Rails部分图像渲染

Question

我正在开始加速轨道并遇到一个奇怪的问题。我正在渲染数据库中的一些图像（图像模型附加到另一个模型，植物）。我试图通过局部的方式做一些麻烦。我有show.html.erb

 <fieldset class="fieldset">
      <legend>Images</legend>
      <%=  unless @plant.images.blank? then
                for image in @plant.images
                     debugger 
                     render :partial => 'show_image', :object => image 
                end
           else
                "This plant has no images to display."
           end
      %>
 </fieldset>

部分_show_image.html.erb：

 <div class="image_container">
      <% debugger %>
      <img src="<%= url_for(:action => 'picture', :id => object.id) %>"/> 
      <p class='image_caption'><%= object.comment %></p> 
 </div>

当渲染它时，它只渲染一个“＃”。对于每个图像，而不是实际图像。它似乎只是将对象渲染为字符串，就像我得到的源代码一样：

 <fieldset class="fieldset">
      <legend>Images</legend>
      #<Image:0x242c910>
 </fieldset>

在本地运行调试器时：

 /Users/*****/dev/plantmanager/app/views/plants/show.html.erb:54
 debugger
 (rdb:241) image
 #<Image id: 40, comment: "Test", name: "Ixia.gif", content_type: "image/gif", data: "GIF89a2\0002\000####$\205\233\tI\250\"x\224\b?\206\031d|ju####\v\031###\247\bI\257G\222\232\222\227\263\262...", plant_id: 55, thumbnail: nil> 
 (rdb:221) @plant
 #<Plant id: 55, name: "Test", description: "Test", created_at: "2009-05-07 07:19:44", updated_at: "2009-05-07 07:19:44", planted: "2009-05-07 00:00:00", sprouted: "2009-05-15 00:00:00", plant_type_id: 1, finished: "2009-05-27 00:00:00">
 (rdb:221) @plant.images
 [#<Image id: 40, comment: "Test", name: "Ixia.gif", content_type: "image/gif", data: "GIF89a2\0002\000####$\205\233\tI\250\"x\224\b?\206\031d|ju####\v\031###\247\bI\257G\222\232\222\227\263\262...", plant_id: 55, thumbnail: nil>]
 (rdb:221) continue
 /Users/*****/dev/plantmanager/app/views/plants/_show_image.html.erb:2
 <% debugger %>
 (rdb:221) object
 #<Image id: 40, comment: "Test", name: "Ixia.gif", content_type: "image/gif", data: "GIF89a2\0002\000####$\205\233\tI\250\"x\224\b?\206\031d|ju####\v\031###\247\bI\257G\222\232\222\227\263\262...", plant_id: 55, thumbnail: nil>
 (rdb:221) object.id
 40
 (rdb:221) object.comment
 "Test"
 (rdb:221) continue

以下是我的模型[剪了一下]：

class Plant < ActiveRecord::Base
     has_many :images

     validates_presence_of :name
     validates_presence_of :plant_type_id
     validates_associated :images


     after_update :save_images

     def image_attributes=(image_attributes)
          image_attributes.each do |attributes|
               # TODO: Probably handle validation in the image model?
               if attributes[:id].blank?
                   unless attributes[:uploaded_picture].blank?
                        tmpImg = images.build()
                        tmpImg.uploaded_picture=attributes[:uploaded_picture]
                        tmpImg.comment = attributes[:comment] 
                   end
               else
                   img = images.detect { |i| i.id == attributes[:id].to_i }
                   img.attributes = attributes
                end
           end
      end


      def save_images
           images.each do |i|
                if i.should_destroy?
                     i.destroy
                else
                     i.save(false)
                end
           end 
      end
 end

 class Image < ActiveRecord::Base 
      validates_format_of :content_type, 
                          :with => /^image/, 
                          :message => "--- you can only upload pictures" 

      attr_accessor :should_destroy

      def should_destroy?
           should_destroy.to_i == 1
      end

      def uploaded_picture=(picture_field)
           self.name = base_part_of(picture_field.original_filename) 
           self.content_type = picture_field.content_type.chomp 
           self.data = picture_field.read
           #image = MiniMagick::Image.from_blob self.data
           #self.thumbnail = resize_and_crop(image, 100).to_blob
      end 

      def base_part_of(file_name) 
           File.basename(file_name).gsub(/[^\w._-]/, '') 
      end
 end 

Answer 1

请改为尝试：

<%  unless @plant.images.blank?
                for image in @plant.images
%>
                     <%= render :partial => 'show_image', :object => image %>
                <% end
           else %>
                This plant has no images to display.
           <% end %>

对格式化感到抱歉，但您明白了。

Answer 2

在图像模型中为pic构建方法

class Image < ActiveRecord::Base
   belongs_to :plant
   validates_presence_of :uploaded_picture
   ...
end

在你的植物控制器中

def plant_pic
  img = Image.find(params[:id])      
  # THE NEXT LINE IS THE ONE I THINK YOU ARE MISSING:
  send_data img.uploaded_picture, :filename =>"plant#{img.plant_id}_#{img.id.to_s}+'.jpg', 
                                  :type => 'image/jpeg', 
                                  :disposition => 'inline'
end
...

然后在你的植物视图中：

<fieldset class="fieldset">
  <legend>Images</legend>
  <% if plant.images.blank? -%>
  <p>This plant has no images to display.</p>
  <% else %>
    <%= @plant.images.each do |image| %>
      <div class="img_container"> 
      <img src="<%= url_for(:action => 'plant_pic', :id => image.id) %>"/>
      </div>
    <% end -%>
  <% end -%>
</fieldset>

您可能想要在images控制器中对uploaded_picture二进制字段进行编码/解码（我使用Base64.encode和Base64.decode），但这是另一个问题。

希望能帮到你