change.md

<% if @post.errors.any? %>

<%= pluralize(@post.errors.count, "error") %> stopped this post from saving

<% @post.errors.full_messages.each do |msg| %>
• <%= msg %>
<% end %>

<% end %>

NoMethodError.md

Section 10 - Project 2 #39

• Given that I am at http://localhost:3000/posts/new
• When the server is running
• Then I get the error "NoMethodError in Posts#new"

Solution: Restart the server

I worked on it the next day. I checked the code. Suddenly it was working. It may have been a white spave issue.

NoMethodError in Posts#new

undefined method errors for nil:NilClass

Extracted source (around line #5):
3
4  <%= form_for :post, url: posts_path do |f| %>
5    <% if @post.errors.any? %>
6      <div id="errors">
7        <h2><%= pluralize(@post.errors.count, "error") %> stopped this post from saving</h2>
8        <ul>

---

• I know that this means that the Post is not being seen, so the methods errors.any? cannot be called on it.
• I'm not sure why @post is not there.

---

I ran the rails console to make sure that @post is being created

2.3.0 :018 >   @post = Post.new
 => #<Post id: nil, title: nil, body: nil, created_at: nil, updated_at: nil> 

2.3.0 :019 > @post.title="hi"
 => "hi"

2.3.0 :020 > @post.save
   (1.4ms)  BEGIN
   (1.1ms)  ROLLBACK
 => false

2.3.0 :021 > @post.errors
 => #<ActiveModel::Errors:0x00000002f12dc0 @base=#<Post id: nil, title: "hi", body: nil, created_at: nil, updated_at: nil>, @messages={:title=>["is too short (minimum is 5 characters)"], :body=>["can't be blank"]}, @details={:title=>[{:error=>:too_short, :count=>5}], :body=>[{:error=>:blank}]}>

2.3.0 :022 > @post.errors.any?
 => true

2.3.0 :023 > @post.errors.count
 => 2 

2.3.0 :024 > @post.errors.full_messages
 => ["Title is too short (minimum is 5 characters)", "Body can't be blank"] 

My Code

===

app/controllers/post_controllers.rb

class PostsController < ApplicationController
  def index
    @posts = Post.all.order("created_at DESC")
  end

  def new
    @post = Post.new
  end

  def show
    @post = Post.find(params[:id])
  end

  def create
    @post = Post.new(post_params)
    if @post.save
      redirect_to @post
    else
      render 'new'
    end
  end

  private

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

===

app/view/posts/new.html.erb

<div id="page_wrapper">
  <h1 class="title">Add something</h1>

  <%= form_for :post, url: posts_path do |f| %>
    <% if @post.errors.any? %>
      <div id="errors">
        <h2><%= pluralize(@post.errors.count, "error") %> stopped this post from saving</h2>
        <ul>
          <% @post.errors.full_messages.each do |msg| %>
            <li><%= msg %></li>
          <% end %>
        </ul>
      </div>
    <% end %>
    <p>
      <%= f.label :title %><br/>
      <%= f.text_field :title %>
    </p>

    <p>
      <%= f.label :body %><br/>
      <%= f.text_area :body %>
    </p>

    <p>
      <%= f.submit %><br/>
    </p>
  <% end %>
</div>

===

app/models/post.rb

class Post < ApplicationRecord
  validates :title, presence: true, length: { minimum: 5 }
  validates :body, presence: true
end

---

Without this block of code http://localhost:3000/posts/new works fine

app/view/posts/new.html.erb

    <% if @post.errors.any? %>
      <div id="errors">
        <h2><%= pluralize(@post.errors.count, "error") %> stopped this post from saving</h2>
        <ul>
          <% @post.errors.full_messages.each do |msg| %>
            <li><%= msg %></li>
          <% end %>
        </ul>
      </div>
    <% end %>