Creating a Friend While On Their Profile Page-Collection of common programming errors

2 years ago

admin

5 minutes

I want a User(x) to be able to add another User(y) as a friend while User(x) is on User(y’s) Profile Page. I set up a has_many_through and everything works except that I can only add a friend from the User Index View. Thank you in advance…The code is below:

Also:

I wanted to place the “friend” link on the view/profile/show.html.erb. When I added @users = User.all to the existing profiles_controller.rb I received the error – undefined method friendships' for nil:NilClass. When I replaced @user = User.find(params[:id]) with @users = User.all I received the error - NoMethodError in Profiles#show... undefined methodinverse_friends’ for nil:NilClass

The Code that works in UserIndexView but not ProfileShowView:

% for user in @users %>
    
    

       
       user), :method => :post%>

The following error occurs:

    NoMethodError in Profiles#show
    Showing /Users/mgoff1/LOAP_1.2.2/app/views/profiles/show.html.erb where line #13 raised:
undefined method `each' for nil:NilClass
Extracted source (around line #13):
10: 
11: 
12: 
13:   
14:       
15:         

16:            
    . . .

app/views/profiles/show.html.erb:    13:in`_app_views_profiles_show_html_erb___2905846706508390660_2152968520'
app/controllers/profiles_controller.rb:19:in `show'

The code to the rest is below.

friendship.rb

class Friendship < ActiveRecord::Base
attr_accessible :create, :destroy, :friend_id, :user_id

 belongs_to :user
 belongs_to :friend, :class_name => "User"
end

user.rb

    class User < ActiveRecord::Base
  has_many :friendships
  has_many :friends, :through => :friendships
  has_many :inverse_friendships, :class_name => "Friendship", :foreign_key =>   "friend_id"
  has_many :inverse_friends, :through => :inverse_friendships, :source => :user

  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me,    :profile_attributes
  # attr_accessible :title, :body



  has_one :profile
  accepts_nested_attributes_for :profile

  before_save do | user |
  user.profile = Profile.new unless user.profile
 end
end

friendships_controller.rb

class FriendshipsController < ApplicationController
  def create
    @friendship = current_user.friendships.build(:friend_id => params[:friend_id])
    if @friendship.save
      flash[:notice] = "Added friend."
      redirect_to current_user.profile
    else
      flash[:error] = "Unable to add friend."
      redirect_to root_url
    end
   end

  def destroy
    @friendship = current_user.friendships.find(params[:id])
    @friendship.destroy
    flash[:notice] = "Removed friendship."
    redirect_to current_user.profile
  end
 end

users_controller.rb

class UsersController < ApplicationController
  def show
    @user = User.find(params[:id])
  end

  def index
    @users = User.all
  end
end

profiles_controller.rb

class ProfilesController < ApplicationController
  # GET /profiles
  # GET /profiles.json
  def index
    @profiles = Profile.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @profiles }
    end
  end

  # GET /profiles/1
  # GET /profiles/1.json
  def show
    @user = User.find(params[:id])
    @profile = Profile.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @profile }
    end
  end

  # GET /profiles/new
  # GET /profiles/new.json
  def new
    @profile = Profile.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @profile }
    end
  end

  # GET /profiles/1/edit
  def edit
    @user = User.find(params[:id])
    @profile = Profile.find(params[:id])
  end

  # POST /profiles
  # POST /profiles.json
  def create
    @profile = Profile.new(params[:profile])

    respond_to do |format|
      if @profile.save
         format.html { redirect_to @profile, notice: 'Profile was successfully created.' }
         format.json { render json: @profile, status: :created, location: @profile }
      else
        format.html { render action: "new" }
         format.json { render json: @profile.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /profiles/1
  # PUT /profiles/1.json
  def update
    @profile = Profile.find(params[:id])

    respond_to do |format|
      if @profile.update_attributes(params[:profile])
        format.html { redirect_to @profile, notice: 'Profile was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @profile.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /profiles/1
  # DELETE /profiles/1.json
  def destroy
    @profile = Profile.find(params[:id])
    @profile.destroy

    respond_to do |format|
      format.html { redirect_to profiles_url }
      format.json { head :no_content }
    end
  end
 end

routes.rb

BaseApp::Application.routes.draw do


  resources :friendships

  resources :profiles

  #get "users/show"

  devise_for :users, :controllers => { :registrations => "registrations" }
  resources :users

  match '/show', to: 'profile#show'




  match '/signup',  to: 'users#new'

  root to: 'static_pages#home'

  match '/', to: 'static_pages#home'

  . . .

You aren’t setting @users in ProfilesController#show.

for object in collection just calls collection.each do |object|, which is why you’re getting undefined method 'each' for NilClass (and also why it’s generally discouraged to use that syntax, as it creates confusing errors like this one).

profiles_controller.rb
```
def show
  @users = User.all
  #...
end
```
Anytime you try to call methods with no actual object you’ll get the ‘method undefined’.

It means that the method IS defined – but you have a ‘nil’ and are trying to call it on that and that method doesn’t exists for the ‘nil’ object.

Please check your actual users table. You’ll need users to work with. Please verify that you have some.

If necessary you can create users (at the script/rails console) with

User.new(:name=>'fred', :password =>'pword', :password_confirmation => 'pword' )

You can also place this in your db/seeds.db file so you can run rake db:seed the first time you set the application up on a new machine.

Originally posted 2013-11-09 22:47:04.