Question: Provide restApiResponse in async way

[simonvomeyser]

Hey, first of all thank you for your awesome work on this project, used it a ton lately, works so good! 👍

I have a question regarding the JSON data (restApiResponse) used for the type composer. Is there any technique that you know of to provide this data in an asynchronous way?

By now, I would get a data snapshot from the resource I am trying to integrate into my app, save it to a file and use that data during build to create the type as shown in the examples. It would be so awesome to be able to provide just an endpoint and have the type be created at runtime.

Feel free to close this since it is not really an issue and I know OSS takes a lot of time, just wanted to know if you have any experience with this. :)

best
Simon

[borodayev]

Hi, Simon! Thank you, we are glad to hear that it was the helpful tool for you. To building schema asynchronously you should configure the express-graphql like this:

app.use(
  '/graphql',
  graphqlHTTP(async req => ({
    schema: await mySchema,
    graphiql: true,
    context: req,
  }))
);

It should work. If you have any questions do not hesitate to ask.

[borodayev]

Moreover, you have to get schema asynchronously as well. I mean you should rewrite the Schema.js and add there an async function where you will fetch data from URL and build the TypeComposer, then build and return the schema:

export const buildAsyncSchema = async (): Promise<GraphQLSchema> => {
  const url = `https://swapi.co/api/people/1`;
  const data = await fetch(url);
  const jsonData = await data.json();

  const PeopleTC = composeWithJson('People', jsonData);
  PeopleTC.addResolver({
    name: 'findById',
    type: PeopleTC,
    args: {
      id: 'Int!',
    },
    resolve: rp => {
      return fetch(`https://swapi.co/api/people/${rp.args.id}/`).then(r => r.json());
    },
  });

  GQC.rootQuery().addFields({
    person: PeopleTC.getResolver('findById'),
  });

  const schema = GQC.buildSchema();
  return schema;
};

In app.js:

import { buildAsyncSchema } from './Schema';

const PORT = 4000;
const app = express();
const promiseSchema = buildAsyncSchema();

app.use(
  '/graphql',
  graphqlHTTP(async req => ({
    schema: await promiseSchema,
    graphiql: true,
    context: req,
  }))
);

So, express-graphql will get a promise and will build the schema at runtime

[simonvomeyser]

Wow, thank you so much for your detailed answer @FrankAst! It did not occur to me that I could define the whole schema asynchronously, I was trying stuff on a per type basis.

This solves my problem :)

The possibilities of graphql in this field are so interesting, this seems to be the REST Version of Schema Stitching presented by Apollo (https://www.apollographql.com/docs/graphql-tools/schema-stitching.html)

Again, a big thank you for your answer, you helped me a ton, I will close this issue :) 👍

[borodayev]

You are welcome!