我正在使用官方网站上的入门教程学习 ruby on rails。http://guides.rubyonrails.org/getting_started.html
我唯一改变的是post url映射指向/post/friendly-url而不是/post/id
在我尝试向帖子添加评论之前，一切都很顺利，我收到以下错误。
CommentsController#create 中的 NoMethodError
undefined method `comments' for nil:NilClass
app/controllers/comments_controller.rb:7:in `create'
这是我的代码。
/app/controllers/comments_controller.rb
class CommentsController < ApplicationController
def create
@post = Post.find_by_friendly(params[:id])
@comment = @post.comments.create(params[:comment])
redirect_to post_path(@post)
end
def destroy
@post = Post.find_by_friendly(params[:id])
@comment = @post.comments.find(params[:id])
@comment.destroy
redirect_to post_path(@post)
end
end
/app/models/comment.rb
class Comment < ActiveRecord::Base
belongs_to :post
attr_accessible :body, :commenter
validates :body, :presence => true
validates :commenter, :presence => true
end
/app/views/comments/_form.html.erb
<%= form_for([@post, @post.comments.build]) do |f| %>
<%= f.label :commenter, "Your Name:" %>
<%= f.text_field :commenter, :placeholder => "Your Name..." %>
<span class="help-block">What would you like to be called.</span><br/>
<%= f.label :body, "Your Comment:" %>
<%= f.text_area :body, :size => "60x12", :placeholder => "Your Comment..." %>
<span class="help-block">What's on your mind?</span><br/>
<%= f.submit %>
<% end %>
/app/views/posts/_form.html.erb
<% @post.tags.build %>
<%= form_for(@post) do |post_form| %>
<legend>Post Form</legend>
<% if @post.errors.any? %>
<div id="error_explanation">
<h2 class="text-error"><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2>
<ul>
<% @post.errors.full_messages.each do |msg| %>
<li class="text-error"><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= post_form.label :name, "Post Name:" %>
<%= post_form.text_field :name, :placeholder => "Post Name..." %>
<span class="help-block">The title of the article.</span><br/>
<%= post_form.label :friendly, "Friendly URL:" %>
<%= post_form.text_field :friendly, :placeholder => "Friendly URL..." %>
<span class="help-block">SEO friendly URL displayed as /posts/post-name.</span><br/>
<%= post_form.label :content, "Post Content:" %>
<%= post_form.text_area :content, :size => "60x12", :placeholder => "Main Content..." %>
<span class="help-block">HTML enabled article content.</span><br/>
<%= post_form.label :excerpt, "Post Excerpt:" %>
<%= post_form.text_area :excerpt, :placeholder => "Post Excerpt..." %>
<span class="help-block">Description of post for index page. No HTML.</span><br/>
<h2>Tags</h2>
<%= render :partial => 'tags/form',
:locals => {:form => post_form} %><br/>
<%= post_form.submit %>
<% end %>
/config/routes.rb
Nullpulse::Application.routes.draw do
resources :posts do
resources :comments
end
root :to => "home#index"
end
/apps/models/post.rb
class Post < ActiveRecord::Base
attr_accessible :content, :friendly, :name, :excerpt, :tags_attributes
validates :name, :presence => true
validates :content, :presence => true
validates :friendly, :presence => true
validates :excerpt, :presence => true
validates_format_of :friendly, :with => /^[^ ]+$/
has_many :comments, :dependent => :destroy
has_many :tags
accepts_nested_attributes_for :tags, :allow_destroy => :true,
:reject_if => proc { |attrs| attrs.all? { |k, v| v.blank? } }
def to_param
friendly
end
end
对不起，如果信息太多，如果我遗漏了什么，请告诉我。我一直在尝试一切，但找不到问题。提前致谢。