bootstrap-vue-3/src/utils/classes/BvEvent.ts

Early (but lovely) implementation of Vue 3, Bootstrap 5 and Typescript

/**
 * Items that are omitted from the BvEventInit constructor arg
 */
type BvEventConstructorOmittables = 'eventType' | 'defaultPrevented'

export type {BvEventConstructorOmittables}

/**
 * @external
 */
export default class BvEvent {
  readonly cancelable: boolean = true
  readonly componentId: string | null = null
  private _defaultPrevented = false
  readonly eventType: string = ''
  readonly nativeEvent: string | null = null
  private _preventDefault: () => void
  readonly relatedTarget: string | null = null
  readonly target: EventTarget | null = null
  // Readable by everyone,
  // But only overwritten by inherrited constructors
  public get defaultPrevented() {
    return this._defaultPrevented
  }
  protected set defaultPrevented(prop) {
    this._defaultPrevented = prop
  }
  // I think this is right
  // We want to be able to have it callable to everyone,
  // But only overwritten by inherrited constructors
  public get preventDefault() {
    return this._preventDefault
  }
  // This may not be correct, because it doesn't get correct type inferences in children
  // Ex overwrite this.preventDefault = () => true is valid. Could be a TS issue
  protected set preventDefault(setter: () => void) {
    this._preventDefault = setter
  }

  constructor(
    eventType: string,
    eventInit: Partial<Omit<BvEvent, BvEventConstructorOmittables>> = {}
  ) {
    if (!eventType) {
      throw new TypeError(
        `Failed to construct '${this.constructor.name}'. 1 argument required, ${arguments.length} given.`
      )
    }

    // Merge defaults first, the eventInit, and the type last
    // so, it can't be overwritten
    Object.assign(this, BvEvent.Defaults, eventInit, {eventType})

    this._preventDefault = function _preventDefault() {
      if (this.cancelable) {
        this.defaultPrevented = true
      }
    }
  }

  static get Defaults() {
    return {
      cancelable: true,
      componentId: null,
      eventType: '',
      nativeEvent: null,
      relatedTarget: null,
      target: null,
    }
  }
}