Relation n->m : uninitialized constant User::UserHasPin

Bonjour,

Je suis confronté à un problème dans le cadre de mon application rails.

Voici mon model concernant la base de donnée (sous SQLite) :
http://img15.hostingpics.net/pics/878611model1opt.png

J'ai en effet l'exception suivante : (je voulais juste faire un test pour voir si j'arrive à compter le nombre pins pour un utilisateur)

Code:

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NameError in Users#show   Showing /app/views/shared/_users_pins.html.erb where line #3 raised:   uninitialized constant User::UserHasPin Extracted source (around line #3):   1: <% @user ||= current_user %> 2: <div class="stats"> 3: <%= @user.pins_id.count %> 4: </div>

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Voici les 3 models qui sont associés :

Code:

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class UserHasPins < ActiveRecord::Base attr_accessible :users_id, :pins_id belongs_to :users_id belongs_to :pins_id validates :users_id, presence: true validates :pins_id, presence: true end

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Code:

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class User < ActiveRecord::Base has_many :pins_id, :through => :user_has_pin has_many :user_has_pin end

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Code:

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class Pins < ActiveRecord::Base attr_accessible :content, :title has_many :users_id, :through => :user_has_pin has_many :user_has_pin

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Si quelqu'un voit pourquoi j'ai cette exception ? =)

Merci par avance de vos réponses :)

Je suis pas fan du nomage de tes variables et par expérience (pour avoir galeré aussi) Ruby va utiliser les transformations singulier/pluriel pour retrouver le nom de la classe liée au has_many
d'ailleurs tu peux le forcer en utilisant la variable :class

Revenons à ton erreur: ton modele et tes relations ne sont pas correcte, commence par regler ça !

je ferai tellement de changement que je ne sais pas par ou commencer, les noms des classes au singulier, les belong_to au singulier et les has_many au pluriel
(et oui, c'est un maniac de la grammaire qui à créé ce langage)

Code:

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class UserHasPin < ActiveRecord::Base   belongs_to :user belongs_to :pin

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Code:

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class Pin < ActiveRecord::Base attr_accessible :content, :title     has_many :users, :through => :user_has_pins, :source => :user has_many :user_has_pins

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ajout de la :source pour aider ruby à determiner le sens de la relation

Code:

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class User < ActiveRecord::Base     has_many :pins, :through => :user_has_pins, :source => :pin has_many :user_has_pins end

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j'ai pas testé mais j'ai un modele de base qui ressemble un peu ....

Tu peux facilement tester en utilisant la console rails, en creant un objet et en appellant la methode, cela doit te renvoyer [] puisque le lien n'existe pas, mais cela ne doit pas te planter
(attention à chaque modification du modele, il faut relancer la console pour prendre en compte les modifications

bon courage !

j'ai trouvé le temps de tester:

Code:

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$ rails generate model user $ rails generate model pin $ rails generate model userHasPin

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je changerais aussi le nom de tes foreign keys :mrgreen:

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class CreateUserHasPins < ActiveRecord::Migration def change create_table :user_has_pins do |t| t.integer :user_id t.integer :pin_id   t.timestamps end end end

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mais ça marche beaucoup mieux

Code:

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$ rails c Loading development environment (Rails 3.2.2) irb(main):001:0> p1 = Pin.create(:title => "Pokemon") ←[1m←[36m (0.0ms)←[0m ←[1mbegin transaction←[0m ←[1m←[35mSQL (37.0ms)←[0m INSERT INTO "pins" ("created_at", "title", "updated_at") VALUES (?, ?, ?) [["created_at", Fri, 27 Jul 2012 07:56:53 UTC +00:00], ["title", "Pokemon"], ["updated_at", Fri, 27 Jul 2012 0 7:56:53 UTC +00:00]] ←[1m←[36m (6.0ms)←[0m ←[1mcommit transaction←[0m => #<Pin id: 1, title: "Pokemon", created_at: "2012-07-27 07:56:53", updated_at: "2012-07-27 07:56:53"> irb(main):002:0> p2 = Pin.create(:title => "Yugiho") ←[1m←[35m (0.0ms)←[0m begin transaction ←[1m←[36mSQL (2.0ms)←[0m ←[1mINSERT INTO "pins" ("created_at", "title", "updated_at") VALUES (?, ?, ?)←[0m [["created_at", Fri, 27 Jul 2012 07:57:06 UTC +00:00], ["title", "Yugiho"], ["updated_at", Fri, 27 Jul 2012 07:57:06 UTC +00:00]] ←[1m←[35m (8.0ms)←[0m commit transaction => #<Pin id: 2, title: "Yugiho", created_at: "2012-07-27 07:57:06", updated_at: "2012-07-27 07:57:06"> irb(main):003:0> u = User.create() ←[1m←[36m (0.0ms)←[0m ←[1mbegin transaction←[0m ←[1m←[35mSQL (2.0ms)←[0m INSERT INTO "users" ("created_at", "updated_at") VALUES (?, ?) [["created_at", Fri, 27 Jul 2012 07:57:18 UTC +00:00], ["updated_at", Fri, 27 Jul 2012 07:57:18 UTC +00:00]] ←[1m←[36m (5.0ms)←[0m ←[1mcommit transaction←[0m => #<User id: 1, created_at: "2012-07-27 07:57:18", updated_at: "2012-07-27 07:57:18"> irb(main):004:0> u.user_has_pins.create(:pin_id => 1) ←[1m←[35m (0.0ms)←[0m begin transaction ←[1m←[36mSQL (1.0ms)←[0m ←[1mINSERT INTO "user_has_pins" ("created_at", "pin_id", "updated_at", "user_id") VALUES (?, ?, ?, ?)←[0m [["created_at", Fri, 27 Jul 2012 07:57:58 UTC +00:00], ["pin_id", 1], ["updated_at", Fri, 27 Jul 2012 07:57:58 UTC +00:00], ["user_id", 1]] ←[1m←[35m (4.0ms)←[0m commit transaction => #<UserHasPin id: 1, user_id: 1, pin_id: 1, created_at: "2012-07-27 07:57:58", updated_at: "2012-07-27 07:57:58"> irb(main):005:0> u.pins ←[1m←[36mPin Load (0.0ms)←[0m ←[1mSELECT "pins".* FROM "pins" INNER JOIN "user_has_pins" ON "pins"."id" = "user_has_pins"."pin_id" WHERE "user_has_pins"."user_id" = 1←[0m => [#<Pin id: 1, title: "Pokemon", created_at: "2012-07-27 07:56:53", updated_at: "2012-07-27 07:56:53">] irb(main):006:0> p1.users ←[1m←[35mUser Load (1.0ms)←[0m SELECT "users".* FROM "users" INNER JOIN "user_has_pins" ON "users"."id" = "user_has_pins"."user_id" WHERE "user_has_pins"."pin_id" = 1 => [#<User id: 1, created_at: "2012-07-27 07:57:18", updated_at: "2012-07-27 07:57:18">] irb(main):007:0> p2.users ←[1m←[36mUser Load (1.0ms)←[0m ←[1mSELECT "users".* FROM "users" INNER JOIN "user_has_pins" ON "users"."id" = "user_has_pins"."user_id" WHERE "user_has_pins"."pin_id" = 2←[0m => []

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