diogo
/
symfony
Archived
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[Validator] Simplified and explained the LuhnValidator

This commit is contained in:
Bernhard Schussek 2014-04-10 19:30:28 +02:00
parent bff09f210b
commit f3295522ef
1 changed files with 32 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
src/Symfony/Component/Validator/Constraints/LuhnValidator.php
View File

@ -39,28 +39,48 @@ class LuhnValidator extends ConstraintValidator
return;
}
/**
* need to work with strings only because long numbers are treated as floats and don't work with strlen
*/
if (!is_string($value)) {
// Work with strings only, because long numbers are represented as floats
// internally and don't work with strlen()
if (!is_string($value) && !(is_object($value) && method_exists($value, '__toString'))) {
throw new UnexpectedTypeException($value, 'string');
}
if (!is_numeric($value)) {
$this->context->addViolation($constraint->message);
$value = (string) $value;
if (!ctype_digit($value)) {
$this->context->addViolation($constraint->message, array(
'{{ value }}' => $value,
));
return;
}
$checkSum = 0;
$length = strlen($value);
$oddLength = $length % 2;
for ($sum = 0, $i = $length - 1; $i >= 0; $i--) {
$digit = (int) $value[$i];
$sum += (($i % 2) === $oddLength) ? array_sum(str_split($digit * 2)) : $digit;
// Starting with the last digit and walking left, add every second
// digit to the check sum
// e.g. 7 9 9 2 7 3 9 8 7 1 3
// ^ ^ ^ ^ ^ ^
// = 7 + 9 + 7 + 9 + 7 + 3
for ($i = $length - 1; $i >= 0; $i -= 2) {
$checkSum += $value{$i};
}
if ($sum === 0 || ($sum % 10) !== 0) {
$this->context->addViolation($constraint->message);
// Starting with the second last digit and walking left, double every
// second digit and add it to the check sum
// For doubles greater than 9, sum the individual digits
// e.g. 7 9 9 2 7 3 9 8 7 1 3
// ^ ^ ^ ^ ^
// = 1+8 + 4 + 6 + 1+6 + 2
for ($i = $length - 2; $i >= 0; $i -= 2) {
$checkSum += array_sum(str_split($value{$i} * 2));
}
if (0 === $checkSum || 0 !== $checkSum % 10) {
$this->context->addViolation($constraint->message, array(
'{{ value }}' => $value,
));
}
}
}