CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-4
Pavarine
Pavarine

Reputation: 726

Error: undefined method `each' for nil:NilClass

I'm getting the this error: undefined method `each' for nil:NilClass when trying to render choose_album_to_add.html.erb :

<table class="table_">
  <thead>
    <tr>
      <th>Album</th>
    </tr>
  </thead>

  <tbody>
    <% @albums.each do |album| %>
      <tr>
        <td><%= album.name %></td>
      </tr>
    <% end %>
  </tbody>
</table>

<br>

my users_controller.rb

def choose_album_to_add
       @albums = Album.all
end

What could be wrong? Edit

As asked, I'm sure that my view file choose_album_to_add.html.erb is in /app/views/users . And I've a route like this:

match '/addAlbum/:id', to: 'users#choose_album_to_add', via: 'get'

Of course, I'm typing /addAlbum/45 on Browser, and it routes properly. The view is also loaded for sure, but the problem is that the instance vars that I declared on my controller can't be accessed on my view . =[

I've scaffolded four resources and they're working fine following this conventions of declaring instance variables and using then in views. I know there are alternative ways ( like passings locals ) but I want to do the job this way.

The log from the console when tryng to access

Started GET "/addAlbum/50" for 127.0.0.1 at 2014-03-24 09:56:13 -0400
Processing by UsersController#choose_album_to_add as HTML
  Parameters: {"id"=>"50"}
  Rendered users/choose_album_to_add.html.erb within layouts/application (1.0ms)
Completed 500 Internal Server Error in 3ms

ActionView::Template::Error (undefined method `each' for nil:NilClass):
    14:   </thead>
    15: 
    16:   <tbody>
    17:     <% @albums.each do |album| %>
    18:       <tr>
    19:         <td><%= album.name %></td>
    20:         <td><%= album.created_on %></td>
  app/views/users/choose_album_to_add.html.erb:17:in `_app_views_users_choose_album_to_add_html_erb___3017203676622264637_69974786999340'

When I run Album.all on Console I get:

SELECT "albums".* FROM "albums"
 => #<ActiveRecord::Relation [#<Album id: 1, name: "Album1", created_on: "2014-03-17 23:33:00", finishes_on: "2014-03-24 13:16:00", created_at: "2014-03-17 23:33:14", updated_at: "2014-03-24 13:16:32">, #<Album id: 2, name: "Album2", created_on: "2014-03-17 23:33:00", finishes_on: "2014-03-24 13:16:00", created_at: "2014-03-17 23:33:28", updated_at: "2014-03-24 13:16:42">]>

which is my two tuples that I inserted via the Rest methods generated by scaffold.

users_controller.rb

class UsersController < ApplicationController
  before_action :set_user, only: [:show, :edit, :update, :destroy]

  # GET /users
  # GET /users.json
  def index
    @users = User.all
  end

  # GET /users/1
  # GET /users/1.json
  def show
  end

  # GET /users/new
  def new
    @user = User.new
  end

  # GET /users/1/edit
  def edit
  end

  # POST /users
  # POST /users.json
  def create
    @user = User.new(user_params)
    @user.photographer_id = session[:current_photographer_id]

    respond_to do |format|
      if @user.save
        format.html { redirect_to @user, notice: 'Novo usuário cadastrado com sucesso. Um email foi encaminhado a ele contendo as informações de acesso.' }
        format.json { render action: 'show', status: :created, location: @user }
      else
        format.html { render action: 'new' }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /users/1
  # PATCH/PUT /users/1.json
  def update
    respond_to do |format|
      if @user.update(user_params)
        format.html { redirect_to @user, notice: 'Dados atualizados com sucesso' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @user.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /users/1
  # DELETE /users/1.json
  def destroy
    @user.destroy
    respond_to do |format|
      format.html { redirect_to users_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_user
      @user = User.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def user_params
      params.require(:user).permit(:name, :email, :password, :endereco, :telefone, :cpf)
    end

    def choose_album_to_add
       @albums = Album.all
    end

  end
end

Any appointments more? Thanks

Upvotes: 1

Views: 12922

Answers (2)

user740584
user740584

Reputation:

Your method def choose_album_to_add is private - move the definition above the private statement.

Since choose_album_to_add is an action is has to be a public method to be used by the view. I think you already proved the method wasn't being called when you tried to set @albums = 1 and it didn't make any difference.

Upvotes: 5

user2215832
user2215832

Reputation: 1

Is really choose_album_to_add being called when loading the view? (and so, the @album var) As some said in previous comments, if the problem was an empty table it should return an empty array/active_relation.

Another way to have that collection is:

class UsersController < ApplicationController
    helper_method :albums

    private
    def albums
        @albums ||= Album.all
    end
end

Then in your view just call album.each instead of @album.each

Upvotes: 0

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