Function _$didUpdate

packages/reactive-element/src/reactive-element.ts:1547–1570

(changedProperties: PropertyValues)

  // Note, this is an override point for polyfill-support.
  // @internal
  _$didUpdate(changedProperties: PropertyValues) {
    this.__controllers?.forEach((c) => c.hostUpdated?.());
    if (!this.hasUpdated) {
      this.hasUpdated = true;
      this.firstUpdated(changedProperties);
    }
    this.updated(changedProperties);
    if (
      DEV_MODE &&
      this.isUpdatePending &&
      (this.constructor as typeof ReactiveElement).enabledWarnings!.includes(
        'change-in-update'
      )
    ) {
      issueWarning(
        'change-in-update',
        `Element ${this.localName} scheduled an update ` +
          `(generally because a property was set) ` +
          `after an update completed, causing a new update to be scheduled. ` +
          `This is inefficient and should be avoided unless the next update ` +
          `can only be scheduled as a side effect of the previous update.`
      );
    }
  }

  private __markUpdated() {
    this._$changedProperties = new Map();