Interface ReadableAtom

atom/index.d.ts:18–100

 * Store object.
 */
export interface ReadableAtom<Value = any> {
  /**
   * Get store value.
   *
   * In contrast with {@link ReadableAtom#value} this value will be always
   * initialized even if store had no listeners.
   *
   * ```js
   * $store.get()
   * ```
   *
   * @returns Store value.
   */
  get(): Value

  /**
   * Low-level attribute to read store’s initial value.
   */
  readonly init: undefined | Value

  /**
   * Listeners count.
   */
  readonly lc: number

  /**
   * Subscribe to store changes.
   *
   * In contrast with {@link Store#subscribe} it do not call listener
   * immediately.
   *
   * @param listener Callback with store value and old value.
   * @returns Function to remove listener.
   */
  listen(
    listener: (
      value: ReadonlyIfObject<Value>,
      oldValue: ReadonlyIfObject<Value>
    ) => void
  ): () => void

  /**
   * Low-level method to notify listeners about changes in the store.
   *
   * Can cause unexpected behaviour when combined with frontend frameworks
   * that perform equality checks for values, such as React.
   */
  notify(oldValue?: ReadonlyIfObject<Value>): void

  /**
   * Unbind all listeners.
   */
  off(): void

  /**
   * Subscribe to store changes and call listener immediately.
   *
   * ```