Rails Rest-Post Params hash not written

Question

I m building my first REST API using Rails and have a simple question which I am unable to solve.

Basically i am not able to write a params hash into the database from a http PUSH request.

I have the following user controller under the Api namespace with the create action.

class Api::UserController < ApplicationController
      http_basic_authenticate_with :name => "test", :password => "test"
      skip_before_action :verify_authenticity_token

      def create
             @user = User.create(params[:user])
              respond_to do |format|
                      if @user.save
                              format.json{render json: @user, status: :created, location: @user} #render create full response
                      else
                              format.json{render json: @user.errors, status: :unprocessable_entity}
                      end
              end
      end
end 

The route to this action is

 POST    /api/user(.:format)    api/user#create{:format=>"json"}

The user model has a name and a address string not contained.

To test the REST call i setup the firefox plugins RESTeasy and RESTclient with this URL http://localhost:3000/api/user/

and this body { "name": "timoteo", "address": "berlin" }

So far so good. Now after sending this package Webrick gives me this output:

Started POST "/api/user" for ::1 at 2015-08-03 17:06:50 +0200
Processing by Api::UserController#create as JSON
 Parameters: {"name"=>"timoteo", "address"=>"berlin"}
  (1.2ms)  BEGIN
  SQL (0.6ms)  INSERT INTO "users" ("created_at", "updated_at") VALUES ($1, $2) RETURNING "id"  [["created_at", "2015-08-03 15:06:50.646169"], ["updated_at", "2015-08-03 15:06:50.646169"]]
  (42.8ms)  COMMIT
  (0.3ms)  BEGIN
  (0.3ms)  COMMIT
 Completed 201 Created in 66ms (Views: 1.4ms | ActiveRecord: 48.1ms)

neglecting the two parameter and an empty empty record like this one gets stored in the database(also the REST clients show me the same)

{"id":19,"name":null,"address":null,"created_at":"2015-08-03T15:06:50.646Z","updated_at":"2015-08-03T15:06:50.646Z"}

Can someone give me a hint what might have gone wrong during the way. I assume it is something with the params hash but i could not figure it out yet.

Answer 1

Add validation to your model:

class User < ActiveRecord::Base
   validates_presence_of :name
   validates_presence_of :address
end

That will disallow saving record with blank attributes.

Then, change your #save call to #persisted? in your controller (because record is created immediately after #create is called, it is already saved or failed)

if @user.persisted?
  format.json{render json: @user, status: :created, location: @user} #render create full response
else
  format.json{render json: @user.errors, status: :unprocessable_entity}
end

UPD . You could also benefit from whitelisting parameters which you accept:

@user = User.create(params.require(:name, :address))

This way Rails will respond with error, saying parameter is missing, and will not assign any other attributes to user (which you don't want to be assigned).

Answer 2

Your params of { "name": "timoteo", "address": "berlin" } are incorrect when your user creation is @user = User.create(params[:user])

You params should look more like: { "user": { "name": "timoteo", "address": "berlin" } } because you're accessing params[:user] so the user attributes need to belong to the user section of your params.

Adding Validations may help if its incorrect to save a User with no name/address too.

class User < ActiveRecord::Base
  validates :name, presence: true
  validates :address, presence: true
  # etc...
end