我有以下路线
resources :continent do
resources :countries do
resource :cities do
resource :streets
end
end
end
选择我必须做的国家
/continents/:continent_id/countries/:country_id
等等。
我的问题是如何才能获得特定国家或大陆的所有街道。或者特定大陆的所有国家。
例如，有没有办法
/continents/:continent_id/countries/cities
将返回以下所有城市：continent_id
答案 0 :(得分：3)
资源不应该嵌套超过1级深度。请参阅：http://weblog.jamisbuck.org/2007/2/5/nesting-resources
如果你确实需要这种深度，那么你可以用浅属性设置为true来解决这个问题。 请参阅：http://edgeguides.rubyonrails.org/routing.html#shallow-nesting
更新以更好地解释浅嵌套的使用
rails new shallow-routes
cd shallow-routes
修改config/routes.rb以添加所需的路线
resources :continent do
resources :countries do
resource :cities do
resource :streets
end
end
end
现在正在运行rake routes我们有这个：
Prefix Verb URI Pattern Controller#Action
continent_country_cities_streets POST /continent/:continent_id/countries/:country_id/cities/streets(.:format) streets#create
new_continent_country_cities_streets GET /continent/:continent_id/countries/:country_id/cities/streets/new(.:format) streets#new
edit_continent_country_cities_streets GET /continent/:continent_id/countries/:country_id/cities/streets/edit(.:format) streets#edit
GET /continent/:continent_id/countries/:country_id/cities/streets(.:format) streets#show
PATCH /continent/:continent_id/countries/:country_id/cities/streets(.:format) streets#update
PUT /continent/:continent_id/countries/:country_id/cities/streets(.:format) streets#update
DELETE /continent/:continent_id/countries/:country_id/cities/streets(.:format) streets#destroy
continent_country_cities POST /continent/:continent_id/countries/:country_id/cities(.:format) cities#create
new_continent_country_cities GET /continent/:continent_id/countries/:country_id/cities/new(.:format) cities#new
edit_continent_country_cities GET /continent/:continent_id/countries/:country_id/cities/edit(.:format) cities#edit
GET /continent/:continent_id/countries/:country_id/cities(.:format) cities#show
PATCH /continent/:continent_id/countries/:country_id/cities(.:format) cities#update
PUT /continent/:continent_id/countries/:country_id/cities(.:format) cities#update
DELETE /continent/:continent_id/countries/:country_id/cities(.:format) cities#destroy
continent_countries GET /continent/:continent_id/countries(.:format) countries#index
POST /continent/:continent_id/countries(.:format) countries#create
new_continent_country GET /continent/:continent_id/countries/new(.:format) countries#new
edit_continent_country GET /continent/:continent_id/countries/:id/edit(.:format) countries#edit
continent_country GET /continent/:continent_id/countries/:id(.:format) countries#show
PATCH /continent/:continent_id/countries/:id(.:format) countries#update
PUT /continent/:continent_id/countries/:id(.:format) countries#update
DELETE /continent/:continent_id/countries/:id(.:format) countries#destroy
continent_index GET /continent(.:format) continent#index
POST /continent(.:format) continent#create
new_continent GET /continent/new(.:format) continent#new
edit_continent GET /continent/:id/edit(.:format) continent#edit
continent GET /continent/:id(.:format) continent#show
PATCH /continent/:id(.:format) continent#update
PUT /continent/:id(.:format) continent#update
DELETE /continent/:id(.:format) continent#destroy
让我们更改用于浅嵌套的资源并查看结果
resources :continent, shallow: true do
resources :countries do
resource :cities do
resource :streets
end
end
end
结果
Prefix Verb URI Pattern Controller#Action
country_cities_streets POST /countries/:country_id/cities/streets(.:format) streets#create
new_country_cities_streets GET /countries/:country_id/cities/streets/new(.:format) streets#new
edit_country_cities_streets GET /countries/:country_id/cities/streets/edit(.:format) streets#edit
GET /countries/:country_id/cities/streets(.:format) streets#show
PATCH /countries/:country_id/cities/streets(.:format) streets#update
PUT /countries/:country_id/cities/streets(.:format) streets#update
DELETE /countries/:country_id/cities/streets(.:format) streets#destroy
country_cities POST /countries/:country_id/cities(.:format) cities#create
new_country_cities GET /countries/:country_id/cities/new(.:format) cities#new
edit_country_cities GET /countries/:country_id/cities/edit(.:format) cities#edit
GET /countries/:country_id/cities(.:format) cities#show
PATCH /countries/:country_id/cities(.:format) cities#update
PUT /countries/:country_id/cities(.:format) cities#update
DELETE /countries/:country_id/cities(.:format) cities#destroy
continent_countries GET /continent/:continent_id/countries(.:format) countries#index
POST /continent/:continent_id/countries(.:format) countries#create
new_continent_country GET /continent/:continent_id/countries/new(.:format) countries#new
edit_country GET /countries/:id/edit(.:format) countries#edit
country GET /countries/:id(.:format) countries#show
PATCH /countries/:id(.:format) countries#update
PUT /countries/:id(.:format) countries#update
DELETE /countries/:id(.:format) countries#destroy
continent_index GET /continent(.:format) continent#index
POST /continent(.:format) continent#create
new_continent GET /continent/new(.:format) continent#new
edit_continent GET /continent/:id/edit(.:format) continent#edit
continent GET /continent/:id(.:format) continent#show
PATCH /continent/:id(.:format) continent#update
PUT /continent/:id(.:format) continent#update
DELETE /continent/:id(.:format) continent#destroy
为了更好地观看http://i.imgur.com/21CEM7j.png
，它的图像有所不同我们这里有的是现在路线更简单，像/continent/:continent_id/countries这样的路线现在仅存在于索引，创建和新，其他路线不在大陆范围中路由
请注意，它确实非常有用，因为您不需要路线来告诉您街道位于大陆内部，很明显，如果您的街道位于城市内部，那么它就是当然，在一个国家和大陆之内。
直接回答 - 现在让我们来看看你的目标
/大洲/：continent_id /国家/城市
你想要非洲大陆的所有城市，为什么[地狱，对不起]你需要他们之间的国家吗？
我会做/continents/:id/cities，更简单易懂。
要实现这一点，您只需在大陆资源中创建一条新路线
resources :continent, shallow: true do
member do
get 'cities'
end
resources :countries do
resource :cities do
resource :streets
end
end
end
然后你有了这个新的好路线
cities_continent GET /continent/:id/cities(.:format) continent#cities
答案 1 :(得分：1)
您可以使用以下模型关系
class Country < ActiveRecord::Base
has_many :streets, :through => : cities
end
因此，您可以在代码中使用
Country.find(1).streets