NoMethodError in Users#index 'undefined method `each' for nil:NilClass'

Question

I'm getting a NoMethodError in Users#Index with an 'undefined method `each' for nil:NilClass' for the line below:

<% @users.each do |user| %>

I'm not sure where the problem resides. Any help is greatly appreciated. Thanks in advance. I know I am missing something extremely easy here.

User/Index

<div class="page-header">
<center><strong><h1> All Users </h1></strong></center>
</div>

    <div class="row">
        <% @users.each do |user| %>
        <div class="horizontal-align col-md-2">
            <div class="user">
                <center><%= link_to image_tag(user.avatar.url(:thumb)), user %></center>
                <center><br><%= link_to user.name, user %></br></center>
                <% if current_user.admin %>
                <center><%= link_to "Delete", user, method: :delete, data: { confirm: "Are you sure?" } %></center>
                <% end %>
            </div>
        </div>
        <% end %>
    </div>
</div>

<div class="center">
<%= will_paginate @users, renderer: BootstrapPagination::Rails %>
</div>
</div>

User/Show

<% provide(:title, @user.name) %>

 <div class="row">
    <aside class="span4">
        <section>
            <h1>
                <%= image_tag @user.avatar.url(:thumb) %>
                <%= @user.name %>
            </h1>


    <section>
      <%= render 'users/stats' %>
    </section>


    <% if current_user.following?(@user) %>
    <%= render 'users/unfollow' %>
    <% else %>
    <%= render 'users/follow' %>
    <% end %>

User/Controller

    class UsersController < ApplicationController

  before_action :correct_user, only: [:edit, :update, :destroy]
  before_action :authenticate_user!, except: [:index, :show]
  before_action :admin_user,     only: :destroy


   def following
    @title = "Following"
    @user = User.find(params[:id])
    @users = @user.followed_users.paginate(page: params[:page])
    render 'show_follow'
   end

  def followers
    @title = "Followers"
    @user = User.find(params[:id])
    @users = @user.followers.paginate(page: params[:page])
    render 'show_follow'
  end


  def index
    @users = User.paginate(page: params[:page], :per_page => 20)
  end


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

    if @user 

      @posts = @user.posts.order("updated_at DESC")
      render actions: :show
    else
      render file: 'public/404', status: 404, formats: [:html]
  end  
  end

  def destroy
    User.find(params[:id]).destroy
    flash[:success] = "Your account has been deleted."
    redirect_to root_path
  end

  def correct_user
      @user = User.find(params[:id])
      redirect_to root_path 
  end

  def admin_user
      redirect_to root_path unless current_user.admin?
  end

end

Answer 1

The error NoMethodError means that you are calling a method that doesn't exist for the given class. In this case it is nil:NilClass which, obvious, doesn't contain the method each because it is nil! So let's examine:

You are calling @users.each which is calling the error. Since it says that the method if undefined for nil (as described above) it tells us that on the index page, @users is nil (probably not what it is intended to be!).

So it looks like the problem rests in your definition of @users. I'm not entirely sure, but it looks as though, in your UsersController that you have an extra end after the def following which would cause the controller to end prematurely, and therefore not define @users. (You can test that by changing it to @users = User.all which should work).

Let me know how things turn out