Question

Ok, been staring at this for two hours now.

I’m experimenting with an empty form in HAML in views/categories/index.html.haml

=form_for @categories do |f|
  =f.submit

my categories_controller.rb looks like…

class CategoriesController < ApplicationController
  # GET /categories
  # GET /categories.json
  def index
    @categories = Category.all

    respond_to do |format|
      format.html # index.html.haml
      format.json { render json: @categories }
    end
  end
end

I’m getting… NoMethodError in Categories#index
undefined method `model_name’ for NilClass:Class

I know this is easy but my mind is mush right now.

Answer 1

You have to use form_for method for a specific model, not for an array of them, like:

- @categories.each do |category|
    = form_for category do |f|
        = f.submit

And your error seems like is showing you that you don’t have any records in your categories table. Otherwise the complain would have been different 🙂