【发布时间】：2014-06-27 14:12:34
【问题描述】：
问题
我一直在搞乱 ruby、grape、grape-entity 和 activerecord。一切都很顺利，但是当使用 using 关键字作为 expose 项目时，我看不到从葡萄实体获得所需的结果。
我的目标是基本上解决我所有的activerecord 关联，然后返回生成的 JSON。这样我就有了一个完整的对象来展示我的配置 API 方法。
如果您需要更多信息，请询问我会很乐意提供任何东西。
注意：我使用 rackup 作为我的服务器，我根本没有使用 rails。
类
console_game.rb
class ConsoleGame < ActiveRecord::Base
self.table_name = 'console_game'
self.primary_key = :id
has_many :configurations, :class_name => 'Configuration'
class Entity < Grape::Entity
expose :id
expose :value, :as => :console_game
end
end
cloud_user.rb
class CloudUser < ActiveRecord::Base
self.primary_key = :username
has_many :configurations, :class_name => 'Configuration'
has_many :favorites, :class_name => 'Favorite', :foreign_key => :username
class Entity < Grape::Entity
expose :username, :email, :first_name, :last_name
end
end
device.rb
class Device < ActiveRecord::Base
self.table_name = 'device'
self.primary_key = :id
has_many :configurations, :class_name => 'Configuration'
class Entity < Grape::Entity
expose :id
expose :name, :as => :device
end
end
console_system.rb
class ConsoleSystem < ActiveRecord::Base
self.table_name = 'console_system'
self.primary_key = :id
has_many :configurations, :class_name => 'Configuration'
class Entity < Grape::Entity
expose :id
expose :value, :as => :console_system
end
end
configuration.rb
class Configuration < ActiveRecord::Base
self.table_name = 'configuration'
self.primary_key = :id
belongs_to :console_system, :class_name => 'ConsoleSystem', primary_key: :id, foreign_key: :system_id
belongs_to :cloud_user, :class_name => 'CloudUser', primary_key: :username, foreign_key: :creator
belongs_to :device, :class_name => 'Device', primary_key: :id, foreign_key: :device_id
belongs_to :console_game, :class_name => 'ConsoleGame', primary_key: :id, foreign_key: :console_game_id
scope :by_system,->(system){
system_ids = ConsoleSystem.where(value: system).pluck(:id)
where(system_id: system_ids)
}
scope :by_user,->(user){
user_ids = CloudUser.where(username: user).pluck(:username)
where(creator: user_ids)
}
scope :by_device,->(device){
device_ids = Device.where(name: device).pluck(:id)
where(device_id: device_ids)
}
scope :by_game,->(game){
game_ids = ConsoleGame.where(value: game).pluck(:id)
where(console_game_id: game_ids)
}
class Entity < Grape::Entity
expose :id
expose :value
expose :device_id, :as => :device, using: Device::Entity
expose :system_id, :as => :console_system, using: ConsoleSystem::Entity
expose :console_game_id, :as => :console_game, using: ConsoleGame::Entity
expose :creator, :as => :creator, using: CloudUser::Entity
expose :created_date
expose :positive_votes
expose :negative_votes
end
end
葡萄 API
resource :configuration do
desc "Returns all configurations."
get do
configs = Configuration.includes(:device, :console_system, :cloud_user, :console_game)
present :data, configs, :with => Configuration::Entity
present :status, "Success"
end
end
错误
/configuration 中的 NoMethodError 4:Fixnum 的未定义方法“id”
Ruby /Library/Ruby/Gems/2.0.0/gems/grape-entity-0.4.2/lib/grape_entity/entity.rb：在delegate_attribute，第465行 Web GET 本地主机/配置
删除 :using 以使其“工作”
configuration.rb
class Entity < Grape::Entity
expose :id
expose :value
expose :device_id, :as => :device#, using: Device::Entity
expose :system_id, :as => :console_system#, using: ConsoleSystem::Entity
expose :console_game_id, :as => :console_game#, using: ConsoleGame::Entity
expose :creator, :as => :creator#, using: CloudUser::Entity
expose :created_date
expose :positive_votes
expose :negative_votes
end
JSON 结果
{
data: [
{
id: 1,
value: "configuration data 1 example",
device: 4,
console_system: 1,
console_game: 1,
creator: "manster",
created_date: null,
positive_votes: 0,
negative_votes: 0
},
{
id: 2,
value: "configuration data 2 example",
device: 4,
console_system: null,
console_game: 2,
creator: "Zombieguy",
created_date: null,
positive_votes: 0,
negative_votes: 0
},
{
id: 3,
value: "configuration data 3 example",
device: 4,
console_system: null,
console_game: 3,
creator: "Justin13692",
created_date: null,
positive_votes: 0,
negative_votes: 0
}
],
status: "Success"
}
期望的结果
{
data: [
{
id: 1,
value: "configuration data 1 example",
device: {
id: 4,
device: "XIM Edge"
},
console_system: {
id: 1,
console_system: "Xbox 360"
}
console_game: {
id: 1,
console_game: "Gears of War 3"
},
creator: {
username: "manster",
email: null,
first_name: null,
last_name: null
},
created_date: null,
positive_votes: 0,
negative_votes: 0
},
{
id: 2,
value: "configuration data 2 example",
device: {
id: 4,
device: "XIM Edge"
},
console_system: null,
console_game: {
id: 2,
console_game: "Battlefield 3"
},
creator: {
username: "Zombieguy",
email: null,
first_name: null,
last_name: null
},
created_date: null,
positive_votes: 0,
negative_votes: 0
},
{
id: 3,
value: "configuration data 3 example",
device: {
id: 4,
device: "XIM Edge"
},
console_system: null,
console_game: {
id: 3,
console_game: "Call of Duty: Modern Warfare 3"
},
creator: {
username: "Justin13692",
email: null,
first_name: null,
last_name: null
},
created_date: null,
positive_votes: 0,
negative_votes: 0
}
],
status: "Success"
}
【问题讨论】：
标签： ruby activerecord grape grape-api grape-entity