I have two models Post and Comment
class Post < ActiveRecord::Base
has_many :comments
end
class Comment < ActiveRecord::Base
belongs_to :post
end
How can I get all the posts with comments as below json response:
{
"posts": [
{
"name": "Ruby on Rails",
"comments": [
{
"desc": "awesome"
}
]
},
{
"name": "Java",
"comments": [
{
"desc": "Thanks"
},
{
"desc": "very useful"
}
]
}
]
}
try this, create a index.json.jbuilder in app/views/posts/ ,
and add the following code to it
json.posts #posts do |post|
json.name post.name
json.comments post.comments do |comment|
json.desc comment.desc
end
end
Use activemodel Activemodel Serializers.Also check out this railscasts video which gives you a pretty good idea about activemodel serializers and how to use it Railscasts-activemodel serializers.
Hope i've helped.
Related
In my Rails (api only) learning project, I have 2 models, Group and Artist, that have a many-to-many relationship with a joining model, Role, that has additional information about the relationship. I have been able to save m2m relationships before by saving the joining model by itself, but here I am trying to save the relationship as a nested relationship. I'm using the jsonapi-serializer gem, but not married to it nor am I tied to the JSON api spec. Getting this to work is more important than following best practice.
With this setup, I'm getting a 500 error when trying to save with the following errors:
Unpermitted parameters: :artists, :albums and ActiveModel::UnknownAttributeError (unknown attribute 'relationships' for Group.)
I'm suspecting that my problem lies in the strong param and/or the json payload.
Models
class Group < ApplicationRecord
has_many :roles
has_many :artists, through: :roles
accepts_nested_attributes_for :artists, :roles
end
class Artist < ApplicationRecord
has_many :groups, through: :roles
end
class Role < ApplicationRecord
belongs_to :artist
belongs_to :group
end
Controller#create
def create
group = Group.new(group_params)
if group.save
render json: GroupSerializer.new(group).serializable_hash
else
render json: { error: group.errors.messages }, status: 422
end
end
Controller#group_params
def group_params
params.require(:data)
.permit(attributes: [:name, :notes],
relationships: [:artists])
end
Serializers
class GroupSerializer
include JSONAPI::Serializer
attributes :name, :notes
has_many :artists
has_many :roles
end
class ArtistSerializer
include JSONAPI::Serializer
attributes :first_name, :last_name, :notes
end
class RoleSerializer
include JSONAPI::Serializer
attributes :artist_id, :group_id, :instruments
end
Example JSON payload
{
"data": {
"attributes": {
"name": "Pink Floyd",
"notes": "",
},
"relationships": {
"artists": [{ type: "artist", "id": 3445 }, { type: "artist", "id": 3447 }]
}
}
Additional Info
It might help to know that I was able to save another model with the following combination of json and strong params.
# Example JSON
"data": {
"attributes": {
"title": "Wish You Were Here",
"release_date": "1975-09-15",
"release_date_accuracy": 1
"notes": "",
"group_id": 3455
}
}
# in albums_controller.rb
def album_params
params.require(:data).require(:attributes)
.permit(:title, :group_id, :release_date, :release_date_accuracy, :notes)
end
From looking at https://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html I think the data format that Rails is normally going to expect will look something like:
{
"group": {
"name": "Pink Floyd",
"notes": "",
"roles_attributes": [
{ "artist_id": 3445 },
{ "artist_id": 3447 }
]
}
}
with a permit statement that looks something like (note the . before permit has moved):
params.require(:group).
permit(:name, :notes, roles_attributes: [:artist_id])
I think you have a few options here:
Change the data format coming into the action.
Craft a permit statement that works with your current data (not sure how tricky that is), you can test your current version in the console with:
params = ActionController::Parameters.new({
"data": {
"attributes": {
"name": "Pink Floyd",
"notes": "",
},
"relationships": {
"artists": [{ type: "artist", "id": 3445 }, { type: "artist", "id": 3447 }]
}
}
})
group_params = params.require(:data).
permit(attributes: [:name, :notes],
relationships: [:artists])
group_params.to_h.inspect
and then restructure the data to a form the model will accept; or
Restructure the data before you try to permit it e.g. something like:
def group_params
params_hash = params.to_unsafe_h
new_params_hash = {
"group": params_hash["data"]["attributes"].merge({
"roles_attributes": params_hash["data"]["relationships"]["artists"].
map { |a| { "artist_id": a["id"] } }
})
}
new_params = ActionController::Parameters.new(new_params_hash)
new_params.require(:group).
permit(:name, :notes, roles_attributes: [:artist_id])
end
But ... I'm sort of hopeful that I'm totally wrong and someone else will come along with a better solution to this stuff.
I'm using Netflix's jsonapi-rails gem to serialize my API. I need to build a response.json object that includes the associated comments for a post.
Post model:
class Post < ApplicationRecord
has_many :comments, as: :commentable
end
Polymorphic Comment model
class Comment < ApplicationRecord
belongs_to :commentable, polymorphic: true
end
PostSerializer
class PostSerializer
include FastJsonapi::ObjectSerializer
attributes :body
has_many :comments, serializer: CommentSerializer, polymorphic: true
end
CommentSerializer
class CommentSerializer
include FastJsonapi::ObjectSerializer
attributes :body, :id, :created_at
belongs_to :post
end
Posts#index
class PostsController < ApplicationController
def index
#posts = Post.all
hash = PostSerializer.new(#posts).serialized_json
render json: hash
end
end
What I've got so far only gives me the comment type and id, but I NEED the comment's body as well.
Please help!
Thanks in advance~!
Although not very intuitive this behaviour is there by design. According to the JSON API relationship data and actual related resource data belong in different objects of the structure
You can read more here:
Fetching Relationships
Inclusion of Related Resources
To include the body of the Comments your serializers would have to be:
class PostSerializer
include FastJsonapi::ObjectSerializer
attributes :body, :created_at
has_many :comments
end
class CommentSerializer
include FastJsonapi::ObjectSerializer
attributes :body, :created_at
end
and your controller code:
class HomeController < ApplicationController
def index
#posts = Post.all
options = {include: [:comments]}
hash = PostSerializer.new(#posts, options).serialized_json
render json: hash
end
end
The response for a single Post would look something like this:
{
"data": [
{
"attributes": {
"body": "A test post!"
},
"id": "1",
"relationships": {
"comments": {
"data": [
{
"id": "1",
"type": "comment"
},
{
"id": "2",
"type": "comment"
}
]
}
},
"type": "post"
}
],
"included": [
{
"attributes": {
"body": "This is a comment 1 body!",
"created_at": "2018-05-06 22:41:53 UTC"
},
"id": "1",
"type": "comment"
},
{
"attributes": {
"body": "This is a comment 2 body!",
"created_at": "2018-05-06 22:41:59 UTC"
},
"id": "2",
"type": "comment"
}
]
}
I am using AMS version 0.10 and looking to use the json-api specification for rendering my responses. However, I am having difficultly rendering the 'included' key for my relationship data. I have the following setup:
products_controller.rb
class Api::V1::ProductsController < ApplicationController
...
respond_to :json
def show
respond_with Product.find(params[:id])
end
...
product_serializer.rb
class ProductSerializer < ActiveModel::Serializer
attributes :id, :title, :price, :published
has_one :user
end
user_serializer.rb
class UserSerializer < ActiveModel::Serializer
attributes :id, :email, :auth_token, :created_at, :updated_at
end
products_controller_spec.rb
before(:each) do
#product = FactoryGirl.create :product
get :show, params: { id: #product.id }
end
...
it "has the user as a embeded object" do
product_response = json_response
puts "&&&&&&&&&&&&&&&"
puts product_response #output below
#expect(product_response[:user][:email]).to eql #product.user.email
end
...
json_response
{:data=>{:id=>"1", :type=>"products", :attributes=>{..working..}, :relationships=>{:user=>{:data=>{:id=>"1", :type=>"users"}}}}}
I would like to know how to get the 'included' section for the nested resource.
Example (from http://jsonapi.org/format/#introduction)
{
"data": [{
"type": "articles",
"id": "1",
"attributes": {
"title": "JSON API paints my bikeshed!"
},
"links": {
"self": "http://example.com/articles/1"
},
"relationships": {
"author": {
"links": {
"self": "http://example.com/articles/1/relationships/author",
"related": "http://example.com/articles/1/author"
},
"data": { "type": "people", "id": "9" }
}
}],
"included": [{
"type": "people",
"id": "9",
"attributes": {
"first-name": "Dan",
"last-name": "Gebhardt",
"twitter": "dgeb"
},
"links": {
"self": "http://example.com/people/9"
}
},
I have never used AMS before so any help will be greatly appreciated.
Many thanks
Just for anyone else the solution is here https://github.com/rails-api/active_model_serializers/blob/master/docs/jsonapi/schema.md.
Essentially i add the following to my controller action (GET products/1)
render json: product, include: params[:include]
This will allow the requesting system to determine whether they would like to include the nested models by adding the parameter include='user' for the api to process.
Thanks
I am using active_model_serializers gem for the first time. Version which I'm using is 0.10.2
I have three models with associations like this:
class Song < ActiveRecord::Base
has_many :questions
end
class Question< ActiveRecord::Base
belongs_to :song
has_many :answers
end
class Answer< ActiveRecord::Base
belongs_to :question
end
I've generated three serializers like this:
class SongSerializer < ActiveModel::Serializer
attributes :id, :audio, :image
has_many :questions
end
class QuestionSerializer < ActiveModel::Serializer
attributes :id, :text
belongs_to :song
has_many :answers
end
class AnswerSerializer < ActiveModel::Serializer
attributes :id, :text
belongs_to :question
end
but unfortunately my json response doesn't show me the question's answers, but songs and questions are showing.
after some googling I tried to add
ActiveModelSerializers.config.default_includes = '**'
or from documentation like this:
class Api::SongsController < ApplicationController
def index
songs = Song.all
render json: songs, include: '**' #or with '*'
end
end
but this led me to stack level too deep error
So what should I do in order to get json response to looks like this -
{
"id": "1",
"audio": "...",
"image": "...",
"questions": [
{
"id": "1",
"text": ".....",
"answers": [
{
"id": "1",
"text": "...."
},
{
"id": "2",
"text": "..."
}
]
},
{
"id": "2",
"text": "....."
}
]
}
because simply adding associations like I would do in models are not helping for the third association.
Any help would be appreciated!
So finally after some more searching I found solution which worked. I had to add to my controller include with nested models.
class Api::SongsController < ApplicationController
def index
songs = Song.all
render json: songs, include: ['questions', 'questions.answers']
end
end
And it worked like a charm!
You can do it in your controller with the following structure
respond_with Song.all.as_json(
only: [ :id, :audio, :image ],
include: [
{
questions: {
only: [:id, :text],
include: {
anwers: {
only: [ :id, :text ]
}
}
}
}
]
)
I am trying to use custom serializers for the relationships in a serializer and the json_api adapter enabled. However the relationships are not serialized correctly (or, better, not at all displayed/serialized).
PostController.rb
def index
render json: Post.all, each_serializer: Serializers::PostSerializer
end
Serializer
module Api
module V1
module Serializers
class PostSerializer < ActiveModel::Serializer
attributes :title, :id
belongs_to :author, serializer: UserSerializer
has_many :post_sections, serializer: PostSectionSerializer
end
end
end
end
JSON output:
{
"data": [
{
"attributes": {
"title": "Test Title"
},
"id": "1",
"relationships": {
"author": {
"data": {
"id": "1",
"type": "users"
}
},
"post_sections": {
"data": [
{
"id": "1",
"type": "post_sections"
}
]
}
},
"type": "posts"
}
]
}
As you can see, the relationships are not fulfilled, which happens only if I specify a custom serializer for the relationships!!
If I do something like this:
module Api
module V1
module Serializers
class PostSerializer < ActiveModel::Serializer
attributes :title, :id
belongs_to :author # no custom serializer!
has_many :post_sections # no custom serializer!
end
end
end
end
The relationships are shown correctly, but not using a custom serializer...
What's the issue here ?
EDIT
According to the json API 1.0 Format, what I am getting back is the so-called resource identifier object.
The following primary data is a single resource identifier object that
references the same resource:
{ "data": {
"type": "articles",
"id": "1" } }
Is there a way to prevent getting resource identifier objects, and get the actual data instead ?
Relationships only returns id and type according to json-api exmaples. If you need to return more information about this relation you should add include option on your render action.
Ex.
PostController.rb
class PostsController < ApplicationController
def show
render json: #post, include: 'comments'
end
end
Serializers
class PostSerializer < ActiveModel::Serializer
attributes :id, :title, :content
has_many :comment, serializer: CommentSerializer
end
class CommentSerializer < ActiveModel::Serializer
attributes :id, :title, :content
end
JSON output:
{
"data": {
"id": "1",
"type": "post",
"attributes": {
"title": "bla",
"content": "bla"
},
"relationships": {
"comment": {
"data": [
{
"type": "comments",
"id": "1"
}
]
}
}
},
"included": {
{
"id": "1",
"type": "comments",
"attributes": {
"title": "test",
"content": "test"
}
}
]
}
Just to add to #Bruno Bacarini's answer, you may also include chained associations by using:
render #posts, include: ['authors.profile', 'comments']
source: joaomdmoura's comment on github