Implementing GraphQL subscriptions

Now that we've set up Apollo Client for GraphQL subscriptions, we'll learn how to use subscriptions to add some realtime features to our application.

In the server, we have added a Subscription type with two fields – onPostCommented and onPostLiked – to our GraphQL schema. Then, we implemented the required resolvers to push realtime updates to the client when a post is commented on or liked.

In this section, we are going to learn how to listen to realtime updates from the server. This process is similar to how we used queries to query for data, but instead of using the query operation, we use the subscription operation with the fields that need to be sent from the server. For the response, we get results every time new data is available on the server.

In our case, we'll implement the functionality for displaying new comments and likes on posts every time they are added by the users of the network without the need...