Question

So I have seen other articles here on stack about this and a lot of the time people are not doing @post = post.new. I read some where to use the plural…??

any ways I am getting this error on my discussion code:

Model

class Discussion < ActiveRecord::Base
  has_many :comment
  belongs_to :author
  attr_accessible :author_id, :content, :title

  validate :comment, :presence => true
  validate :title, :presence => true
end

Discussion Controller

class DiscussionsController < ApplicationController
  def index
    @discussion = Discussion.new
    @discussions = Discussion.all
  end

  def create
    @discussion = Discussion.create(params[:discussion])
    if @discussion.save
      redirect_to tasks_path, :flash => {:success => 'Created a new discussion'}
    else
      redirect_to tasks_path, :flash => {:error => 'Failed to create a discussion'}
    end
  end
end

Discussion Form

<%= form_for @discussion do |f| %>

    <p><%= f.label :title %>
    <%= f.text_field :title %></p>

    <p><%= f.label :content %>
    <%= f.text_area :content %></p>

<% end %>

Discussion Routes

  resources :discussions do
    resources :comments
  end

Now as far as I know I am doing this right, because I have a task form set up essentially the same way – but I have looked at my code for hours and have googled and tried other examples and now i see this:

undefined method `model_name' for NilClass:Class

Extracted source (around line #1):

1: <%= form_for @discussion do |f| %>
2: 
3:  <p><%= f.label :title %>
4:  <%= f.text_field :title %></p>

Which should mean that I am missing something from my controller…..is it as asilly as a spelling mistake? >.>

Answer 1

I believe your problem is that you are trying to create a discussion on a task form but have only defined the discussion controller and not the task controller.