Apollo

Apollo is a GraphQL client. It performs GraphQL operations and returns results in JSON. We are using apollo-client as the main module for Apollo.

Initializing Apollo Client

// load required modules
const ApolloClient = require("apollo-client").ApolloClient;
const InMemoryCache = require("apollo-cache-inmemory").InMemoryCache;
const createHttpLink = require("apollo-link-http").createHttpLink;
const fetch = require("node-fetch");
const gql = require("graphql-tag");

// create apollo object (don't forget to import globalVars)
const apollo = new ApolloClient({
    link: createHttpLink({ uri: globalVars.gqlURL, fetch: fetch }),
    cache: new InMemoryCache()
});

Using Apollo

Simple Querying

Using Apollo is simple. Simply put a GraphQL query in the query object like the example below.

apollo.query({ query: gql`[GraphQL query here]` });

It then returns a JavaScript object.

Example: A function that sends a login request to the API and returns member information.

const getMember = (usr, pwd) => {
    return apollo.query({
        query: gql`
            {
                login(username: "${usr}", password: "${pwd}") {
                    member {
                        id, username, firstName, lastName, email
                    },
                    token
                }
            }
        `
    });
};

Querying with Authentication

Some queries require a bearer authentication token. This token is acquired when a user logs into the system (notice the token key in the example above). To use a token with Apollo, see the example below.

// load one more module
const setContext = require("apollo-link-context").setContext;

// declare a sample token
let amazingToken = "thisissowrongonsomanylevels";

// add a token to the header
const authLink = setContext((_, { headers }) => {
    return {headers: { authorization: token ? `bearer${amazingToken}` : "" }};
});

// create apollo object
const apollo = new ApolloClient({
    link: authLink.concat(
        createHttpLink({ uri: globalVars.gqlURL, fetch: fetch })
    ),
    cache: new InMemoryCache()
});

// use apollo as normal
apollo.query({
    query: gql`
        {
            space(id: "a10ep-7g32a-kqn5x") {
                id, name, description, capacity, isAvailable
            }
        }
    `
});