Multipart::Post

Adds a streamy multipart form post capability to Net::HTTP. Also supports other methods besides POST.

Features/Problems

Appears to actually work. A good feature to have.
Encapsulates posting of file/binary parts and name/value parameter parts, similar to most browsers' file upload forms.
Provides an UploadIO helper class to prepare IO objects for inclusion in the params hash of the multipart post object.

Installation

gem install multipart-post

or in your Gemfile

gem 'multipart-post'

Usage

require 'net/http/post/multipart'

url = URI.parse('http://www.example.com/upload')
File.open("./image.jpg") 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

To post multiple files or attachments, simply include multiple parameters with UploadIO values:

require 'net/http/post/multipart'

url = URI.parse('http://www.example.com/upload')
req = Net::HTTP::Post::Multipart.new url.path,
  "file1" => UploadIO.new(File.new("./image.jpg"), "image/jpeg", "image.jpg"),
  "file2" => UploadIO.new(File.new("./image2.jpg"), "image/jpeg", "image2.jpg")
res = Net::HTTP.start(url.host, url.port) do |http|
  http.request(req)
end

To post files with other normal, non-file params such as input values, you need to pass hashes to the Multipart.new method.

In Rails 4 for example:

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) #add to Headers
  http.use_ssl = (url.scheme == "https")
  http.request(req)
end

Or in plain ruby:

def params(file)
  params = { "description" => "A nice picture!" }
  params[:datei] = UploadIO.new(file, "image/jpeg", "image.jpg")
  params
end

url = URI.parse('http://www.example.com/upload')
File.open("./image.jpg") do |file|
  req = Net::HTTP::Post::Multipart.new(url.path, params(file))
  res = Net::HTTP.start(url.host, url.port) do |http|
    return http.request(req).body
  end
end

Debugging

You can debug requests and responses (e.g. status codes) for all requests by adding the following code:

http = Net::HTTP.new(uri.host, uri.port)
http.set_debug_output($stdout)

License

Released under the MIT license.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.