制約でコードに秩序を

2016/05/21 PHP カンファレンス福岡 2016

Transcript

1. ɹ!shin1x1
   2016/05/21 1)1ΧϯϑΝϨϯε෱Ԭ
   ੍໿ͰίʔυʹடংΛ
   

   View Slide

2. ੍໿ͱ͸
   

   View Slide

3. ੍ݶ΍৚݅Λ͚ͭͯ
   ࣗ༝ʹ׆ಈͤ͞ͳ͍͜ͱ
   https://kotobank.jp/word/%E5%88%B6%E7%B4%84-546519
   

   View Slide

4. ੍ݶ΍৚݅Λ͚ͭͯ
   ࣗ༝ʹ׆ಈͤ͞ͳ͍͜ͱ
   https://kotobank.jp/word/%E5%88%B6%E7%B4%84-546519
   

   View Slide

5. ࠓ೔ͷ୊ࡐ
   

   View Slide

6. &$αΠτ
   γϣοϐϯάΧʔτ
   

   View Slide

7. Χʔτʹ௥Ճ
   

   View Slide

8. ΧʔτΛදࣔ
   

   View Slide

9. 
   Χʔτʹ঎඼Λ௥Ճ
   

   View Slide

10. D
    .BTBTIJ4IJOCBSB!TIJOY
    Χʔτʹ঎඼Λ௥Ճ
    wΧʔτ$BSUΫϥε
    w঎඼*UFNΫϥε
    w$BSUJUFNTʹ঎඼Λ௥Ճ
    

    View Slide

11. *UFN
    class Item

    {

    public $code;

    public $price;

    

    public function __construct(string $code, int $price)

    {

    $this->code = $code;

    $this->price = $price;

    }

    }
    

    View Slide

12. $BSU
    class Cart

    {

    public $items;

    

    public function __construct()

    {

    $this->items = [];

    }

    

    public function calculateTotalPrice(): int

    {

    $totalPrice = 0;

    

    foreach ($this->items as $item) {

    $totalPrice = $totalPrice + $item->price;

    }

    

    return $totalPrice;

    }

    }
    

    View Slide

13. D
    .BTBTIJ4IJOCBSB!TIJOY
    ঎඼௥ՃΛ*UFNΫϥεʹݶఆ
    w$BSUJUFNTΛQSJWBUFͰӅ͢
    wBEE*UFNϝιουΛ௥Ճ
    wλΠϓώϯςΟϯάͰ*UFNΫϥεʹݶఆ
    

    View Slide

14. $BSU
    class Cart

    {

    private $items;

    

    public function __construct()

    {

    $this->items = [];

    }

    

    public function addItem(Item $item)

    {

    $this->items[] = $item;

    }

    (snip)
    }
    QSJWBUF
    λΠϓώϯςΟϯά
    

    View Slide

15. D
    .BTBTIJ4IJOCBSB!TIJOY
    ΞΫηεम০ࢠλΠϓώϯςΟϯά
    wΫϥεࣗ਎͕ϓϩύςΟΛίϯτϩʔϧ
    wΫϥε֎ʹίϯτϩʔϧΛ౉͞ͳ͍
    wૢ࡞ํ๏Λݶఆ͍ͯ͠Δ͔Βͦ͜

    ίϯτϩʔϧͰ͖Δ

    ʢλΠϓώϯςΟϯάͳͲʣ
    

    View Slide

16. 
    Χʔτͷ঎඼఺਺͸
    ఺·Ͱ
    

    View Slide

17. D
    .BTBTIJ4IJOCBSB!TIJOY
    Χʔτͷ঎඼఺਺͸఺Ҏ಺
    w఺Ҏ্ͷ঎඼Λ֨ೲ͠Α͏ͱͨ͠Βྫ֎ൃੜ
    w঎඼௥ՃͷࡍʹνΣοΫΛߦ͏
    

    View Slide

18. D
    .BTBTIJ4IJOCBSB!TIJOY
    BEE*UFNϝιουͰ੍໿
    wBEE*UFNϝιουͰ঎඼఺਺ΛνΣοΫ
    w͜ͷϝιουͰ͔͠$BSUJUFNTΛ

    มߋͰ͖ͳ͍ͷͰ༗ޮ
    wϓϩύςΟͷίϯτϩʔϧΛΫϥεࣗ਎͕ߦ͏

    QVCMJDͩͱ֎෦ʹίϯτϩʔϧ͞ΕΔ
    

    View Slide

19. $BSU
    class Cart

    {
    (snip)

    public function addItem(Item $item)

    {

    if (count($this->items) >= 3) {

    throw new PreconditionException();

    }

    

    $this->items[] = $item;

    }
    (snip)

    }
    

    View Slide

20. 
    ঎඼খܭʹ
    ফඅ੫ΛՃࢉ
    

    View Slide

21. D
    .BTBTIJ4IJOCBSB!TIJOY
    ੫ࠐՁ֨ࢉग़
    wΧʔτͷ঎඼ͦΕͧΕʹফඅ੫ΛՃࢉ
    w੫ࠐΈՁ֨ͷ߹ܭΛখܭՁ֨ͱ͢Δ
    

    View Slide

22. $BSU
    $cart = new Cart();

    

    $item1 = new Item('code1', 100);

    $cart->addItem($item1);

    

    $item2 = new Item('code2', 200);

    $cart->addItem($item2);

    

    $this->assertEquals(324, $cart->calculateTotalPrice());

    $this->assertEquals(324, $cart->calculateTotalPrice());
    ʹͳΔʁʁʁ
    

    View Slide

23. $BSU
    class Cart

    {
    (snip)

    public function calculateTotalPrice(): int

    {

    $totalPrice = 0;

    

    foreach ($this->items as $item) {

    $item->price = (int)($item->price * 1.08);

    $totalPrice = $totalPrice + $item->price;

    }

    

    return $totalPrice;

    }
    (snip)

    }
    *UFNQSJDF͕
    มߋ͞ΕΔ
    ճݺͿͱ
    ͞ΒʹഒʹͳΔ
    

    View Slide

24. D
    .BTBTIJ4IJOCBSB!TIJOY
    *UFNΫϥεΛෆมʹ͢Δ
    w׬શίϯετϥΫλ

    ίϯετϥΫλͰશͯͷ஋Λ༩͑Δ
    wෆมʢΠϛϡʔλϒϧʣΫϥε

    QSJDF
    ͸ৗʹಉ͡஋Λฦ͢
    wඞཁͳHFUUFSͷΈ࣮૷
    

    View Slide

25. *UFN
    class Item

    {

    private $code;

    private $price;

    

    public function __construct(string $code, int $price)

    {

    $this->code = $code;

    $this->price = $price;

    }

    

    public function price(): int

    {

    return $this->price;

    }

    }
    QSJWBUF
    

    View Slide

26. $BSU
    class Cart

    {
    (snip)

    public function calculateTotalPrice(): int

    {

    $totalPrice = 0;

    

    foreach ($this->items as $item) {

    $price = (int)($item->price() * 1.08);

    $totalPrice = $totalPrice + $price;

    }

    

    return $totalPrice;

    }
    (snip)

    }
    *UFNQSJDF͸
    มߋͰ͖ͳ͍
    

    View Slide

27. 
    Ձ֨΁ͷૢ࡞Λݶఆ
    

    View Slide

28. D
    .BTBTIJ4IJOCBSB!TIJOY
    Ձ֨ͷԋࢉΛ੍ݶ
    wJOUͩͱҙຯ͕޿͗͢ΔʢՄೳͳԋࢉ΋ଟ͍ʣ
    w଍͠ࢉͱ੫ࠐՁ֨ܭࢉʢֻ͚ࢉͰ͸ͳ͍ʣͷΈ
    wՁ֨Λ1SJDFΫϥεͰදݱ
    

    View Slide

29. 1SJDF
    class Price

    {

    const TAX_RATE = 1.08;

    private $price;

    

    public function __construct(int $price)

    {

    $this->price = $price;

    }

    

    public function add(self $price): self

    {

    return new self($this->price + $price->price);

    }

    

    public function withTax(): self

    {

    return new self((int)($this->price * static::TAX_RATE));

    }

    

    public function toInt(): int

    {

    return $this->price;

    }

    }
    

    View Slide

30. *UFN
    class Item

    {

    private $code;

    private $price;

    

    public function __construct(string $code, int $price)

    {

    $this->code = $code;

    $this->price = new Price($price);

    }

    

    public function price(): Price

    {

    return $this->price;

    }

    }
    

    View Slide

31. $BSU
    class Cart

    {
    (snip)

    public function calculateTotalPrice(): Price

    {

    $totalPrice = new Price(0);

    

    foreach ($this->items as $item) {

    $price = $item->price()->withTax();

    $totalPrice = $totalPrice->add($price);

    }

    

    return $totalPrice;

    }
    (snip)

    }
    Ձ֨͸1SJDFͰදݱ
    ੫ࠐՁ֨ࢉग़
    Ձ֨ͷ଍͠ࢉ
    

    View Slide

32. D
    .BTBTIJ4IJOCBSB!TIJOY
    7BMVF0CKFDU
    w஋ΛΫϥεͰදݱ
    wෆมΫϥε

    ԋࢉ݁Ռ͸৽͍͠ΠϯελϯεͰฦ͢
    wඞཁͳԋࢉͷΈΛ࣮૷
    w಺෦ͷ஋ΛӅณ
    

    View Slide

33. 
    ঎඼ɺΧʔτ৘ใΛ
    +40/Ͱग़ྗ
    

    View Slide

34. D
    .BTBTIJ4IJOCBSB!TIJOY
    ঎඼ɺΧʔτ৘ใΛ+40/Ͱग़ྗ
    w+BWB4DSJQUΫϥΠΞϯτ΍

    εϚʔτϑΥϯΞϓϦ࿈ܞ
    w*UFNUP"SSBZ
    Ͱ഑ྻͱͯ͠ग़ྗ
    wKTPO@FODPEF
    Ͱ+40/ʹ͢Δ
    

    View Slide

35. "QJ$POUSPMMFS
    class ApiController

    {

    public function item()

    {

    $item = new Item('code1', 100);

    $this->json($item);

    }

    

    private function json(Item $entity)

    {

    header('Content-Type: application/json');

    echo json_encode($entity->toArray());

    }

    }
    

    View Slide

36. class ApiController

    {

    public function item()

    {

    $item = new Item('code1', 100);

    $this->json($item);

    }

    public function cart()

    {

    $cart = new Cart();

    $cart->addItem(new Item('code1', 100));

    $cart->addItem(new Item('code2', 200));

    

    $this->json($cart);

    }
    private function json(Item $entity)

    {

    header('Content-Type: application/json');

    echo json_encode($entity->toArray());

    }

    }
    DBSU͸

    *UFNΫϥεͰ͸ͳ͍
    

    View Slide

37. D
    .BTBTIJ4IJOCBSB!TIJOY
    "SSBZBCMFΠϯλʔϑΣΠε
    w"QJ$POUSPMMFSKTPO
    ͕

    ඞཁͳґଘΛΠϯλʔϑΣΠεͰ໌ࣔ
    wΠϯλʔϑΣΠε࣮͑͞૷͍ͯ͠Ε͹

    ͲΜͳΫϥεͰ΋ྑ͍
    w࢓༷ͱ࣮૷ͷ෼཭
    

    View Slide

38. "SSBZBCMF
    interface Arrayable

    {

    public function toArray(): array;

    }
    

    View Slide

39. *UFN
    class Item implements Arrayable

    {

    (snip)
    public function toArray(): array

    {

    return [

    'code' => $this->code,

    'price' => $this->price->toInt(),

    ];

    }

    }
    

    View Slide

40. $BSU
    class Cart implements Arrayable

    {

    (snip)
    public function toArray(): array

    {

    return array_map(function (Item $item) {

    return $item->toArray();

    }, $this->items);

    }

    }
    

    View Slide

41. class ApiController

    {

    public function item()

    {

    $item = new Item('code1', 100);

    $this->json($item);

    }

    public function cart()

    {

    $cart = new Cart();

    $cart->addItem(new Item('code1', 100));

    $cart->addItem(new Item('code2', 200));

    

    $this->json($cart);

    }
    private function json(Arryable $entity)

    {

    header('Content-Type: application/json');

    echo json_encode($entity->toArray());

    }

    }
    "SSBZBCMF
    

    View Slide

42. D
    .BTBTIJ4IJOCBSB!TIJOY
    ˞ิ଍
    1)1ʹ͸ɺ+TPO4FSJBMJ[BCMFͱ͍͏

    ΠϯλʔϑΣΠε͕͋Γ·͢ɻ

    ΦϒδΣΫτΛ+40/Խ͢Δࡍ͸

    ࢀߟʹ͍ͯͩ͘͠͞ɻ
    http://php.net/manual/ja/class.jsonserializable.php
    

    View Slide

43. ੍໿ͱ͸
    

    View Slide

44. ࣗ༝Λୣ͏
    ໘౗ͳ΋ͷͰ͸ͳ͘
    

    View Slide

45. டংΛकΓ
    ҙਤΛ໌֬ʹ͢Δ΋ͷ
    ੍໿
    ΘΜͺ͘ͳίʔυ
    https://flic.kr/p/4e5ggf
    ίʔυͷடংΛ
    कΔ΋ͷ
    

    View Slide

46. ੍໿Ͱடং͋Δ։ൃΛʂ
    

    View Slide

47. D
    .BTBTIJ4IJOCBSB!TIJOY
    !TIJOY
    !TIJOY
    D
    .BTBTIJ4IJOCBSB!TIJOY
    

    View Slide

48. D
    .BTBTIJ4IJOCBSB!TIJOY
    QSPUFDUFEPSQSJWBUF
    w·ͣ͸ɺQSJWBUFඞཁͳΒQSPUFDUFE
    w͍͔ͭݺ͹ΕΔ͔΋͠Εͳ͍͔ΒQSPUFDUFE

    :"(/*ʢ:PVBJOUHPOOBOFFEJUʣ
    wଞਓ͕࡞ͬͨγεςϜΛϝϯςφϯε͢Δͱ

    QSJWBUFສࡀʹͳΔ
    wUSBJU͕͋ΔͷͰɺػೳͷͨΊʹܧঝ͢Δඞཁ͕ແ͍
    

    View Slide