1. <?php
  3. /**
  4. * String Constraint Checker for Legacy Project
  5. *
  6. * Performs basic sanity checks on strings.
  7. *
  8. * @param string $string The string to validate.
  9. * @param array $constraints An array of constraints. Each constraint is an associative array with keys:
  10. * - 'min_length' (int, optional): Minimum length of the string.
  11. * - 'max_length' (int, optional): Maximum length of the string.
  12. * - 'allowed_chars' (string, optional): Only allow these characters.
  13. * - 'required' (bool, optional): String must not be empty.
  14. * @return array An array of validation errors. Empty array if no errors.
  15. */
  16. function validateString(string $string, array $constraints): array
  17. {
  18. $errors = [];
  20. if (isset($constraints['min_length']) && strlen($string) < $constraints['min_length']) {
  21. $errors[] = "Minimum length is {$constraints['min_length']} characters.";
  22. }
  24. if (isset($constraints['max_length']) && strlen($string) > $constraints['max_length']) {
  25. $errors[] = "Maximum length is {$constraints['max_length']} characters.";
  26. }
  28. if (isset($constraints['allowed_chars'])) {
  29. if (preg_match('/^' . preg_quote($constraints['allowed_chars'], '/') . '$/', $string)) {
  30. $errors[] = "String contains invalid characters.";
  31. }
  32. }
  34. if (isset($constraints['required']) && empty($string)) {
  35. $errors[] = "String is required.";
  36. }
  38. return $errors;
  39. }
  41. // Example Usage (can be removed for production)
  42. /*
  43. $string = "ValidString";
  44. $constraints = [
  45. 'min_length' => 5,
  46. 'max_length' => 10,
  47. 'allowed_chars' => 'abcdefg123',
  48. 'required' => true,
  49. ];
  51. $errors = validateString($string, $constraints);
  53. if (!empty($errors)) {
  54. echo "Validation Errors:\n";
  55. foreach ($errors as $error) {
  56. echo "- " . $error . "\n";
  57. }
  58. } else {
  59. echo "String is valid.\n";
  60. }
  61. */
  63. ?>

Add your comment