保守性を悪くするレールズの書き方アンチパターン

保守性についての基本的な考え方と具体例

Transcript

1. ษڧձࢿྉ 2016-6-7 อकੑΛѱ͘͢ΔϨʔϧ ζͷॻ͖ํΞϯνύλʔϯ UXJUUFS
   !@TIJNBEB
   ౡాܚथ
2. ࠷ॳʹʮอकੑʯͷ࿩Λ
   ͪΐͬͱ͠·͢
3. Ξϯέʔτ ❖ ଞͷਓ͕ॻ͍ͨίʔυΛಡΜͰվ଄ͨ͜͠ͱ͕͋Γ·͢ ͔ʁ
4. อकͱ͸ ❖ Ͱ͖͕͋ͬͨϓϩάϥϜͷόάमਖ਼ɺػೳ௥ՃͳͲΛߦ ͏͜ͱ
   ❖ ձࣾͷ࢓ࣄͰ͸ɺ࠷ॳʹ࡞ͬͨਓͱ͸ผͷਓ͕୲౰͢ Δ͜ͱ͕ଟ͍
5. อकੑͱ͸ ❖ όάमਖ਼΍ػೳ௥ՃͳͲͷ΍Γ΍͢͞ͷ౓߹͍
   ❖ อकੑ͕ߴ͍
   
   (00%
   ❖ อकੑ͕௿͍
   
   #"%
6. อकੑ͸ॏཁ ❖ อक͠ʹ͍͘ιʔείʔυΛॻ͘ͱɺ͋ͱͰอक͢Δਓ ʹ໎࿭Λ͔͚Δ
   ❖ ޻਺͕༨ܭʹ͔͔ΔͷͰձࣾͷऩӹʹ΋ϚΠφε
   ❖ ʮٕज़తෛ࠴ʯ
   ❖ ࣗ෼Ͱॻ͍ͨίʔυΛࣗ෼Ͱอक͢Δͱ͖͸ࣗ෼ࣗ਎ ʹฦͬͯ͘Δ
7. อकੑΛؾʹ͠ͳͯ͘Α͍έʔε ❖ ࣗ෼Ͱॻ͍ͯࣗ෼Ͱӡ༻͢Δझຯͷίʔυ
   ❖ Ұճॻ͍ͯಈ͔ͨ͠Β΋͏ೋ౓ͱ࢖Θͳ͍࢖͍ࣺͯͷε ΫϦϓτ
   ˞ଞࣾʹೲ඼͢ΔडୗγεςϜ͸ؾʹ͍ͯͩ͘͠͞
8. ϓϩάϥϜͷಈ࡞Λม͍͑ͨͱ͖ʹ΍Δ͜ͱ  ม͍͑ͨݩͷಈ࡞͕Ͳ͜ͰߦΘΕ͍ͯΔ͔ௐ΂Δ
    Ͳ͏͍ͬͨ͡Βม͑ΒΕΔ͔ߟ͑Δ
    ҙਤ௨ΓมΘΔ͔ௐ΂Δɾࢼͯ͠ΈΔ
    ͍͡Δ͜ͱͰผͷͱ͜ΖʹӨڹ͕ͳ͍͔ௐ΂Δɾࢼ͠ ͯΈΔ
9. Ͳ͏͍͏ιʔείʔυ͕อकੑ͕ߴ͍͔  ม͍͑ͨݩͷಈ࡞͕Ͳ͜ͰߦΘΕ͍ͯΔ͔ௐ΂Δ
   ❖ ม͍͑ͨಈ࡞͕ߦΘΕ͍ͯΔ৔ॴΛௐ΂΍͍͢
    Ͳ͏͍ͬͨ͡Βม͑ΒΕΔ͔ߟ͑Δ
   ❖ ಈ࡞ͷม͔͑ͨΛਪଌ͠΍͍͢
    ҙਤ௨ΓมΘΔ͔ௐ΂Δɾࢼͯ͠ΈΔ
   ❖ ಈ࡞ͷมԽΛࢼ͠΍͍͢
    ͍͡Δ͜ͱͰผͷͱ͜ΖʹӨڹ͕ͳ͍͔ௐ΂Δɾࢼͯ͠ΈΔ
   ❖ ͋Δ෦෼ͷมߋ͕ผͷͱ͜ΖʹӨڹͮ͠Β͍
10. ίϯτϩʔϥͷΞϯνύλʔϯ ❖ CFGPSF@BDUJPOͷཚ༻
    ❖ Πϯελϯεม਺ʢ!ม਺ʣߦํෆ໌໰୊
    ❖ ϓϥΠϕʔτϝιουଟ͗͢໰୊
    ❖ ໊લ͕࣮ଶʹ߹ͬͯͳ͍໰୊
11. αϯϓϧίʔυ
    ʢۃ୺ͳྫʣ ※極端な例ですがどれも実体験に基づきます
12. class BadController < ActionController::Base before_action :get_service_objects, only: [:index, :show, :edit] def index end def show end def edit end private def get_service_objects @service = Service.find(params[:service_id]) @user = User.find(params[:user_id]) @items = Item.where(service_id: @service.id, user_id: @user.id) end end
13. class BadController < ActionController::Base before_action :get_service_objects, only: [:index, :show, :edit] def index end def show end def edit end private def get_service_objects @service = Service.find(params[:service_id]) @user = User.find(params[:user_id]) @items = Item.where(service_id: @service.id, user_id: @user.id) end end HFUͰ͸ͳ͘TFU !ม਺Λ֎ͰՃ޻ ͦΕ͸ΞΫγϣϯͷલॲཧ͔ʁ ࣮ࡍͷॲཧ͸Ͳ͜ʹʁ
14. ʬσΟεΧογϣϯʭ
    Ͳ͏͢Ε͹ྑ͘ͳΔ͔ʁ
15. class GoodController < ActionController::Base def index @service = get_service(params[:service_id]) @user = get_user(params[:user_id]) @items = get_items(params[:service_id], params[:user_id]) end def show @service = get_service(params[:service_id]) @user = get_user(params[:user_id]) @items = get_items(params[:service_id], params[:user_id]) end def edit @service = get_service(params[:service_id]) @user = get_user(params[:user_id]) @items = get_items(params[:service_id], params[:user_id]) end private def get_service(service_id) Service.find(service_id) end def get_use(user_id) User.find(user_id) end def get_items(service_id, user_id) Item.where(service_id, user_id) end end
16. class GoodController < ActionController::Base def index @service = get_service(params[:service_id]) @user = get_user(params[:user_id]) @items = get_items(params[:service_id], params[:user_id]) end def show @service = get_service(params[:service_id]) @user = get_user(params[:user_id]) @items = get_items(params[:service_id], params[:user_id]) end def edit @service = get_service(params[:service_id]) @user = get_user(params[:user_id]) @items = get_items(params[:service_id], params[:user_id]) end private def get_service(service_id) Service.find(service_id) end def get_use(user_id) User.find(user_id) end def get_items(service_id, user_id) Item.where(service_id, user_id) end end ֎෦͔Βͷೖྗ͸͢΂ͯ
    ΞΫγϣϯ಺Ͱड͚औΔ Ϗϡʔʹ౉͢஋͸͢΂ͯ
    ΞΫγϣϯ಺Ͱઃఆ͢Δ
17. ·ͱΊ ❖ ࢓༷Λຬ͚ͨͩ͢Ͱͳ͘ɺอकੑͷߴ͍ίʔυΛॻ͜͏
    ❖ อकੑΛߴΊΔͨΊͷٕज़Λֶͼɺ਎ʹ͚ͭΑ͏
    ❖ ͋ͱ͔ΒಡΉਓͷཱ৔ʹཱͬͯߟ͑Δ͜ͱ͕େ੾