {
    $errornumber = 2;
   $errortext = $ccErrors [$errornumber];
    $error_elements[$cc_validate_id] = $ccErrors [$errornumber];
    $failcheck = 2;
    }
   
    // Now check the modulus 10 check digit - if required
    if ($cards[$cardType]['checkdigit'] && $failcheck == 0) {
    $checksum = 0; // running checksum total
    $mychar = ""; // next char to process
    $j = 1; // takes value of 1 or 2
   
    // Process each digit one by one starting at the right
    for ($i = strlen($cardNo) - 1; $i >= 0; $i--) {
   
    // Extract the next digit and multiply by 1 or 2 on alternative digits.
   $calc = $cardNo{$i} * $j;
   
    // If the result is in two digits add 1 to the checksum total
    if ($calc > 9) {
    $checksum = $checksum + 1;
    $calc = $calc - 10;
    }
   
    // Add the units element to the checksum total
    $checksum = $checksum + $calc;
   
    // Switch the value of j
    if ($j ==1) {$j = 2;} else {$j = 1;};
    } 
   
   // All done - if checksum is divisible by 10, it is a valid modulus 10.
    // If not, report an error.
    if ($checksum % 10 != 0 && $failcheck == 0) {
    $errornumber = 3;
   $errortext = $ccErrors [$errornumber];
    $error_elements[$cc_validate_id] = $ccErrors [$errornumber];
    $failcheck = 3;
    }
    } 
   
   // The following are the card-specific checks we undertake.
   
    // Load an array with the valid prefixes for this card
    $prefix = explode(',',$cards[$cardType]['prefixes']);
   
    // Now see if any of them match what we have in the card number
   $PrefixValid = false;
   for ($i=0; $i<sizeof($prefix); $i++) {
    $exp = '/^' . $prefix[$i] . '/';
    if (preg_match($exp,$cardNo)) {
    $PrefixValid = true;
    break;
    }
    }
   
    // If it isn't a valid prefix there's no point at looking at the length
    if (!$PrefixValid && $failcheck == 0) {
    $errornumber = 3;
   $errortext = $ccErrors [$errornumber];
    $error_elements[$cc_validate_id] = $ccErrors [$errornumber];
    $failcheck = 3;
    }
   
    // See if the length is valid for this card
    $LengthValid = false;
    $lengths = explode(',',$cards[$cardType]['length']);
    for ($j=0; $j<sizeof($lengths); $j++) {
    if (strlen($cardNo) == $lengths[$j]) {
    $LengthValid = true;
    break;
    }
    }
   
    // See if all is OK by seeing if the length was valid.
   if (!$LengthValid && $failcheck == 0) {
    $errornumber = 4;
   $errortext = $ccErrors [$errornumber];
    $error_elements[$cc_validate_id] = $ccErrors [$errornumber];
    $failcheck = 4;
    }; 
   
    }
    }
    //====================END CC Validation=======================

   This is probably not perfect nor is it most likely the most efficient method, but it is tested and does work. I hope it can be of some use for others out there!

   Posted 12 years ago #
2. 

   yuniar

   Thank you for sharing this!

   ---

   MachForm Founder

   Posted 12 years ago #

3. aolmos
   Member

   How can I include this code in machform 2? We have customized our machform and we can't switch to machform 3

   Posted 12 years ago #

4. tmparisi
   Member

   Hi aolmos, unfortunately I cannot help you with this. I have never used v2. Best of luck!

   Posted 11 years ago #

5. aolmos
   Member

   What about version 4?

   Posted 10 years ago #

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