我刚刚安装了Paperclip插件,但是我收到了以下错误信息,我不确定原因是什么:
NoMethodError (undefined method `has_attached_file' for #<Class:0x10338acd0>):
/Users/bgadoci/.gem/ruby/1.8/gems/will_paginate-2.3.12/lib/will_paginate/finder.rb:170:in `method_missing'
app/models/post.rb:2
app/controllers/posts_controller.rb:50:in `show'
这段代码引用了will_paginate gem。据我所知,可能是我的PostsController#index
有问题,或者之前尝试安装gem而不是插件时出现了问题,在这种情况下,我应该通过某种方式在/config/environments.rb
文件中解决问题。
我原本认为之前安装的gem不会有影响,因为我是在一个旧版的网站上安装的,然后将其删除并安装了插件。在当前版本的网站中,经过迁移后已经更新了带有Paperclip列的表。以下是我的代码:
PostsConroller#show
:
def show
@post = Post.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.xml { render :xml => @post }
end
end
帖子
模型:
class Post < ActiveRecord::Base
has_attached_file :photo
validates_presence_of :body, :title
has_many :comments, :dependent => :destroy
has_many :tags, :dependent => :destroy
has_many :votes, :dependent => :destroy
belongs_to :user
after_create :self_vote
def self_vote
# I am assuming you have a user_id field in `posts` and `votes` table.
self.votes.create(:user => self.user)
end
cattr_reader :per_page
@@per_page = 10
end
/views/posts/new.html.erb
:
<h1>New post</h1>
<%= link_to 'Back', posts_path %>
<% form_for(@post, :html => { :multipart => true}) do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :title %><br />
<%= f.text_field :title %>
</p>
<p>
<%= f.label :body %><br />
<%= f.text_area :body %>
</p>
<p>
<%= f.file_field :photo %>
</p>
<p>
<%= f.submit 'Create' %>
</p>
<% end %>