Nesting :json include in Rails

Question

I have three models:

class A < ActiveRecord::Base
  has_many :bs
end

class B < ActiveRecord::Base
  has_one :c
  belongs_to :a
end

class C < ActiveRecord::Base
  belongs_to :b
end

I want to get json data containing all B's and C's for an A. I tried a number of things similar to:

render json: @as, :include => [:bs => [:include=>[:c]]

but nothing works. What would be a good way to do this.

Jordan Running · Accepted Answer · 2014-01-14 16:37:18Z

51

Refer to ActiveModel::Serializers::JSON#as_json to see the options you can pass to render :json. To quote:

To include associations use :include ...

Second level and higher order associations work as well:

user.as_json(:include => { :posts => {
                             :include => { :comments => {
                                             :only => :body } },
                             :only => :title } })
# => { "id": 1, "name": "Konata Izumi", "age": 16,
#      "created_at": "2006/08/01", "awesome": true,
#      "posts": [ { "comments": [ { "body": "1st post!" }, { "body": "Second!" } ],
#                   "title": "Welcome to the weblog" },
#                 { "comments": [ {"body": "Don't think too hard" } ],
#                   "title": "So I was thinking" } ]
#    }

It's not necessary to call to_json or as_json directly, as render :json does it automatically.

edited Jan 14, 2014 at 16:37

answered Apr 2, 2012 at 20:55

Jordan Running

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4 Comments

Don Kirkby Over a year ago

If you're stuck in Rails 2, render() doesn't support :include, but to_json() does. In that case, it makes sense to call render :json => @as.to_json(:include => :bs).

Albert.Qing Over a year ago

to_json sometimes break the nest struct

Jordan Running Over a year ago

@Albert.Qing If you're having a specific problem you should post it as a new question.

Albert.Qing Over a year ago

@Jordan Here is Question about this

Arslan Ali · Accepted Answer · 2015-06-12 07:11:48Z

9

You need to pass in hash instead of array

render :json => @as.to_json(:include => { :bs => {:include =>:c} })

edited Jun 12, 2015 at 7:11

Arslan Ali

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answered Apr 2, 2012 at 21:21

Abid

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Comments

xeitor · Accepted Answer · 2021-05-23 15:57:45Z

6

For those looking to do the same thing but with ruby's new syntax instead, it would be something like this

render json: @as.to_json(include: { bs: { include: :c}})

And to extract only some attributes:

render json: @a.to_json(only: [:name, :phone, :phone_mobile], include: { bs: { only: :email, include: {c: {only: [:id, :name]}}}})

answered May 23, 2021 at 15:57

xeitor

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Comments

Frederick Cheung · Accepted Answer · 2012-04-02 20:41:50Z

2

Try

render :json => @as.to_json(:include => {:bs => :c})

answered Apr 2, 2012 at 20:41

Frederick Cheung

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Comments

FelixSFD · Accepted Answer · 2017-02-16 19:59:21Z

2

Try this:

render json: @tiquets, :include => { :enterprise => {:include => { :location => {:only => :lo_name } },:only => :en_name } } }

edited Feb 16, 2017 at 19:59

FelixSFD

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answered Feb 16, 2017 at 17:13

Julian Botia

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4 Comments

FelixSFD Over a year ago

@OwaisKureshi A code-only answer might not be a good one, but it's still an answer. I would recommend you this post about the LQPRQ: You're doing it wrong: A plea for sanity in the Low Quality Posts queue

DayTimeCoder Over a year ago

@FelixSFD , Well I agree, but there should be some text explaining the answer, or he can just post this as a comment?

FelixSFD Over a year ago

@OwaisKureshi It's recommended and preferable to explain the code a bit. But even without explanation, this is an answer.

DayTimeCoder Over a year ago

@FelixSFD Alright I got your point, thanks for explaining, I have retracted my comment.

bluish · Accepted Answer · 2012-07-16 08:19:51Z

0

Try this:

render json: @as.to_json(include:{bs: {include:{c:}}})

edited Jul 16, 2012 at 8:19

bluish

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answered Apr 17, 2012 at 10:46

Kuberan

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