subscriptionExchange and SSR

[aldis-ameriks]

What's the optimal way to handle subscriptionExchange and ssr?

I'm now doing the following, which seems to work. But made me wonder what's the recommended way and/or how others are handling it?

  if (!isServerSide) {
    const subscriptionClient = new SubscriptionClient(config.apiGraphqlWsEndpoint, { reconnect: true });

    exchanges.push(
      subscriptionExchange({
        forwardSubscription(operation) {
          return subscriptionClient.request(operation);
        },
      })
    );
  }

[kitten]

I'm not quite sure what the question here is. By default useSubscription shouldn't be taken into account for SSR, meaning that no subscription will actually be executed for runs using react-ssr-prepass for instance. So it's safe to either add a subscriptionExchange or leave it out for SSR.

[aldis-ameriks]

Based on types subscriptionExchange cannot be initialized without defining forwardSubscription.
However, when doing SSR, I want to skip the subscriptions client.
To work around that, I'm simply skipping the whole exchange altogether when doing SSR.
That's what the above example achieves.

But this results in warnings being thrown server side.

No exchange has handled operations of type "subscription". Check whether you've added an exchange responsible for these operations.

So this made me wonder if there's a better way of setting up the subscriptionExchange, that sets up the subscriptions client on browser, skips it in node, but also avoids the warnings, that occur when doing the server side rendering.

[aldis-ameriks]

After updating urql to 1.10.3, the warnings are no longer being logged when skipping subscriptionExchange on node.