LobeHub Zustand State Management

Action Type Hierarchy

1. Public Actions

Main interfaces for UI components:

• Naming: Verb form (createTopic, sendMessage)
• Responsibilities: Parameter validation, flow orchestration

2. Internal Actions (internal_*)

Core business logic implementation:

• Naming: internal_ prefix (internal_createTopic)
• Responsibilities: Optimistic updates, service calls, error handling
• Should not be called directly by UI

3. Dispatch Methods (internal_dispatch*)

State update handlers:

• Naming: internal_dispatch + entity (internal_dispatchTopic)
• Responsibilities: Calling reducers, updating store

When to Use Reducer vs Simple set

Use Reducer Pattern:

• Managing object lists/maps (messagesMap, topicMaps)
• Optimistic updates
• Complex state transitions

Use Simple set:

• Toggling booleans
• Updating simple values
• Setting single state fields

Optimistic Update Pattern

typescript
1internal_createTopic: async (params) => {
2  const tmpId = Date.now().toString();
3
4  // 1. Immediately update frontend (optimistic)
5  get().internal_dispatchTopic(
6    { type: 'addTopic', value: { ...params, id: tmpId } },
7    'internal_createTopic'
8  );
9
10  // 2. Call backend service
11  const topicId = await topicService.createTopic(params);
12
13  // 3. Refresh for consistency
14  await get().refreshTopic();
15  return topicId;
16},

Delete operations: Don't use optimistic updates (destructive, complex recovery)

Naming Conventions

Actions:

• Public: createTopic, sendMessage
• Internal: internal_createTopic, internal_updateMessageContent
• Dispatch: internal_dispatchTopic
• Toggle: internal_toggleMessageLoading

State:

• ID arrays: messageLoadingIds, topicEditingIds
• Maps: topicMaps, messagesMap
• Active: activeTopicId
• Init flags: topicsInit

Detailed Guides

• Action patterns: references/action-patterns.md
• Slice organization: references/slice-organization.md

Class-Based Action Implementation

We are migrating slices from plain StateCreator objects to class-based actions.

Pattern

• Define a class that encapsulates actions and receives (set, get, api) in the constructor.
• Use #private fields (e.g., #set, #get) to avoid leaking internals.
• Prefer shared typing helpers:
  • StoreSetter<T> from @/store/types for set.
  • Pick<ActionImpl, keyof ActionImpl> to expose only public methods.
• Export a create*Slice helper that returns a class instance.

ts
1type Setter = StoreSetter<HomeStore>;
2export const createRecentSlice = (set: Setter, get: () => HomeStore, _api?: unknown) =>
3  new RecentActionImpl(set, get, _api);
4
5export class RecentActionImpl {
6  readonly #get: () => HomeStore;
7  readonly #set: Setter;
8
9  constructor(set: Setter, get: () => HomeStore, _api?: unknown) {
10    void _api;
11    this.#set = set;
12    this.#get = get;
13  }
14
15  useFetchRecentTopics = () => {
16    // ...
17  };
18}
19
20export type RecentAction = Pick<RecentActionImpl, keyof RecentActionImpl>;

Composition

• In store files, merge class instances with flattenActions (do not spread class instances).
• flattenActions binds methods to the original class instance and supports prototype methods and class fields.

ts
1const createStore: StateCreator<HomeStore, [['zustand/devtools', never]]> = (...params) => ({
2  ...initialState,
3  ...flattenActions<HomeStoreAction>([
4    createRecentSlice(...params),
5    createHomeInputSlice(...params),
6  ]),
7});

Multi-Class Slices

• For large slices that need multiple action classes, compose them in the slice entry using flattenActions.
• Use a local PublicActions<T> helper if you need to combine multiple classes and hide private fields.

ts
1type PublicActions<T> = { [K in keyof T]: T[K] };
2
3export type ChatGroupAction = PublicActions<
4  ChatGroupInternalAction & ChatGroupLifecycleAction & ChatGroupMemberAction & ChatGroupCurdAction
5>;
6
7export const chatGroupAction: StateCreator<
8  ChatGroupStore,
9  [['zustand/devtools', never]],
10  [],
11  ChatGroupAction
12> = (...params) =>
13  flattenActions<ChatGroupAction>([
14    new ChatGroupInternalAction(...params),
15    new ChatGroupLifecycleAction(...params),
16    new ChatGroupMemberAction(...params),
17    new ChatGroupCurdAction(...params),
18  ]);

Store-Access Types

• For class methods that depend on actions in other classes, define explicit store augmentations:
  • ChatGroupStoreWithSwitchTopic for lifecycle switchTopic
  • ChatGroupStoreWithRefresh for member refresh
  • ChatGroupStoreWithInternal for curd internal_dispatchChatGroup

Do / Don't

• Do: keep constructor signature aligned with StateCreator params (set, get, api).
• Do: use #private to avoid set/get being exposed.
• Do: use flattenActions instead of spreading class instances.
• Don't: keep both old slice objects and class actions active at the same time.