rails crop attachment_fu

  def update
@face = Face.find_by_user_id(session[:user_id],:conditions => "parent_id is null" )
    respond_to do |format|
      if @face.update_attributes(params[:face])

#        flash[:notice] = 'Face was successfully updated.'
#        format.html { redirect_to(edit_user_path(@face.user,:web_name => "face")) }
        format.html { redirect_to(:controller => "houses", :action => "show", :id => session[:house_id] ) }
        format.xml  { head k }
      else
        format.html { render :action => "edit" }
        format.xml  { render ml => @face.errors, :status => :unprocessable_entity }
      end
    end
  end



  def update_attributes(att)
#    path = "/home/sunchi/work/demo/swfupload-rails-authentication/public/assets/0000/0050/1521572725770.jpg"
    path = File.expand_path(RAILS_ROOT)+"/public"+self.public_filename(:big)
bash_path = File.expand_path(RAILS_ROOT)+"/public"+self.public_filename
#    scaled_img = Magick::ImageList.new(self.path)
#    orig_img = Magick::ImageList.new(self.path(:original))
    scaled_img = Magick::ImageList.new(path)    # 缩略图
    orig_img = Magick::ImageList.new(bash_path) # 原图
    scale = orig_img.columns.to_f / scaled_img.columns # 按照缩略图于原图缩放比例 进行裁剪

    args = [ att[:x1], att[:y1], att[:width], att[:height] ]
    args = args.collect { |a| a.to_i * scale }

    orig_img.crop!(*args)
#    orig_img.write(self.path(:original))
    orig_img.write(bash_path)

#    self.reprocess!
    self.save!
    super(att)
  end


<div class="fam_h_m">
<div class="head_bg">
<div class="font003 head_line">上传头像</div>
<div style="margin-top: 10px;">
<% form_for @face, :method => :put do |f| -%>
<table cellspacing="0" cellpadding="0" border="0" width="100%">
  <tbody><tr>

    <td width="280">

   <input type="hidden" name="face[x1]" id="x1" /> 
   <input type="hidden" name="face[y1]" id="y1" /> 
   <input type="hidden" name="face[width]" id="width" /> 
   <input type="hidden" name="face[height]" id="height" /> 
<p> 
<div style="width:280px;height:325px;"><%= image_tag(crop_face.public_filename(:big), :style => 'max-height: 325px; max-width: 280px;', :id => "photo")%></div>
  </p> 





<div style="float: left; height: 20px; line-height: 20px;"></div>

</td>
    <td valign="top">
<div class="head_c">
  <p>
   </p><div style="height: 40px; line-height: 40px;"><div style="float: left; margin-top: 10px;"></div> </div>
    <br>

    <div style="width: 100%;"></div>
   
    <p><br>
        <br>
        <br>

        <br>
        <span>预览</span>    

 
    </p><p> <div id="preview" style="margin-left:40px;overflow:hidden;position:relative;  "><span><%= image_tag('yulan.png', :style => "z-index:10001;width:100px;height:100px;")%></span></div></p>
   <br /> 
<div style="margin-top: 30px; margin-left: 40px;">

<!-- <a class="button white" type="submit" id="face_submit" >保存</a>  -->
    <%= f.submit("保存", :class=> "button white" , :style => "background:-moz-linear-gradient(center top , #FFFFFF, #EDEDED) repeat scroll 0 0 transparent;") %>
</div>
</div>
</td>

  </tr>
</tbody></table>
<% end %>
</div>



</div>
</div>



<script type="text/javascript"> 
   function onEndCrop( coords, dimensions ) { 
     $( 'x1' ).value = coords.x1; 
     $( 'y1' ).value = coords.y1; 
      
     $( 'width' ).value = dimensions.width; 
     $( 'height' ).value = dimensions.height; 
   } 
   Event.observe( window, 'load',function() { 
     new Cropper.ImgWithPreview('photo',{ 
       minWidth: 118, 
       minHeight: 115, 
       ratioDim: { x:100, y: 100 }, 
       displayOnInit: true, 
       onEndCrop: onEndCrop, 
       previewWrap: 'preview' 
     }); 
   });
</script>