Hi I was wondering if anyone know how to get a store's current state once without having to subscribe to it. I'm currently using ngrx to subscribe to the store and access its state to set a component's attribute, but since I'm subscribed this attribute is constantly refreshing. So I'm looking for a way to obtain this attribute just once so that I can display data without it refreshing constantly.
Just in case, this happens inside my component's constructor.
I've been trying something like this:
_store.select('storeData.correlationData');
When subscribing I would access like this:
_store.subscribe(
(state) => {
this.correlationData = state.storeData.correlationData;
}
);
EDIT
Applciation State:
export interface ApplicationState {
uiState: UiState;
storeData: StoreData;
}
You can create getState() function, put it in a shared module and import where needed. The key is to make it synchronous by using take(1) operator:
export function getState(store: any, selector: string) {
let _state: any;
store.take(1).subscribe(o => _state = o);
return _state;
}
Here's more advanced version I'm using:
export function getState(store: any, selector?: any) {
let _state: any;
let state$: any;
if (typeof selector === 'string' && /\./g.test(selector)) {
state$ = store.pluck(...selector.split('.'));
} else if (typeof selector === 'string') {
state$ = store.map(state => state[selector]);
} else if (typeof selector === 'function') {
state$ = store.map(state => selector(state));
} else {
state$ = store;
}
state$.take(1)
.subscribe(o => _state = o);
return _state;
}
With this you can get state in few different ways:
getState(this.store) // all data in Store
getState(this.store, 'users')
getState(this.store, state => state.users)
getState(this.store, 'users.address.street') // Cool!
As @Maximes pointed out in comments, you should try to use Observables directly in your code and use this method for testing.