CODEWITHSUNDEEP
ruby-on-rails
vveare138
vveare138

Reputation: 347

Why association don't working.Undefined method `name' for nil:NilClass

I want to create a polymorphic association between 3 models - User, Post and Comment.But in step when I associate User and Post and added form 'user_id' in view 'posts/index' browser show me an error

undefined method `name' for nil:NilClass

this is my view posts/index.html.haml

- @posts.each do |post|
  = post.title
  = post.body
  = post.user.name

this is my view posts/new.html.haml

= form_for @post do |f|
  = f.text_field :title, placeholder: "title"
  = f.text_field :body, placeholder: "text"
  = f.text_field :user_id, placeholder: "user"
  = f.submit "Send"

this is my controller posts_controller

class PostsController < ApplicationController

  def index
    @posts = Post.all
  end

  def new
    @post = Post.new
  end

  def create
    @post = Post.new(post_params)
    if @post.save
      redirect_to posts_path
    end
  end

  private

  def post_params
    params.require(:post).permit(:title, :body, :user_id)
  end
end

this is my migration create_posts.rb

class CreatePosts < ActiveRecord::Migration
  def change
    create_table :posts do |t|
      t.string :title
      t.text :body
      t.references :user, index: true
      t.timestamps
    end
  end
end

and this is my model Post

class Post < ActiveRecord::Base
  belongs_to :user
end

UPD

2.1.5 :001 > Post.all   Post Load (0.6ms)  SELECT "posts".* FROM "posts"  => #<ActiveRecord::Relation [#<Post id: 1, title: "title", body: "body", user_id: nil, created_at: "2014-12-04 13:27:35", updated_at: "2014-12-04 13:27:35">, #<Post id: 2, title: "title", body: "body", user_id: nil, created_at: "2014-12-04 13:47:36", updated_at: "2014-12-04 13:47:36">, #<Post id: 3, title: "title", body: "body", user_id: 1, created_at: "2014-12-04 13:50:50", updated_at: "2014-12-04 13:50:50">, #<Post id: 4, title: "title", body: "body", user_id: 2, created_at: "2014-12-04 13:57:15", updated_at: "2014-12-04 13:57:15">]> 
2.1.5 :002 >

how fix?

sorry for my bad English

Upvotes: 0

Views: 54

Answers (1)

nathanvda
nathanvda

Reputation: 50057

Does every have post a user_id filled in? I am guessing that is the error not. The simple workaround is to test if there is a user present, before looking for its name. So simply:

= post.user.name if post.user.present?

or, short and sweet:

= post.user.try(:name)

Upvotes: 2

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