Rails回形针URL上传问题以及如何使其干燥

问题描述

|| 我正在尝试使用回形针创建URL上传。 我遵循了该指南：http://trevorturk.com/2008/12/11/easy-upload-via-url-with-paperclip/ 问题是当我使用image_url字段时，什么都没有上传。我知道我的代码不是很枯燥，所以如果有人有一些重写代码的技巧，那会很好。 我有2个附加图像，因此有2个图像URL。 我的konkurrancers表：

photo_file_name        varchar(255) 
photo_content_type      varchar(255) 
photo_file_size         int(11)
photo_updated_at        datetime    
photo2_file_name        varchar(255)
photo2_content_type     varchar(255) 
photo2_file_size        int(11)
photo2_updated_at       datetime
image_remote_url        varchar(255)
image_remote_url_2      varchar(255)

我的konkurrancer模型：

class Konkurrancer < ActiveRecord::Base
has_attached_file :photo,:url  => \"/public/images/billeder/photo/:id/:basename.:extension\",:path => \":rails_root/public/images/billeder/photo/:id/:basename.:extension\"
has_attached_file :photo2,:url  => \"/public/images/billeder/photo2/:id/:basename.:extension\",:path => \":rails_root/public/images/billeder/photo2/:id/:basename.:extension\"

 before_validation :download_remote_image,:if => :image_url_provided?
  before_validation :download_remote_image_2,:if => :image_url_2_provided?
  validates_presence_of :image_remote_url,:if => :image_url_provided?,:message => \'is invalid or inaccessible\'
  validates_presence_of :image_remote_url_2,:if => :image_url_2_provided?,:message => \'is invalid or inaccessible\'

private

  def image_url_provided?
    !self.image_url.blank?
  end

  def image_url_2_provided?
    !self.image_url_2.blank?
  end

  def download_remote_image
    self.photo = do_download_remote_image
    self.image_remote_url = image_url
  end

    def download_remote_image_2
    self.photo2 = do_download_remote_image_2
    self.image_remote_url_2 = image_url_2
  end

  def do_download_remote_image
    io = open(URI.parse(image_url))
    def io.original_filename; base_uri.path.split(\'/\').last; end
    io.original_filename.blank? ? nil : io
  rescue # catch url errors with validations instead of exceptions (Errno::ENOENT,OpenURI::HTTPError,etc...)
  end
  def do_download_remote_image_2
    io = open(URI.parse(image_url_2))
    def io.original_filename; base_uri.path.split(\'/\').last; end
    io.original_filename.blank? ? nil : io
  rescue # catch url errors with validations instead of exceptions (Errno::ENOENT,etc...)
  end
end

我的控制器创建动作：

  def create
    @konkurrancer = Konkurrancer.new(params[:konkurrancer])

    respond_to do |format|
      if @konkurrancer.save
        format.html { redirect_to(:admin_konkurrancers,:notice => \'Konkurrancer was successfully created.\') }
        format.xml  { render :xml => :admin_konkurrancers,:status => :created,:location => @konkurrancer }
      else
        format.html { render :action => \"new\" }
        format.xml  { render :xml => @konkurrancer.errors,:status => :unprocessable_entity }
      end
    end
  end

我的表格：

<%= simple_form_for [:admin,@konkurrancer],:html => { :multipart => true } do |f| %>
    <%= f.label :upload_125x125 %>
    <%= f.file_field :photo,:label => \'125x125\',:style => \'width:250;\' %>
    <%= f.input :image_url_2,:label => \'URL 125x125\',:style => \'width:250;\' %>
    <%= f.label :upload_460x60 %>
    <%= f.file_field :photo2,:label => \'460x58\',:style => \'width:250;\' %>
    <%= f.button :submit,:value => \'Create konkurrence\' %>
<% end %>

    

解决方法

        在最新版本的回形针中（合并了拉纸请求，但我不确定该版本）回形针> 3.1.3（也许即将发布3.2；也许是3.1.4），这变得更加容易。

self.photo = URI.parse(\"http://something.com/blah/image.png\")

上面应该注意下载/临时文件内容/文件名和文件内容类型。 请享用！ :)     ,        要解决重复模型的问题，您需要为照片创建一个单独的类，该类存储konkurrence的外键：

class Photo < ActiveRecord::Base
    has_attached_file ...
    belongs_to :konkurrence
    ...
end

class Konkurrence < ActiveRecord::Base
    has_many :photos,:dependent => :destroy
    accepts_nested_attributes_for :photos,:allow_destroy => true
    ...
end

另外，我认为您正在尝试从URL下载远程图像，然后将其保存到Paperclip中。使用open-uri（我相信您已经是），您可以这样进行：

# open a tempfile using the last 14 chars of the filename
t = Tempfile.new(image_url.parameterize.slice(-14,14))
t.write(open(image_url).read)
t.flush
t # return the File. You can then set the paperclip attribute to this File,eg,self.photo = t

这会将您的URL保存为临时文件，然后您可以将其传递给Paperclip进行常规处理。