ngrx Load data from server only if the store is empty

Question

I have a static set of data, a list of countries, that are used on some components. This data is loaded upon the ngOnInit() of these components but I\'d like to

Answer 1

You can select the countries from the store within effects, if they are represented in the store we ignore the action, if not we fetch the countries.

@Effect()
getOrder = this.actions.pipe(
  ofType(ActionTypes.GetOrder),
  withLatestFrom(this.store.pipe(select(getOrders))),
  filter(([{payload}, orders]) => !!orders[payload.orderId])
  mergeMap([{payload}] => {
    ...
  })
)

For more info see Start using ngrx/effects for this.