CODEWITHSUNDEEP
ruby-on-railsjsoninheritancerablinherited-resources
JJD
JJD

Reputation: 51824

Rails: Rabl template with inheritance model structure

I am working on a project which uses some inheritance structure ... The base class is ..

# /app/models/shape.rb
class Shape < ActiveRecord::Base
  acts_as_superclass # https://github.com/mhuggins/multiple_table_inheritance
end

A subclass is ...

# /app/models/circle.rb
class Circle < ActiveRecord::Base
  inherits_from :shape
end

Here is a graphic showing the inheritance structure.

Class model

For these models I am trying to create an API using the RABL gem. Here are the relevant controllers ...

# /app/controllers/api/v1/base_controller.rb
class Api::V1::BaseController < InheritedResources::Base
  load_and_authorize_resource
  respond_to :json, except: [:new, :edit]
end

...

# /app/controllers/api/v1/shapes_controller.rb
class Api::V1::ShapesController < Api::V1::BaseController
  actions :index
  end
end

...

# /app/controllers/api/v1/circles_controller.rb
class Api::V1::CirclesController < Api::V1::BaseController
  def index
    @circles = Circle.all
  end
  def show
    @circle = Circle.find(params[:id])
  end
end

I created a show template as suggested in Railscast #322 of Ryan Bates. It looks like this ...

# /app/views/circles/show.json.rabl
object @circle
attributes :id

When I request a circle via http://localhost:3000/api/v1/circles/1.json the following error message is shown ...

Template is missing

Missing template api/v1/circles/show, api/v1/base/show, inherited_resources/base/show, application/show with {:locale=>[:en], :formats=>[:html], :handlers=>[:erb, :builder, :arb, :haml, :rabl]}.

How do I need to setup the templates in order to work with the inherited resources?

Partial success

I came up with the following views. I also managed to implement the inheritance structure of the models to keep the code DRY.

# views/api/v1/shapes/index.json.rabl
collection @shapes
extends "api/v1/shapes/show"

...

# views/api/v1/shapes/show.json.rabl
object @place
attributes :id, :area, :circumference

...

# views/api/v1/circles/index.json.rabl
collection @circles
extends "api/v1/circles/show"

...

# views/api/v1/circles/show.json.rabl
object @circle
extends "api/v1/shapes/show"
attributes :radius
if action_name == "show"
  attributes :shapes
end

This outputs the desired JSON for the circles (index action):

# http://localhost:3000/api/v1/cirles.json
[
 {
   "id" : 1,
   "area" : 20,
   "circumference" : 13,
   "radius" : 6
 },
 {
   "id" : 2,
   "area" : 10,
   "circumference" : 4,
   "radius: 3
 }
]

But it does not output the associated shapes with all attributes for some reason ...
Note: There is a association on the Shape model which I did not mention before.

# http://localhost:3000/api/v1/cirles/1.json
{
  "id" : 1,
  "area" : 20,
  "circumference" : 13,
  "radius" : 6,
  "shapes" : [
    {
      "id" : 2,
      "created_at" : "2013-02-09T12:50:33Z",
      "updated_at" : "2013-02-09T12:50:33Z"
    }
  ]
},

Upvotes: 0

Views: 1126

Answers (1)

cbascom
cbascom

Reputation: 766

According to the data you provided, you put the templates in /app/views/circles. The error is telling you that you need to put them in /app/views/api/v1/circles instead I believe.

For the second question, it sounds like you are saying each circle has_many associated shapes. In that case, I believe something like the following should give what you want for views/api/v1/circles/show.json.rabl:

# views/api/v1/circles/show.json.rabl
object @circle
extends 'api/v1/shapes/show'
attributes :radius
child(:shapes) do
  extends 'api/v1/shapes/show'
end

Upvotes: 1

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