Finally uploaded File to Google Drive!

Google Drive Upload

Finally I got the file upload to work as expected. I’ve used swagger as described in previous posts, but for some reason it won’t work like that. I will now list the changes I hade to make in order for it to work.

Drive Connection

First I had to change the default adapter for Tesla, Elixir package for http requests. First error I got was with httpc package.

defmodule Drive.Connection do
  @moduledoc """
  Handle Tesla connections for Drive.
  """

  use Tesla

  adapter :hackney

You need to change the the host url to www.googleapis.com/upload/ for it to be able to upload. After you start the server and start up the upload with multipart/form-data, if host stays without upload you will get the wrongUrlUpload error, and it will tell you to re-send the request to supplied url. Just listen to the console and you are closer to Drive upload.

swagger: '2.0'
schemes:
  - https
host: www.googleapis.com/upload/
basePath: drive/v3
info:
  contact:
    name: Google

Open API Yaml

Yaml file used to generate the api client had File model. That was the problem because it interfered with built-in model for File in Java. So I had to change the name to DriveFile. After generating the client stub you will see the Elixir struct create with the name DriveFile.

Facade

To call the drive API I had to create a facade (I will probably rename it to service don’t judge my naming!). Here is the snippet to call the Elixir Drive Client.

# drive_facade.ex

  file = %Drive.Model.DriveFile{
          description: "Hello",
          originalFilename: filename,
          mimeType: "application/octet-stream",
          name: filename
        }
        keyword_list = [{:uploadType, "multipart"}]
        case drive_files_create(driveClient, file, filename, keyword_list) do
          {:ok, resp} ->
            resp |> inspect |> Logger.debug
          {:error, error} ->
            error |> inspect |> Logger.error
        end
    {:error, file_error} ->
      file_error |> inspect |> Logger.error

# drive_files_create function

   %{}
    |> method(:post)
    |> url("/files")
# it is important to get the resource struct first
    |> add_param(:body, :"resource", body)
# after that comes the file
    |> add_param(:file, :"media", file)
    |> add_optional_params(optional_params, opts)
    |> Enum.into([])
    |> (&Connection.request(connection, &1)).()
    |> decode(Drive.Model.DriveFile)

Generation of file part is not dynamic, I added that line directly into the client. What you need to do also is to change %Drive.Model.DriveFile{} to Drive.Model.DriveFile.

That’s all for now! More updates coming soon!