Freika/dawarich · warning

[MapChannel] ActionCable consumer not available

Error message

[MapChannel] ActionCable consumer not available

What it means

Before creating any channel subscription, this module defensively checks that an ActionCable consumer object was passed in. A null/undefined consumer means the cable setup code (importing @rails/actioncable and calling createConsumer) never ran or returned nothing; the function returns an empty subscription set, so family locations, live points, and track updates are all disabled for the session.

Source

Thrown at app/javascript/maps_maplibre/channels/map_channel.js:24

 * @param {Object} options - { received, connected, disconnected, enableLiveMode }
 * @returns {Object} Subscriptions object with multiple channels
 */
export function createMapChannel(options = {}) {
  const { enableLiveMode = false, ...callbacks } = options
  const subscriptions = {
    family: null,
    points: null,
    tracks: null,
  }

  console.log(
    "[MapChannel] Creating channels with enableLiveMode:",
    enableLiveMode,
  )

  // Defensive check - consumer might not be available
  if (!consumer) {
    console.warn("[MapChannel] ActionCable consumer not available")
    return {
      subscriptions,
      unsubscribeAll() {},
    }
  }

  // Subscribe to family locations if family feature is enabled
  try {
    const familyFeaturesElement = document.querySelector(
      "[data-family-members-features-value]",
    )
    const features = familyFeaturesElement
      ? JSON.parse(familyFeaturesElement.dataset.familyMembersFeaturesValue)
      : {}

    if (features.family) {
      subscriptions.family = consumer.subscriptions.create(
        "FamilyLocationsChannel",

View on GitHub (pinned to 97fad417c5)

Solutions

1. Trace where the consumer argument originates — it must come from createConsumer() in @rails/actioncable; confirm that import resolves in the bundle
2. Check the browser console for a failed import of @rails/actioncable before this warning
3. In tests, inject a minimal fake consumer ({ subscriptions: { create: () => ({ unsubscribe() {} }) } }) or assert the no-subscription path
4. Ensure the consumer module is imported and executed before map channels are set up

Example fix

// before
// consumer may be undefined if bootstrap failed
setupMapChannels(consumer, callbacks, enableLiveMode)
// after
import { createConsumer } from "@rails/actioncable"
let consumer = null
try {
  consumer = createConsumer()
} catch (e) {
  console.warn("[MapChannel] Could not create ActionCable consumer", e)
}
setupMapChannels(consumer, callbacks, enableLiveMode)

if (!consumer || typeof consumer.subscriptions?.create !== "function") {
  // Skip realtime entirely — the map still works without live updates
  return { subscriptions, unsubscribeAll() {} }
}

/** @param {unknown} c @returns {boolean} */
function isActionCableConsumer(c) {
  return Boolean(
    c &&
    typeof c === "object" &&
    c.subscriptions &&
    typeof c.subscriptions.create === "function"
  )
}

When it happens

Trigger: createConsumer() moved or renamed in the import chain so undefined is passed into setupMapChannels; the cable bootstrap module failing to load (bundler/tree-shaking issue); an exception during module init swallowing consumer creation; running in an environment where ActionCable is intentionally absent (tests, static previews).

Common situations: Refactors of the channels bootstrap module changing its export shape; test harnesses rendering the map without ActionCable; bundler misconfiguration dropping @rails/actioncable from the chunk that calls this module.

Related errors

• [MapChannel] Failed to subscribe to family channel:
• [MapChannel] Failed to subscribe to tracks channel:
• [MapChannel] Failed to subscribe to points channel:
• [Realtime Controller] Maps controller not found
• [Realtime Controller] Points layer not found

AI-assisted analysis of Freika/dawarich@97fad417c5 (2026-08-21). Data as JSON: /api/errors/818adecbd5cfc976. Report an issue: GitHub.