Application State Management Overview

The decorators described in the previous topics are used to share state variables within a page, that is, within a component tree. If you want to share state data at the application level or across multiple pages, you would need to apply application-level state management. ArkTS provides a wide variety of application state management capabilities:

• LocalStorage: API for storing the UI state, usually used for state sharing within a UIAbility or between pages.

• AppStorage: special, singleton LocalStorage object within the application, which is created by the UI framework at application startup and provides the central storage for application UI state attributes.

• PersistentStorage: API for persisting application attributes. It is usually used together with AppStorage to persist selected AppStorage attributes to the disk so that their values are the same upon application re-start as they were when the application was closed.

• Environment: a range of environment parameters regarding the device where the application runs. The environment parameters are synchronized to AppStorage and can be used together with AppStorage.