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StoreGroup

Interface

constructor(stateStoreMapping: StoreMap<T>);
    shouldStateUpdate(prevState: any, nextState: any): boolean;
    onChange(handler: (stores: Array<Store<T>>, details?: StoreGroupReasonForChange) => void): () => void;
    release(): void;

constructor(stateStoreMapping: StoreMap<T>);

Initialize this StoreGroup with a stateName-store mapping object.

The rule of initializing StoreGroup is that "define the state name of the store".

Example

Initialize with store-state mapping object.

class AStore extends Store {
    getState() {
        return "a value";
    }
}
class BStore extends Store {
    getState() {
        return "b value";
    }
}
const aStore = new AStore();
const bStore = new BStore();
const storeGroup = new StoreGroup({
    a: aStore, // stateName: store
    b: bStore
});
console.log(storeGroup.getState());
// { a: "a value", b: "b value" }

shouldStateUpdate(prevState: any, nextState: any): boolean;

Use shouldStateUpdate() to let StoreGroup know if a event is not affected. The default behavior is to emitChange on every life-cycle change, and in the vast majority of cases you should rely on the default behavior. Default behavior is shallow-equal prev/next state.

Example

If you want to use Object.is to equal states, overwrite following.

shouldStateUpdate(prevState, nextState) {
   return !Object.is(prevState, nextState)
}

onChange(handler: (stores: Array<Store<T>>, details?: StoreGroupReasonForChange) => void): () => void;

Observe changes of the store group.

For example, the user can change store using Store#setState manually. In this case, the details is defined and report.

Contrast, almin try to update store in a lifecycle(didUseCase, completeUseCase etc...). In this case, the details is not defined and report.

StoreGroup#onChange workflow: https://code2flow.com/mHFviS

release(): void;

Release all events handler. You can call this when no more call event handler

← StoreUseCase →