What does redirecting to an instance mean in Ruby on Rails

Question

What does redirecting to a particular instance mean? I am aware of how the redirecting works.

class UsersController < ApplicationController

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if @user.save
      log_in @user
      flash[:success] = "Welcome to the Sample App!"
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
    @user = User.find(params[:id])
  end

  private

    def user_params
      params.require(:user).permit(:name, :email, :password,
                                   :password_confirmation)
    end
end

I understand the following ways of redirecting:

• redirect_to :new (redirect to new method and displaying the new.html.erb file)
• redirect_to "show" (redirect to show.html.erb file or the path for show method)

but what does redirect_to @user mean? Which method and path are we are redirecting to?

Answer 1

If you check the redirect_to documentation, you will find this.

Record - The URL will be generated by calling url_for with the options , which will reference a named URL for that record.

Answer 2

It's Rails "magic" for redirecting to the #show action for that @user using GET . You'll find similar things in default Rails forms as well, but for actions like POST .

Answer 3

According to section 7.4.1 from Michael Hartl's The Rails Tutorial :

redirect_to @user

can be written instead of

redirect_to user_url(@user)

Quoting Michael Hartl:

This is because Rails automatically infers from redirect_to @user that we want to redirect to user_url(@user) .