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moloch

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•Created by .westsaid on 10/12/2022 in #❓-help

How to use trpc react hooks from an external data source

Thanks for this repo, it was super helpful to me. Have you ever tried enabling tRPC's subscription support via websockets? struggling to get that working inside of Keystone.js's config

8 replies

TtRPC

•Created by moloch on 3/9/2023 in #❓-help

Cannot get subscription event to fire

np, and good luck!

8 replies

TtRPC

•Created by moloch on 3/9/2023 in #❓-help

Cannot get subscription event to fire

Ya I'm not sure how performant that is, but it seemed to be the only way I could get it to work when I was fiddling around

8 replies

TtRPC

•Created by moloch on 3/9/2023 in #❓-help

Cannot get subscription event to fire

that's great though

8 replies

TtRPC

•Created by moloch on 3/9/2023 in #❓-help

Cannot get subscription event to fire

I just used the redis npm package

8 replies

TtRPC

•Created by moloch on 3/9/2023 in #❓-help

Cannot get subscription event to fire

I also struggled with setting up redis. My current working example is much the result of brute force trial / error:

  onFact: publicProcedure.subscription(async ({ ctx }) => {
    if (!redisClient.isReady) {
      console.log("Redis client is not connected!");
      await redisClient.connect();
    }


    // return an `observable` with a callback which is triggered immediately
    return observable<CatFact>((emit) => {
      // define a listener function to handle incoming messages
      const listener = (message: string, channel: string) => {
        console.log(`Received message on channel ${channel}: ${message}`);

        if (channel === "cat-facts") {
          const fact = JSON.parse(message);
          // emit data to client
          emit.next(fact);
        }
      };

      // subscribe to the `cat-facts` channel in Redis
      const subscriber = redisClient.duplicate();
      subscriber.subscribe("cat-facts", listener);

      subscriber.connect();

      const onCatFact = (channel: string, message: string) => {
        if (channel === "cat-facts") {
          const fact = JSON.parse(message);
          // emit data to client
          emit.next(fact);
        }
      };
      // trigger `onCatFact()` when a message is published to the `cat-facts` channel
      subscriber.on("message", onCatFact);

      // unsubscribe function when client disconnects or stops subscribing
      return () => {
        // unsubscribe from the `cat-facts` channel in Redis
        subscriber.unsubscribe("cat-facts");
        subscriber.off("message", onCatFact);
      };
    });
  }),

  onFact: publicProcedure.subscription(async ({ ctx }) => {
    if (!redisClient.isReady) {
      console.log("Redis client is not connected!");
      await redisClient.connect();
    }


    // return an `observable` with a callback which is triggered immediately
    return observable<CatFact>((emit) => {
      // define a listener function to handle incoming messages
      const listener = (message: string, channel: string) => {
        console.log(`Received message on channel ${channel}: ${message}`);

        if (channel === "cat-facts") {
          const fact = JSON.parse(message);
          // emit data to client
          emit.next(fact);
        }
      };

      // subscribe to the `cat-facts` channel in Redis
      const subscriber = redisClient.duplicate();
      subscriber.subscribe("cat-facts", listener);

      subscriber.connect();

      const onCatFact = (channel: string, message: string) => {
        if (channel === "cat-facts") {
          const fact = JSON.parse(message);
          // emit data to client
          emit.next(fact);
        }
      };
      // trigger `onCatFact()` when a message is published to the `cat-facts` channel
      subscriber.on("message", onCatFact);

      // unsubscribe function when client disconnects or stops subscribing
      return () => {
        // unsubscribe from the `cat-facts` channel in Redis
        subscriber.unsubscribe("cat-facts");
        subscriber.off("message", onCatFact);
      };
    });
  }),

hope this helps!

8 replies

TtRPC

•Created by moloch on 3/9/2023 in #❓-help

Cannot get subscription event to fire

Thank you very much for the detailed response! The issue turned out to be caused by Next.js using different processes and therefor contexts between the two endpoints, I was using an EventEmitter to trigger the webhooks but each context had it's own isolated EventEmitter. Ended up switching to Redis to solve the issue 🤦‍♀️

8 replies

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