Rails的对象关系和JSON渲染对象、关系、Rails、JSON
免责声明，我不是很了解Rails的。我会尽量简洁。 考虑下面的模型关系的Rails：
类MODELA＆LT;的ActiveRecord :: Base的
belongs_to的：ModelB
...
一流的ModelB＆LT;的ActiveRecord :: Base的
的has_many：MODELA
当调用MODELA控制器返回的JSON的表演动作应该显示是对象B，其中的对象A的问题是一个孩子的孩子们ObjectAs。
所以，如果我有一个包含对象A的ID 1,2和3，然后访问的对象B：/modela/1.json
我应该看到：
{
modelb：{
ID：1，
MODELA：[插入MODELA JSON的ID的1，2和3]
}
}
解决方案
在默认情况下，你得到的就只是这重新presents modelb 在上面的例子中JSON 。但是，你可以告诉Rails包括其它相关的对象，以及：
高清输出
@export_data = ModelA.find（PARAMS [：ID]）
respond_to代码做|格式|
的format.html
format.json {渲染：JSON =＆GT; @ export_data.to_json（：包括=＆GT;：modelb）}
结束
结束
您甚至可以告诉它排除某些领域，如果你不希望看到他们在出口：
渲染：JSON =＆GT; @ export_data.to_json（：包括=＆GT; {：modelb =＆GT; {：除了=＆GT; [：created_at，的updated_at]}}）
或者，只包括某些字段：
渲染：JSON =＆GT; @ export_data.to_json（：包括=＆GT; {：modelb =＆GT; {：只=＆GT;：名}}）
你可以嵌套这些深深为你需要（让我们说，ModelB也HAS_MANY ModelC）：
渲染：JSON =＆GT; @ export_data.to_json（：包括=＆GT; {：modelb =＆GT; {：包括=＆GT;：modelc}}）
Disclaimer, I know very little about Rails. I'll try to be succinct. Given the following model relations in Rails:
class ModelA < ActiveRecord::Base
belongs_to :ModelB
...
class ModelB < ActiveRecord::Base
has_many :ModelA
When calling the show action of the ModelA controller the returned JSON should show all ObjectAs that are children of the ObjectB of which the ObjectA in question is a child of.
So if I have an ObjectB that contains ObjectA's of ID 1, 2 and 3 and then access: /modela/1.json
I should see:
{
"modelb": {
"id": "1",
"modela": [insert the ModelA JSON for ID's 1, 2 and 3]
}
}
解决方案
By default you'll only get the JSON that represents modelb in your example above. But, you can tell Rails to include the other related objects as well:
def export
@export_data = ModelA.find(params[:id])
respond_to do |format|
format.html
format.json { render :json => @export_data.to_json(:include => :modelb) }
end
end
You can even tell it to exclude certain fields if you don't want to see them in the export:
render :json => @export_data.to_json(:include => { :modelb => { :except => [:created_at, updated_at]}})
Or, include only certain fields:
render :json => @export_data.to_json(:include => { :modelb => { :only => :name }})
And you can nest those as deeply as you need (let's say that ModelB also has_many ModelC):
render :json => @export_data.to_json(:include => { :modelb => { :include => :modelc }})
