@apollo/react-hooks

npm install @apollo/react-hooks

import { useQuery } from '@apollo/react-hooks';
import gql from 'graphql-tag';

const GET_GREETING = gql`
  query getGreeting($language: String!) {
    greeting(language: $language) {
      message
    }
  }
`;

function Hello() {
  const { loading, error, data } = useQuery(GET_GREETING, {
    variables: { language: 'english' },
  });
  if (loading) return <p>Loading ...</p>;
  return <h1>Hello {data.greeting.message}!</h1>;
}

function useQuery<TData = any, TVariables = OperationVariables>(
  query: DocumentNode,
  options?: QueryHookOptions<TData, TVariables>,
): QueryResult<TData, TVariables> {}

import { useLazyQuery } from "@apollo/react-hooks";
import gql from "graphql-tag";

const GET_GREETING = gql`
  query getGreeting($language: String!) {
    greeting(language: $language) {
      message
    }
  }
`;

function Hello() {
  const [loadGreeting, { called, loading, data }] = useLazyQuery(
    GET_GREETING,
    { variables: { language: "english" } }
  );
  if (called && loading) return <p>Loading ...</p>
  if (!called) {
    return <button onClick={() => loadGreeting()}>Load greeting</button>
  }
  return <h1>Hello {data.greeting.message}!</h1>;
}

function useLazyQuery<TData = any, TVariables = OperationVariables>(
  query: DocumentNode,
  options?: LazyQueryHookOptions<TData, TVariables>,
): [
  (options?: QueryLazyOptions<TVariables>) => void,
  QueryResult<TData, TVariables>
] {}

import { useMutation } from '@apollo/react-hooks';
import gql from 'graphql-tag';

const ADD_TODO = gql`
  mutation AddTodo($type: String!) {
    addTodo(type: $type) {
      id
      type
    }
  }
`;

function AddTodo() {
  let input;
  const [addTodo, { data }] = useMutation(ADD_TODO);

  return (
    <div>
      <form
        onSubmit={e => {
          e.preventDefault();
          addTodo({ variables: { type: input.value } });
          input.value = '';
        }}
      >
        <input
          ref={node => {
            input = node;
          }}
        />
        <button type="submit">Add Todo</button>
      </form>
    </div>
  );
}

function useMutation<TData = any, TVariables = OperationVariables>(
  mutation: DocumentNode,
  options?: MutationHookOptions<TData, TVariables>,
): MutationTuple<TData, TVariables> {}

const COMMENTS_SUBSCRIPTION = gql`
  subscription onCommentAdded($repoFullName: String!) {
    commentAdded(repoFullName: $repoFullName) {
      id
      content
    }
  }
`;

function DontReadTheComments({ repoFullName }) {
  const {
    data: { commentAdded },
    loading,
  } = useSubscription(COMMENTS_SUBSCRIPTION, { variables: { repoFullName } });
  return <h4>New comment: {!loading && commentAdded.content}</h4>;
}

function useSubscription<TData = any, TVariables = OperationVariables>(
  subscription: DocumentNode,
  options?: SubscriptionHookOptions<TData, TVariables>,
): {
  variables: TVariables;
  loading: boolean;
  data?: TData;
  error?: ApolloError;
} {}

function SomeComponent() {
  const client = useApolloClient();
  // `client` is now set to the `ApolloClient` instance being used by the
  // application (that was configured using something like `ApolloProvider`)
}

function useApolloClient(): ApolloClient<object> {}