relay-fetch.js

import _ from 'lodash';
import React from 'react';
import Relay from 'react-relay';
import RelayQuery from 'react-relay/lib/RelayQuery';
import GraphQLStoreQueryResolver from 'react-relay/lib/GraphQLStoreQueryResolver'
import RelayFragmentPointer from 'react-relay/lib/RelayFragmentPointer';
import RelayMetaRoute from 'react-relay/lib/RelayMetaRoute';

class DummyComponent extends React.Component {
  render() {
    return null;
  }
}

function getQueryFragment(Container, route, fragmentName, args) {
  const fragmentReference = Container.getFragment(fragmentName, args);
  const concreteFragment = fragmentReference.getFragment(args)

  const metaRoute = RelayMetaRoute.get(route.name);
  return RelayQuery.Fragment.create(concreteFragment, metaRoute, args);
}

export default {
  fetch(route, args, fragments) {
    const environment = Relay.Store;
    const store = environment.getStoreData();

    const DummyContainer = Relay.createContainer(DummyComponent, {
      initialVariables: args,
      fragments
    });

    const queryToRecord = (query, name) => {
      // get container fragment based on query
      const queryFragment = getQueryFragment(DummyContainer, route, name, args);

      // create fragment pointer (dataid reference from relay store)
      const fp = RelayFragmentPointer.createForRoot(store.getQueuedStore(), query);

      if (fp && fp.__dataID__) {
        // resolve the query on the store
        const resolver = new GraphQLStoreQueryResolver(store, queryFragment);
        return resolver.resolve(queryFragment, fp.__dataID__);
      } else {
        return null;
      }
    }

    return new Promise((resolve, reject) => {
      const querySet = Relay.getQueries(DummyContainer, route);

      // execute the query
      environment.primeCache(querySet, readyState => {
        if (readyState.ready) {
          resolve(_.mapValues(querySet, queryToRecord));
        } else if (readyState.error || readyState.aborted) {
          reject(readyState.error || new Error('Unexpected error on query'));
        }
      });
    });
  }
}