"undefined method `errors' for nil:NilClass" when calling on errors method

Question

I am currently teaching myself some RoR and doing the tutorial, but adding some nicer layout and stuff with bootstrap and I am running into a problem which I cant figure out.

I am trying to do the validation part (http://guides.rubyonrails.org/getting_started.html#adding-some-validation), but when I use:

<% @post.errors.any? %> 

I get this message:

undefined method `errors' for nil:NilClass Extracted source (around line #9): <legend><h1>Add Post</h1></legend>  <%= form_for :post, url: posts_path, html: {class: 'form-horizontal'} do |f| %>       <% if @post.errors.any? %>         <div id="errorExplanation"> 

Nothing works and I even copied and pasted the parts from the tutorial.

Here is the code for the view:

<p> </p>  <div class="span6"  <fieldset>     <legend><h1>Add Post</h1></legend>      <%= form_for :post, url: posts_path, html: {class: 'form-horizontal'} do |f| %>           <% if @post.errors.any? %>             <div id="errorExplanation">                  <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2>                  <ul>                     <% @post.errors.full_messages.each do |msg| %>                     <li><%= msg %></li>                     <% end %>                   </ul>             </div>   <% end %>         <div class="control-group">             <%= f.label :title, :class => 'control-label' %>             <div class="controls">                 <%= f.text_field :title, :class => 'span4' %>             </div>         </div>          <div class="control-group">             <%= f.label :content, :class => 'control-label' %>             <div class="controls">                 <%= f.text_area :content, :rows => '7', :class => 'input-block-level' %>             </div>         </div>          <div class="form-actions">             <%= f.submit "Add Post", :class => 'btn btn-success' %>             <%= link_to "Cancel", posts_path, :class => 'btn', :style => 'float:right;' %>         </div>     <% end %> </fieldset>  </div> 

And my posts_controller:

class PostsController < ApplicationController      def new     end      def create         @post = Post.new(params[:post].permit(:title, :content))          if @post.save             redirect_to @post         else             render 'new'         end     end      def show         @post = Post.find(params[:id])     end      def index         @posts = Post.order("created_at desc")     end      private         def post_params             params.require(:post).permit(:title, :content)         end  end 

What am I missing? Thanks in advance!

Answer 1

You need to define @post in your new action too.

def new   @post = Post.new end 

You're getting the NilClass error because @post has no value (it's nil) when you first load the form on the new action.

When you do the render :new in your create action there is no problem because it's using the @post you've defined at the top of create.

Answer 2

Update the create method in posts.controller.rb file with the below piece of code. It worked for me.

def create   @post = Post.new(params[:post].permit(:title, :text))   @post.save   redirect_to @post end