AJAX error 400 bad request - Need to pass parameters from one method to the create method of the same controller

Question

I have two models : User and Record. I used scaffold option to generate both my models. I am working in the partial _form.html.erbof my User model and I wrote some javascript to store some piece of information into a javascript variable named value.

Then I implemented an AJAX call to send the javascript variable to my User Controller. Here is my javascript code :

var value = $('input#quantity').val();

$.ajax({
  url: "/info",
  type: "POST",
  data: {
    value: value
  },
  complete: function(){
    console.log('Congrats');
  }

});

Then in my config route fileI wrote the route like this :

resources :user
resrouces :record


post '/info'=>'users#registration'

And in my User controller I have the following methods :

def registration
    @value = params[:value]
    
    
    render json: 'ok'
  end


  def create
    @user = User.new(user_params)
    
    
    respond_to do |format|
      if @user.save
        format.html { redirect_to @user, notice: 'User was successfully created.' }
        format.json { render :show, status: :created, location: @user }
        Record.create(user: @user, value: @value)
         
      else
        format.html { render :new }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
      format.js
    end
  end

What I would like to do is to create a new Record when creating a new User. This record would have the id of the created User and the attribute value would be equal to @value.

I know and I tried it before that Record.create(user: @user) creates a new Record with the id of the User. It is ok for this part.

My question is how to pass @value from the registration method and to make it available in the create method ?

I've read a lot about models and to write after_create methods....but I don't want to use them. I really need to have the @value variable available in my create method.

I tried to route my AJAX call to the create method but then I have the error 400 : bad request

Answer 1

Error 400 bad request means the server is unable identify data stream sent by the client. Try including dataType:"json" in your ajax post request. Also check this answer 400 Bad request. This could be possible reason for your error.