uploading file with grape and paperclip

Question

I'm working on a REST API, trying to upload a picture of user with:

• grape micro-framework
• paperclip gem but it's not working, showing this error
• rails version is 3.2.8

No handler found for #<Hashie::Mash filename="user.png" head="Content-Disposition: form-data; name=\"picture\"; filename=\"user.png\"\r\nContent-Type: image/png\r\n" name="picture" tempfile=#<File:/var/folders/7g/b_rgx2c909vf8dpk2v00r7r80000gn/T/RackMultipart20121228-52105-43ered> type="image/png">

I tried testing paperclip with a controller and it worked but when I try to upload via grape api its not working my post header is multipart/form-data

My code for the upload is this

 user = User.find(20) 
 user.picture = params[:picture] 
 user.save! 

So if it is not possible to upload files via grape is there any alternative way to upload files via REST api?

Answer 1

@ahmad-sherif solution works but you loose original_filename (and extension) and that can provide probems with preprocessors and validators. You can use ActionDispatch::Http::UploadedFile like this:

  desc "Update image"
  params do
    requires :id, :type => String, :desc => "ID."
    requires :image, :type => Rack::Multipart::UploadedFile, :desc => "Image file."
  end
  post :image do
    new_file = ActionDispatch::Http::UploadedFile.new(params[:image])
    object = SomeObject.find(params[:id])
    object.image = new_file
    object.save
  end

Answer 2

Maybe a more consistent way to do this would be to define paperclip adapter for Hashie::Mash

module Paperclip
  class HashieMashUploadedFileAdapter < AbstractAdapter

    def initialize(target)
      @tempfile, @content_type, @size = target.tempfile, target.type, target.tempfile.size
      self.original_filename = target.filename
    end

  end
end

Paperclip.io_adapters.register Paperclip::HashieMashUploadedFileAdapter do |target|
  target.is_a? Hashie::Mash
end

and use it "transparently"

 user = User.find(20) 
 user.picture = params[:picture] 
 user.save! 

added to wiki - https://github.com/intridea/grape/wiki/Uploaded-file-and-paperclip

Answer 3

You can pass the File object you got in params[:picture][:tempfile] as Paperclip got an adapter for File objects, like this

user.picture = params[:picture][:tempfile]
user.picture_file_name = params[:picture][:filename] # Preserve the original file name