Phoenix Live Upload fetching nil key when updating progress

Phoenix Forum Questions / Help
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1

So I went through Chris McCord’s liveview upload deep dive Phoenix LiveView Uploads Deep Dive - YouTube and I got it uploading to the local static dir(uploading a single image). I think I’m close in getting it uploaded to S3 but I’m encountering an issue right after presigning(by the way I am not using Amazon S3, but Filebase S3 instead):

[error] GenServer #PID<0.520.0> terminating
** (KeyError) key nil not found in: %{"phx-FpNc9C9o6Eh_cQBG" => :photo}
    :erlang.map_get(nil, %{"phx-FpNc9C9o6Eh_cQBG" => :photo})
    (phoenix_live_view 0.15.7) lib/phoenix_live_view/upload.ex:186: Phoenix.LiveView.Upload.get_upload_by_ref!/2
    (phoenix_live_view 0.15.7) lib/phoenix_live_view/upload.ex:127: Phoenix.LiveView.Upload.update_progress/4

here is presign_entry():

  @bucket "secret-secret"

  defp s3_host, do: "//#{@bucket}.s3.filebase.com"
  defp s3_key(entry), do: "#{entry.uuid}.#{ext(entry)}"


  defp presign_entry(entry, socket) do
    uploads = socket.assigns.uploads
    key = s3_key(entry)

    IO.inspect(key, label: "key s3_key")

    config = %{
      scheme: "https://",
      host: "s3.filebase.com",
      region: "us-east-1",
      access_key_id: "secret", 
      secret_access_key: "secret"
    }

    {:ok, fields} =
      SimpleS3Upload.sign_form_upload(config, @bucket,
        key: key,
        content_type: entry.client_type,
        max_file_size: uploads.photo.max_file_size,
        expires_in: :timer.hours(1)
      )

    IO.inspect(fields, label: "fields")
    meta = %{uploader: "S3", key: key, url: s3_host(), fields: fields}
    IO.inspect(meta, label: "meta")
    {:ok, meta, socket}

  end

my log shows the presign succeed right before the getting of the nil key:

key s3_key: "b60bd61d-c4a9-41d3-8e56-8550d504c222.jpg"
fields: %{
  "acl" => "public-read",
  "content-type" => "image/jpeg",
  "key" => "b60bd61d-c4a9-41d3-8e56-8550d504c222.jpg",
  "policy" => "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",
  "x-amz-algorithm" => "AWS4-HMAC-SHA256",
  "x-amz-credential" => "1CBCC95D0A4B4E7D09A3/20210720/us-east-1/s3/aws4_request",
  "x-amz-date" => "20210720T025511Z",
  "x-amz-server-side-encryption" => "AES256",
  "x-amz-signature" => "c1a79a82adef92949bef63302c667995c596e6a79b3de3620530991726851762"
}
meta: %{
  fields: %{
    "acl" => "public-read",
    "content-type" => "image/jpeg",
    "key" => "b60bd61d-c4a9-41d3-8e56-8550d504c222.jpg",
    "policy" => "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",
    "x-amz-algorithm" => "AWS4-HMAC-SHA256",
    "x-amz-credential" => "1CBCC95D0A4B4E7D09A3/20210720/us-east-1/s3/aws4_request",
    "x-amz-date" => "20210720T025511Z",
    "x-amz-server-side-encryption" => "AES256",
    "x-amz-signature" => "c1a79a82adef92949bef63302c667995c596e6a79b3de3620530991726851762"
  },
  key: "b60bd61d-c4a9-41d3-8e56-8550d504c222.jpg",
  uploader: "S3",
  url: "//secret-secret.s3.filebase.com"
}

so I’m not sure why this would fail when the upload to the local static dir would succeed? program flow does not even seem to hit defp save_sticker(socket, :new, sticker_params) do I’ve created a gist including log trace of the entire form_component.ex:

Phoenix 1.5.9, liveview 0.15

Any ideas would be greatly appreciated…

2

Hi, I was having the same error as you.
And I guess I found the solution (at least for me).

The problem was with xhr.onload in uploaders.js

Mine was like this:
xhr.onload = () => xhr.status === 204 || entry.error()

So the function would call on entry.error() everytime, causing the page to break and reloading liveview.
And by reloading liveview, the upload ref id (i.e phx-FpR3OwUkZWgm-g-m) changes, so Phoenix was constantly loosing track of my uploads, giving me that ** (KeyError) key nil not found in: %{"phx-FpR3OwUkZWgm-g-m" => :photo}

So I changed the xhr.onload to:
xhr.onload = () => ((xhr.status === 204 || 200) ? entry.progress(100) : entry.error())
And it stopped giving me the KeyError on Phoenix

3

hey thanks for the suggestion. So I’m still getting the issue, same error as before. Not sure what it could possibly be, I even attempted with an s3.amazonaws.com bucket, thinking it might be the simple_s3_uploader.ex Thanks anyway though.

4

Not seeing this issue anymore after upgrading to phoenix 1.6 and liveview 0.16.4.

5
6

I too had this issue and updating to 0.16.4 solved it for me. Anyone else having this issue, also check your console in the browser for any pre-sign errors if you’re uploading to s3