用attachment_fu 以及 Rmagick 插件完成上传图片的功能

以前做这块的时候，一起遇到插件安装不上的问题。现在终于解决了。拿出来和大家分享一下。因为要完成上传图片的这个功能，需要用到两个插件:attachment_fu 以及 Rmagick.
所以第一步：安装插件：
sudo gem install rmagick
ruby script/plugin install http://svn.techno-weenie.net/projects/plugins/attachment_fu/
ruby script/plugin install http://sean.treadway.info/svn/plugins/responds_to_parent/
二。用scaffold 创建一个资源
ruby script/generate scaffold photo
*不要忘了修改一下database.yml里面的配置。
三。修改一下migration表：
  

 class CreateAssets < ActiveRecord::Migration  
      def self.up  
        create_table :assets do |t|  
          t.column :filename, :string  
          t.column :content_type, :string  
          t.column :size, :integer  
          t.column :width, :integer  
          t.column :height, :integer  
          t.column :parent_id, :integer  
         t.column :thumbnail, :string  
         t.column :created_at, :datetime  
       end  
     end  
    
     def self.down  
       drop_table :assets  
     end  
  end

 
四。在model里要运用到这个attachment_fu 插件，要写调用语句：

 class Asset < ActiveRecord::Base  
  has_attachment  :storage => :file_system,   
                  :max_size => 1.megabytes,  
            :thumbnails => { :thumb => '80x80>', :tiny => '40x40>' },  
                                    :processor => :Rmagick   
 end

五。在index.html里面调用脚本
"prototype", "effects", "application"
也可以在主页里面用: <%= javascript_include_tag :defaults %>|| <%= javascript_include_tag :all%>
六。修改photo/index.html页面

<% form_for(:asset, :url => assets_path, :html => { :multipart => true }) do |f| %>
        <p>  
        <label for="uploaded_data">Upload a file:</label>
        <%= f.file_field :uploaded_data %>
        </p>
        <p><%= submit_tag "Create" %></p>
      <% end %>
      <iframe id='upload_frame' name="upload_frame" style="width:1px;height:1px;border:0px" src="about:blank"></iframe>  
      <ul id="assets">
        <% @assets.each do |a|%>
          <li id="asset">
          <%= link_to image_tag(a.public_filename(:tiny)) %><br />
          </li>
        <% end %>
      </ul>

七。修改一下photo.controller.rb里面的create action

def create
    @asset = Asset.new(params[:asset])
    respond_to do |format|
      if @asset.save
        flash[:notice] = '图像已经成功上传'
        format.html { redirect_to (@asset) }
        format.xml  { head :created, :location => asset_url(@asset) }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @asset.errors.to_xml }
      end
    end
end

[b]这样，在routes.rb文件里设置一下路由就可以rakd db:migrate 运行了。好了，到浏览器里去看看效果吧。嘿嘿嘿。。

???why no people has problem??

Only minor problems.  It is quite easy to solve them.