Complex classes like Card often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Card, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 13 | abstract class Card |
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| 14 | { |
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| 15 | /** |
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| 16 | * Regular expression for card number recognition. |
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| 17 | * |
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| 18 | * @var string |
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| 19 | */ |
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| 20 | public static $pattern; |
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| 21 | |||
| 22 | /** |
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| 23 | * Credit card type: "debit", "credit". |
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| 24 | * |
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| 25 | * @var string |
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| 26 | */ |
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| 27 | protected $type; |
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| 28 | |||
| 29 | /** |
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| 30 | * Credit card name. |
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| 31 | * |
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| 32 | * @var string |
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| 33 | */ |
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| 34 | protected $name; |
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| 35 | |||
| 36 | /** |
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| 37 | * Card number length's. |
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| 38 | * |
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| 39 | * @var array |
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| 40 | */ |
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| 41 | protected $number_length; |
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| 42 | |||
| 43 | /** |
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| 44 | * CVC code length's. |
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| 45 | * |
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| 46 | * @var array |
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| 47 | */ |
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| 48 | protected $cvc_length; |
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| 49 | |||
| 50 | /** |
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| 51 | * Test cvc code checksum against Luhn algorithm. |
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| 52 | * |
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| 53 | * @var bool |
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| 54 | */ |
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| 55 | protected $checksum_test; |
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| 56 | |||
| 57 | /** |
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| 58 | * @var string |
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| 59 | */ |
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| 60 | private $card_number; |
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| 61 | |||
| 62 | /** |
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| 63 | * Card constructor. |
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| 64 | * |
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| 65 | * @param string $card_number |
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| 66 | * |
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| 67 | * @throws \LVR\CreditCard\Exceptions\CreditCardException |
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| 68 | */ |
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| 69 | 95 | public function __construct(string $card_number = '') |
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| 77 | |||
| 78 | /** |
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| 79 | * @param string $card_number |
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| 80 | * |
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| 81 | * @return $this |
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| 82 | * @throws \LVR\CreditCard\Exceptions\CreditCardPatternException |
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| 83 | */ |
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| 84 | 67 | public function setCardNumber(string $card_number) |
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| 98 | |||
| 99 | /** |
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| 100 | * @return bool |
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| 101 | * @throws \LVR\CreditCard\Exceptions\CreditCardChecksumException |
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| 102 | * @throws \LVR\CreditCard\Exceptions\CreditCardException |
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| 103 | * @throws \LVR\CreditCard\Exceptions\CreditCardLengthException |
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| 104 | */ |
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| 105 | 55 | public function isValidCardNumber() |
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| 125 | |||
| 126 | /** |
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| 127 | * @return string |
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| 128 | */ |
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| 129 | 11 | public function type() |
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| 133 | |||
| 134 | /** |
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| 135 | * @param $cvc |
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| 136 | * |
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| 137 | * @return bool |
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| 138 | */ |
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| 139 | 1 | public function isValidCvc($cvc) |
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| 144 | |||
| 145 | /** |
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| 146 | * Check CVS length against possible lengths. |
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| 147 | * |
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| 148 | * @param string|int $cvc |
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| 149 | * |
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| 150 | * @param array $available_lengths |
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| 151 | * |
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| 152 | * @return bool |
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| 153 | */ |
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| 154 | 2 | public static function isValidCvcLength($cvc, array $available_lengths = [3, 4]) |
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| 160 | |||
| 161 | /** |
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| 162 | * @param string $year |
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| 163 | * @param string $month |
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| 164 | * |
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| 165 | * @return bool |
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| 166 | */ |
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| 167 | 4 | public static function isValidExpirationDate(string $year, string $month) |
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| 190 | |||
| 191 | /** |
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| 192 | * @throws \LVR\CreditCard\Exceptions\CreditCardException |
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| 193 | */ |
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| 194 | 95 | protected function checkImplementation() |
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| 228 | |||
| 229 | /** |
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| 230 | * @return bool |
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| 231 | */ |
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| 232 | 67 | protected function validPattern() |
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| 236 | |||
| 237 | /** |
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| 238 | * @return bool |
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| 239 | */ |
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| 240 | 44 | protected function validLength() |
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| 244 | |||
| 245 | /** |
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| 246 | * @return bool |
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| 247 | */ |
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| 248 | 33 | protected function validChecksum() |
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| 252 | |||
| 253 | /** |
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| 254 | * @return bool |
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| 255 | */ |
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| 256 | 31 | protected function checksumTest() |
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| 275 | } |
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| 276 |
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using
empty(..)or! empty(...)instead.