當fileupload form_tag rails

Question

時遇到麻煩，當我通過POST查詢API使用form_tag for fileupload。 當我用：

= form_tag("http://myapi.com/api/images/user/#{@user_id}", multipart: true) do 
= file_field_tag 'upload' 
= submit_tag 'Upload avatar' 

我沒有麻煩。但是當我嘗試使用update_avatar的動作時，我遇到了麻煩。

= form_tag({:action => 'upload_avatar'}, multipart: true) do 
= file_field_tag 'upload' 
= submit_tag 'Upload avatar' 

update_avatar動作代碼：

def upload_avatar 
    @user_id = params[:id] 
    @post_params = {'upload' => params[:upload]} 
    response, data = Net::HTTP.post_form(URI.parse("http://myapi.com/api/images/user/#{@user_id}"), @post_params) 
    redirect_to users_path 
end 

響應爲：

#<Net::HTTPInternalServerError:0x007f331486f4e0> 

數據是：無

Answer 1

Here 3種方式上傳文件

require "net/http" 
require "uri" 

# Token used to terminate the file in the post body. Make sure it is not 
# present in the file you're uploading. 
BOUNDARY = "AaB03x" 

uri = URI.parse("http://something.com/uploads") 
file = "/path/to/your/testfile.txt" 

post_body = [] 
post_body << "--#{BOUNDARY}\r\n" 
post_body << "Content-Disposition: form-data; name=\"datafile\"; filename=\"#{File.basename(file)}\"\r\n" 
post_body << "Content-Type: text/plain\r\n" 
post_body << "\r\n" 
post_body << File.read(file) 
post_body << "\r\n--#{BOUNDARY}--\r\n" 

http = Net::HTTP.new(uri.host, uri.port) 
request = Net::HTTP::Post.new(uri.request_uri) 
request.body = post_body.join 
request["Content-Type"] = "multipart/form-data, boundary=#{BOUNDARY}" 

http.request(request) 

# Alternative method, using Nick Sieger's multipart-post gem 
require "rubygems" 
require "net/http/post/multipart" 

reqest = Net::HTTP::Post::Multipart.new uri.request_uri, "file" => UploadIO.new(file, "application/octet-stream") 
http = Net::HTTP.new(uri.host, uri.port) 
http.request(request) 

# Another alternative, using Rack 1.3 + 
require 'rack' 
uri  = URI.parse("http://something.com/uploads") 
http = Net::HTTP.new(uri.host, uri.port) 
request = Net::HTTP::Post.new(uri.request_uri) 

request.body = Rack::Multipart::Generator.new(
    "form_text_field" => "random text here", 
    "file"   => Rack::Multipart::UploadedFile.new(path_to_file, file_mime_type) 
).dump 
request.content_type = "multipart/form-data, boundary=#{Rack::Multipart::MULTIPART_BOUNDARY}" 

http.request(request) 

http.start do |connection| 
    response = retrying_request(connection, request) 
end