Question

I posted yesterday a question about how to post files through JSON APIs here:

Posting JSON with file content on Ruby / Rails

However I couldn’t really find exactly what I was looking for, so I tried by doing the following:

1) I wrote a rake task to do the upload:

desc "Tests JSON uploads with attached files on multipart formats"
task :picture => :environment do
    file = File.open(Rails.root.join('lib', 'assets', 'photo.jpg'))

    data = {title: "Something", description: "Else", file_content: Base64.encode64(file.read)}.to_json
    req = Net::HTTP::Post.new("/users.json", {"Content-Type" => "application/json", 'Accept' => '*/*'})
    req.body = data

    response = Net::HTTP.new("localhost", "3000").start {|http| http.request(req) }
    puts response.body
  end

And then got this on the controller/model of my rails app, like this:

params[:user] = JSON.parse(request.body.read)

...

class User < ActiveRecord::Base
  ...

    has_attached_file :picture, formats: {medium: "300x300#", thumb: "100#100"}


    def file_content=(c)
      filename = "#{Time.now.to_f.to_s.gsub('.', '_')}.jpg"
      File.open("/tmp/#{filename}", 'wb') {|f| f.write(Base64.decode64(c).strip) }
      self.picture = File.open("/tmp/#{filename}", 'r')
    end
end

So, question is: Am I reinventing the wheel or is this the right way to do it?

BTW: It works, I just need to know if this is a convention for uploading files through json.

Answer 1

JSON is a data serializing format. There is no standard pattern for uploading data or files as data in the serialized object. JSON has expectations that the data fields will be basic objects so you probably want to use Base64 encoding of the file to turn it into a string.

You are free to define your structure however you want, and processing it is your responsibility.