I'm following a tutorial on how to create a REST Api using the rails-api gem.
In the tutorial, most of the API logic is encapsulated in the base class file app/controllers/api/v1/api_base_controller.rb
module Api
module V1
class ApiBaseController < ApplicationController
protect_from_forgery with: :null_session
before_action :set_resource, only: [:destroy, :show, :update]
respond_to :json
private
#Returns the resource from the created instance variable
#@return [Object]
def get_resource
instance_variable_get("@#{resource_name}")
end
#Returns the allowed parameters for searching
# Override this method in each API controller
# to permit additional parameters to search on
# @return [Hash]
def query_params
{}
end
#Returns the allowed parameters for pagination
# @return [Hash]
def page_params
params.permit(:page, :page_size)
end
# The resource class based on the controller
# @return [Class]
def resource_class
@resource_class ||= resource_name.classify.constantize
end
# The singular name for the resource class based on the controller
# @return [String]
def resource_name
@resource_name ||= self.controller_name.singularize
end
#Only allow a trusted parameter "white list" through.
# If a single resource is loaded for #create or #update,
# then the controller for the resource must implement
# the method "#{resource_name}_params" to limit permitted
# parameters for the individual model.
def resource_params
@resource_params ||= self.send("#{resource_name}_params")
end
#Use callbacks to share common setup or constraints between actions.
def set_resource(resource = nil)
resource ||= resource_class.find(params[:id])
instance_variable_set("@#{resource_name}", resource)
end
#POST /api/v1/{plural_resource_name}
def create
set_resource(resource_class.new(resource_params))
if get_resource.save
render :show, status: :created
else
render json: get_resource.errors, status: :unprocessable_entity
end
end
#DELETE /api/v1/{plural_resource_name}/:id
def destroy
get_resource.destroy
head :no_content
end
#GET /api/v1/{plural_resource_name}
def index
plural_resource_name = "@#{resource_name.pluralize}"
resources = resource_class.where(query_params).page(page_params[:page]).per(page_params[:page_size])
instance_variable_set(plural_resource_name, resources)
respond_with instance_variable_get(plural_resource_name)
end
#GET /api/v1/{plural_resource_name}/1
def show
respond_with get_resource
end
#PATCH/PUT /api/{plural_resource_name}/1
def update
if get_resource.update(resource_params)
render :show
else
render json: get_resource.errors, status: :unprocessable_entity
end
end
end
end
end
The model controllers inherit from this ApiBaseController
one of the model controllers ( albums_controllers.rb
) looks like this:
module Api
module V1
class AlbumsController < Api::V1::ApiBaseController
private
def album_params
params.require(:album).permit(:title)
end
def query_params
params.permit(:title, :artist_id)
end
end
end
end
I also have this in routes.rb
Rails.application.routes.draw do
namespace :api, defaults: {format: 'json'} do
namespace :v1 do
resources :albums, :artists
end
end
end
when I do http://localhost:3000/api/v1/artists
on the browser, i get this error:
`The action 'index' could not be found for Api::V1::ArtistsController`
I have also noted that the ApplicationController
generated by the rails-api gem inherits from ActionController::API
and not ActionController::Base
but i'm not sure whether this is the problem.
private
methods are not available to subclasses. If you REALLY want to hide all of those methods but make it available to subclasses, use protected
instead.
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