Method constructor

packages/db/src/collection/subscription.ts:108–143

(
    private collection: CollectionImpl<any, any, any, any, any>,
    private callback: (changes: Array<ChangeMessage<any, any>>) => void,
    private options: CollectionSubscriptionOptions,
  )

  }

  constructor(
    private collection: CollectionImpl<any, any, any, any, any>,
    private callback: (changes: Array<ChangeMessage<any, any>>) => void,
    private options: CollectionSubscriptionOptions,
  ) {
    super()
    if (options.onUnsubscribe) {
      this.on(`unsubscribed`, (event) => options.onUnsubscribe!(event))
    }

    // Auto-index for where expressions if enabled
    if (options.whereExpression) {
      ensureIndexForExpression(options.whereExpression, this.collection)
    }

    const callbackWithSentKeysTracking = (
      changes: Array<ChangeMessage<any, any>>,
    ) => {
      callback(changes)
      this.trackSentKeys(changes)
    }

    this.callback = callbackWithSentKeysTracking

    // Create a filtered callback if where clause is provided
    this.filteredCallback = options.whereExpression
      ? createFilteredCallback(this.callback, options)
      : this.callback

    // Listen for truncate events to re-request data after must-refetch
    // When a truncate happens (e.g., from a 409 must-refetch), all collection data is cleared.
    // We need to re-request all previously loaded subsets to repopulate the data.
    this.truncateCleanup = this.collection.on(`truncate`, () => {
      this.handleTruncate()
    })
  }

  /**
   * Handle collection truncate event by resetting state and re-requesting subsets.