Undefined method [model]_url for nested resource

Question

I am working on a nested resources project, and am getting an error in my steps controller:

  def create
    @step = Step.new(step_params)

    respond_to do |f|
      if @step.save
        f.html { redirect_to @step, notice: 'Step was successfully created.' }
        f.json { render action: 'show', status: :created, location: @step }
      else
        f.html { render action: 'new' }
        f.json { render json: @step.errors, status: :unprocessable_entity }
      end
    end
  end

The error I am getting is:

undefined method `step_url' for #<StepsController:0x007feeb6442198>

My routes looks like this:

root 'lists#index'

resources :lists do
  resources :steps
end

Answer 1

As you are using nested resources, update the create action as below:

  def create
    @list = List.find(params[:list_id])
    @step = @list.steps.build(step_params) ## Assuming that list has_many steps

    respond_to do |f|
      if @step.save
        ## update the url passed to redirect_to as below
        f.html { redirect_to list_step_url(@list,@step), notice: 'Step was successfully created.' }
        f.json { render action: 'show', status: :created, location: @step }
      else
        f.html { render action: 'new' }
        f.json { render json: @step.errors, status: :unprocessable_entity }
      end
    end
  end

Run rake routes to see the available routes. As route to steps#show would look something like

GET lists/:list_id/steps/:id steps#show

Use list_step_url with 2 arguments @list For :list_id and @step for :id to go to show page of Step.