Interface MapStore

map/index.d.ts:46–136

  : AllKeys<StoreValue<SomeStore>>

export interface MapStore<
  Value extends object = any
> extends WritableAtom<Value> {
  /**
   * 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.
   * @param changedKey Key that was changed. Will present only if `setKey`
   *                   has been used to change a store. It is `undefined` when
   *                   changes were coalesced inside `batch`.
   * @returns Function to remove listener.
   */
  listen(
    listener: (
      value: ReadonlyIfObject<Value>,
      oldValue: ReadonlyIfObject<Value>,
      changedKey: AllKeys<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>, changedKey?: AllKeys<Value>): void

  /**
   * Change store value.
   *
   * ```js
   * $settings.set({ theme: 'dark' })
   * ```
   *
   * Operation is atomic, subscribers will be notified once with the new value.
   * `changedKey` will be undefined
   *
   * @param newValue New store value.
   */
  set(newValue: Value): void

  /**
   * Change key in store value.
   *
   * ```js
   * $settings.setKey('theme', 'dark')
   * ```
   *
   * To delete key set `undefined`.
   *
   * ```js
   * $settings.setKey('theme', undefined)
   * ```
   *