设置多态有很多麻烦。我有工作正常的评论,但应该工作完全相同的链接在链接#index 中有 NameError。如果我尝试 forum_posts/1/comments 一切都很好,但没有 forum_posts/1/links。
我正在关注 railscast 教程http://railscasts.com/episodes/154-polymorphic-association?view=asciicast
感谢帮助。
错误
链接中的名称错误#index
未初始化的常量 ForumPost::Link 提取的源代码(第 4 行附近):
1: <h1>Links</h1>
2:
3: <ul id="links">
4: <% @links.each do |link| %>
5: <li><%= link.display_name %></li>
6: <% end %>
7: </ul>
路线
resources :forum_posts do
resources :comments
resources :links
end
楷模
*模型/forum_posts.rb*
class ForumPost < ActiveRecord::Base
attr_accessible :content, :display_name, :section, :user_id
has_many :comments, :as => :commentable
has_many :links, :as => :linkable
end
模型/评论.rb
class Comment < ActiveRecord::Base
attr_accessible :commentable_id, :commentable_type, :content, :user_id
belongs_to :commentable, :polymorphic => true
end
模型/评论.rb
class Links < ActiveRecord::Base
attr_accessible :description, :display_name, :inamge, :linkable_id, :linkable_type, :user_id
belongs_to :linkable, :polymorphic => true
end
控制器
*控制器/comments_controller.rb*
class CommentsController < ApplicationController
def find_commentable
params.each do |name, value|
if name =~ /(.+)_id$/
return $1.classify.constantize.find(value)
end
end
nil
end
def index
@commentable = find_commentable
@comments = @commentable.comments
end
def create
@commentable = find_commentable
@comment = @commentable.comments.build(params[:comment])
if @comment.save
flash[:notice] = "Successfully saved comment."
redirect_to :id => nil
else
render :action => 'new'
end
end
end
*控制器/links_controller.rb*
class LinksController < ApplicationController
def find_linkable
params.each do |name, value|
if name =~ /(.+)_id$/
return $1.classify.constantize.find(value)
end
end
nil
end
def index
@linkable = find_linkable
@links = @linkable.links
end
def create
@linkable = find_linkable
@link = @linkable.links.build(params[:link])
if @link.save
flash[:notice] = "Successfully saved link."
redirect_to :id => nil
else
render :action => 'new'
end
end
end
意见
意见/评论/index.html.erb
<h1>Comments</h1>
<ul id="comments">
<% @comments.each do |comment| %>
<li><%= comment.content %></li>
<% end %>
</ul>
<h2>New Comment</h2>
<%= form_for [@commentable, Comment.new()] do |form| %>
<%= form.label :content %><br/>
<%= form.text_area :content, :rows => 5 %><br/>
<%= form.submit "Add comment" %>
<% end %>
意见/链接/index.html.erb
<h1>Links</h1>
<ul id="links">
<% @links.each do |link| %>
<li><%= link.display_name %></li>
<% end %>
</ul>
<h2>New Link</h2>
<%= form_for [@linkable, Link.new()] do |form| %>
<%= form.label :display_name %><br/>
<%= form.text_area :display_name %><br/>
<%= form.submit "Add link" %>
<% end %>