工作如何在控制器中呈现动作？

Question

I have method in controller like this:

  def create
    @player = Player.new(player_params)
    if @player.save
      flash[:success] = "Player created"
      redirect_to player_path(@player)
    else
      render 'new'
    end
  end

And I have also test:

it "add players without nickname" do
  visit new_player_path
  click_button "Add player"
  current_path should eq new_player_path
end

But after call render method my current path is:

http://localhost:3000/players

not

http://localhost:3000/players/new

But the layout is from players/new . Why? And what should be my test? In test I just want to check if user don't type in nickname in nickname filed application return to create user page (players/new path).

Answer 1

Actually when there is any errors then it moves from new to create action, so the path becomes http://localhost:3000/players , and the render just renders the new action's template here. Now the main question is why so?

As in the new action you have submitted the form with some data to the create action. Now if suppose it sends you back to new action then it would have to redirect you back to that page, so what will redirect do? It will make rails to loose all the form data which you have submitted and the data would never persist. So instead what is done is you remain on the create action which has the url: http://localhost:3000/players and it renders the new action which means the new action's template (or you can say form). It doesn't redirects it just renders it in the same one.

Now the question is how does the data persist? The data persists with the object. This line @player = Player.new(player_params) creates a new object of the Player class with the attributes you have passed in the form. Now as you remain in the same action and the object is persisted so the data on the form is also persisted.

If you want to test it then in your code replace this:

render 'new'

with:

redirect_to new_player_path

and you will notice the data would never persist unless you pass that explicitly.

Hope this helps.