FleetAdmiralJakob 🗕 🗗 🗙•4mo ago

Return undefined if param is not there

In this code cityById could be undefined and I want that this checks this and then weatherData gets undefined. Problem: I can't wrap this in a condition because of React's Hook Rules

  const weatherData = api.weather.getWeather.useQuery(
    {
      coordinates: cityById.coord,
      timezone: dayjs.tz.guess(),
      lang: locale,
    },
    { refetchOnWindowFocus: false, staleTime: 1000 * 60 * 60 /* 1 hour */ },
  );

  const weatherData = api.weather.getWeather.useQuery(
    {
      coordinates: cityById.coord,
      timezone: dayjs.tz.guess(),
      lang: locale,
    },
    { refetchOnWindowFocus: false, staleTime: 1000 * 60 * 60 /* 1 hour */ },
  );

4 Replies

FleetAdmiralJakob 🗕 🗗 🗙•4mo ago

After some digging I think this is not possible without sending a request to the server so maybe I have to make a feature request

Dani;•4mo ago

I usually end up using non-null assertion when I have to deal with situations like this

  const weatherData = api.weather.getWeather.useQuery(
    {
      coordinates: cityById!.coord,
      //                   ^ non-null assertion
      timezone: dayjs.tz.guess(),
      lang: locale,
    },
    { 
        enabled: !!cityById,
        //           ^ disable the query
        refetchOnWindowFocus: false,
        staleTime: 1000 * 60 * 60 /* 1 hour */
     },
  );

  const weatherData = api.weather.getWeather.useQuery(
    {
      coordinates: cityById!.coord,
      //                   ^ non-null assertion
      timezone: dayjs.tz.guess(),
      lang: locale,
    },
    { 
        enabled: !!cityById,
        //           ^ disable the query
        refetchOnWindowFocus: false,
        staleTime: 1000 * 60 * 60 /* 1 hour */
     },
  );

FleetAdmiralJakob 🗕 🗗 🗙•4mo ago

OK, weird. I tried this but the query still runs even with the enabled prop but I will try it again

FleetAdmiralJakob 🗕 🗗 🗙•4mo ago

@Dani; KATT sent me this part of the docs so I think I will try them: https://trpc.io/docs/client/react/disabling-queries#typesafe-conditional-queries-using-skiptoken

Disabling Queries | tRPC

To disable queries, you can pass skipToken as the first argument to useQuery or useInfiniteQuery. This will prevent the query from being executed.