How to use async/await pattern with gRPC Web?

Question

I'm developing a Vue.js web application and I'm using gRPC to assure the communication.

In the frontend, I'm using the web version of gRPC: grpc-web.

Everything is working just fine; however, when I'm doing an API call in my store, e.g.:

async fetchEcho() {
    const echoService = new EchoServiceClient('http://localhost:8080', null, null);

    const request = new EchoRequest();
    request.setMessage('Hello World!');

    const call = echoService.echo(request, {'custom-header-1': 'value1'},
      (err: grpcWeb.Error, response: EchoResponse) => {
        console.log(response.getMessage());
    });
}

How can I use the async/await pattern when making the call in my Vue file, e.g.:

await fetchEcho();
// ...

And await until the API call has finished to resume my the course of my program?

Thanks!

Answer 1

I'm using ServicePromiseClient, the example would be something like this:

const echoServiceClient = new EchoServicePromiseClient("http://localhost:8080", null, null);

Then I'm able to create async functions for fetching like this:

async function fetchEcho() {
    const echoReq = new EchoRequest();
    echoReq.setMessage("Hello world!");
    try {
        const response = await echoServiceClient.echo(echoReq, {});
        return response;
    } catch (error) {
        console.log(error);
        return null;
    }
}