Question

我想使用Net::HTTP::multipart从Heroku应用程序向Facebook发布新照片。

我有以下JSON对象：

{"message"=>"My message", "image"=>#<ActionDispatch::Http::UploadedFile:0x00000004242490 @original_filename="neEZYMAnBI.jpg", @content_type="application/octet-stream", @headers="Content-Disposition: form-data; name=\"image\"; filename=\"/home/user/public/direct/fb_images/neEZYMAnBI.jpg\"\r\nContent-Type: application/octet-stream\r\n", @tempfile=#<File:/app/tmp/RackMultipart20110818-1-18qnwtj>>, "method"=>"post", "access_token"=>"my_access_token", "format"=>"json"}

我试图使用：

require 'net/http/post/multipart'

url = URI.parse('https://graph.facebook.com/me/photos?access_token=#{params[:access_token]}')
File.open(params[@tempfile]) do |jpg|
  req = Net::HTTP::Post::Multipart.new url.path,
    "file" => UploadIO.new(jpg, "image/jpeg", "image.jpg")
  res = Net::HTTP.start(url.host, url.port) do |http|
    http.request(req)
  end
end

可是：

不发送数据。
我找不到如何将params [：message]与文件一起发送，以便为图像添加标题。

有人可以建议解决方案吗？

由于

Answer 1

您已经可以使用File

访问TempFile个实例（以及params[:image].tempfile个实例）

删除所有File.open内容，然后使用以下内容构建UploadIO：

UploadIO.new(params[:image].tempfile, ...)

Answer 2

如何使用该文件发送params [：message]以获取图片标题？

在Rails 4中，发布带有其他正常参数（如输入值）的文件应该如下所示

def model_params
  require_params = params.require(:model).permit(:param_one, :param_two, :param_three, :avatar)
  require_params[:avatar] = model_params[:avatar].present? ? UploadIO.new(model_params[:avatar].tempfile,  model_params[:avatar].content_type, model_params[:avatar].original_filename) : nil
  require_params
end

require 'net/http/post/multipart'

url = URI.parse('http://www.example.com/upload')
Net::HTTP.start(url.host, url.port) do |http|
  req = Net::HTTP::Post::Multipart.new(url, model_params)
  key = "authorization_key"
  req.add_field("Authorization", key)
  http.use_ssl = (url.scheme == "https")
  http.request(req)
end

在你的情况下，只是

req = Net::HTTP::Post::Multipart.new(url.path, 
      { 
        "file" => UploadIO.new(params[:image].tempfile,  
                               params[:image].content_type,
                               params[:image].original_filename),
        "message" => params[:message]
      })

更简单

params[:image] = UploadIO.new(params[:image].tempfile,  
                              params[:image].content_type,
                              params[:image].original_filename)
req = Net::HTTP::Post::Multipart.new(url.path, params)

https://github.com/Feuda/multipart-post/tree/patch-1

Rails：如何通过HTTP将文件作为multipart / form-data发布到Facebook？

2 个答案: