I have two entities, Games and Jackpots:
Game interface
{
id: string,
name: string
}
Jackpot interface
{
game: string,
amount: number
}
First I have two observables, one to get games and one to get jackpots.
And after getting the data i want to merge the data of jackpots into games based on id. And since the jackpots observale should get the data each seconds i used the operator timer to do so. So here's my implementation:
private getGames = (category: string): Observable<IGame[]> => {
return timer(0, 3000).pipe(
mergeMap(() => combineLatest([this.gameService.getGames(), this.gameService.getJackpots()])),
map(([games, jackpots]) => {
return games?.filter(game => game?.categories?.includes(category))?.map(game => {
return { ...game, jackpot: jackpots?.find(jackpot => jackpot?.game === game?.id) };
})
})
);
};
This implementation works fine and the data is fetched every 3 seconds. Now as you can see both Games and Jackpots observable get fetched every 3 seconds, My question is: is there a way to only run the Jackpots observable every 3 seconds, and exclude the Games observable from that timer.
combineLatest has two important properties:
You can set the timer only for the games Observable and combine it with the jackpots one.
private getGames = (category: string): Observable<IGame[]> => {
return combineLatest([
timer(0, 3000).pipe(mergeMap(() => this.gameService.getGames())),
this.gameService.getJackpots(),
]).pipe(
map(([games, jackpots]) => {
return games
?.filter((game) => game?.categories?.includes(category))
?.map((game) => {
return { ...game, jackpot: jackpots?.find((jackpot) => jackpot?.game === game?.id) };
});
})
);
};