Question

我是铁杆新手。还有网络开发。

很抱歉，如果有些问题看起来很愚蠢。

尝试按照此屏幕投射 - http://emersonlackey.com/screencasts/rails-3-with-paperclip.mov

但停止了问题 - 当我尝试上传图片时，我收到以下错误：

PostsController＃update中的ActiveRecord :: UnknownAttributeError 未知属性：图像

altough post_controller.rb似乎没问题（多次检查 - 它与https://github.com/Emerson/Multiple-File-Uploads-with-Paperclip-and-Rails-3相同）：

当然尝试了googlin，但没有找到任何东西。

是否有人通过本教程并遇到此问题？

Answer 1

问题已修复，_form代码不正确！

我不得不改变：

<%= f.fields_for :assets do |asset| %>

到

<%= f.fields_for :assets do |asset_fields| %>

和

<%= asset.file_field :image %>

到

<%= asset_fields.file_field :asset %>

它有效。

原因很愚蠢，我只是没看到截屏直到最后，因为我停在中间 - 当问题出现时，我全神贯注地搜索解决方案。

初学者错了！

Answer 2

帖子模特：

class Post < ActiveRecord::Base
  attr_accessible :title, :content, :assets_attributes
  has_many :assets
  accepts_nested_attributes_for :assets, :allow_destroy => true
end

资产模型：

class Asset < ActiveRecord::Base
  belongs_to :post
  has_attached_file :asset, :styles => { :large => "640x480", :medium=>"300x300>", 
  :thumb => "100x100>" }
end

邮政控制人：

class PostsController < ApplicationController
  def index
  @posts = Post.all
end

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

def new
 @post = Post.new
 5.times { @post.assets.build }
end


def create
  @post = Post.new(params[:post])
  if @post.save
  redirect_to @post, :notice => "Successfully created post."
else
  render :action => 'new'
 end
end

def edit
  @post = Post.find(params[:id])
  5.times { @post.assets.build }
end

def update
  @post = Post.find(params[:id])
  if @post.update_attributes(params[:post])
  redirect_to @post, :notice  => "Successfully updated post."
else
  render :action => 'edit'
 end
end

def destroy
  @post = Post.find(params[:id])
  @post.destroy
  redirect_to posts_url, :notice => "Successfully destroyed post."
 end
end

_form：

<%= form_for @post, :html => { :multipart => true } do |f| %>
<%= f.error_messages %>
<p>
  <%= f.label :title %><br />
  <%= f.text_field :title %>
</p>
<p>
  <%= f.label :content %><br />
  <%= f.text_area :content %>
</p>

  <%= f.fields_for :assets do |asset| %>

   <% if asset.object.new_record? %>
   <%= asset.file_field :image %>
    <% end %>

 <% end %>

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

模型索引：

<% title "Posts" %>

<p><%= link_to "New Post", new_post_path %></p>

<hr />

<% for post in @posts %>

<div class="post">

    <h2><%= link_to post.title, post%></h2>

<p class="content">         
    <%= post.content.html_safe %>
    <br /><br />
<%= link_to "Edit", edit_post_path(post) %> | <%= link_to "Destroy", post,
     :confirm => 'Are you sure?', :method => :delete %>
    </p>

</div>  

    <% end %>

错误：

Started PUT "/posts/1" for 127.0.0.1 at Tue Sep 20 11:00:52 +0300 2011
 Processing by PostsController#update as HTML
 Parameters: {"commit"=>"Update Post", "post"=>{"title"=>"AAAAA", "content"=>"T
 he enormous success of DropBox clearly shows that there's a huge need for simple
 and fast file sharing.\r\n\r\nOur app will have the following features:\r\n\r\n
 simple user authentication\r\n    upload files and save them in Amazon S3\r\
 n    create folders and organize\r\n    share folders with other users\r\n\r\nTh
 roughout the tutorial, I will point out different ways that we can improve our a
 pp. Along the way, we'll review a variety of concepts, including Rails scaffoldi
 ng and AJAX.", "assets_attributes"=>{"0"=>{"image"=>#<ActionDispatch::Http::Uplo
 adedFile:0x436fda0 @tempfile=#<File:C:/DOCUME~1/emve/LOCALS~1/Temp/RackMultipart
 20110920-8900-zgz1ej-0>, @headers="Content-Disposition: form-data; name=\"post[a
 ssets_attributes][0][image]\"; filename=\"02.jpg\"\r\nContent-Type: image/jpeg\r
 \n", @content_type="image/jpeg", @original_filename="02.jpg">}}}, "authenticity_
 token"=>"WHsbBak0O2xYBFe/h82+4/5aV2VPzHDdXcgb4QYmC4A=", "utf8"=>"Ō£ō", "id"=>"1"
 }
 ←[1m←[35mPost Load (0.0ms)←[0m  SELECT "posts".* FROM "posts" WHERE "posts"."i
 d" = ? LIMIT 1  [["id", "1"]]
 Completed 500 Internal Server Error in 63ms

 ActiveRecord::UnknownAttributeError (unknown attribute: image):
 app/controllers/posts_controller.rb:32:in `update'

 Rendered C:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/actionpack-3.1.0/lib
 /action_dispatch/middleware/templates/rescues/_trace.erb (0.0ms)
 Rendered C:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/actionpack-3.1.0/lib
 /action_dispatch/middleware/templates/rescues/_request_and_response.erb (0.0ms)
 Rendered C:/RailsInstaller/Ruby1.8.7/lib/ruby/gems/1.8/gems/actionpack-3.1.0/lib
 /action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/lay
 out (46.9ms)

带有Paperclip错误的多文件上载

2 个答案: