Rails Turbo Broadcast Update to Partial

How to send page updates with Hotwire using a specific partial.

The Views

When broadcasting, the rendering engine expects a partial to render. This is nice anyway because you can use the partial in the rendered HTML page. By default it uses the partial for the model doing the broadcast. But it's easily overridden.

Setup the main view with turbo_stream_from and render the partial that will be changed by the broadcast in a container with an id, verification_status.

/ show.html.slim
section.container.mx-auto.p-4.mb-8
  = turbo_stream_from @profile

  #verification_status
    == render 'verify_id', profile: @profile

/ _status.html.slim
/ SUCCEED Verification
- if profile.result == RESULTS.succeed
  p
    |  That worked!

/ FAILED Verification
- if profile.result == RESULTS.failed
  p
    |  Oops that failed :(

The Broadcast

Now, from a background job, response to a webhook, or where ever; you can broadcast the update.

profile.broadcast_action :update, target: "verification_status", partial: "profile/status"

Make sure to include Turbo::Broadcastable in the model.

class Profile < ApplicationRecord
  include Turbo::Broadcastable

  # ...
end

Tests

To make sure whatever should broadcast is broadcasting you can use ActionCable::TestHelper and Turbo::Streams::StreamName.

class Hooks::ProfileController < ActionDispatch::IntegrationTest
  include ActionCable::TestHelper
  include Turbo::Streams::StreamName

  test "should handle callback" do
    profile = create(:profile)

    assert_broadcasts stream_name_from(profile), 1 do
      get "/hooks/profile/callback/#{profile.id}?result=succeed"
    end

    assert_response :success
  end
end