Using Drupal Subrequests from Javascript

example_usage_with_pagination.js

import makeDrupalSubrequest from '@/makeDrupalSubrequest';

const assetTypes = ['animal', 'land', 'plant'];

async main() {
    const filterQueryString = `filter[is_location]=1`;

    async function* paginateAssets() {
      const requests = assetTypes.map(assetType => ({
        id: assetType,
        path: `/api/asset/${assetType}?${filterQueryString}`,
        verb: 'GET',
      }));
      
      const pendingRequestsById = {};
      requests.forEach(r => pendingRequestsById[r.id] = r);

      while (Object.keys(pendingRequestsById).length > 0) {
        const responses = await makeDrupalSubrequest(Object.values(pendingRequestsById));

        const assets = responses.flatMap(r => r.data.data);

        for (let asset of assets) {
          yield asset;
        }

        responses.forEach(r => {
          const nextLink = r.data.links.next?.href;

          if (nextLink) {
            pendingRequestsById[r.requestId].path = nextLink;
          } else {
            delete pendingRequestsById[r.requestId];
          }
        });
      }
    }

    for await (let asset of paginateAssets(requests)) {
        console.log(`Asset '${asset.attributes.name}' is a location asset!`);
    }
}

main();

makeDrupalSubrequest.js

import axios from 'axios';

function createDrupalUrl(pathSuffix) {
  return new URL(pathSuffix, window.location.origin + '/');
}

// https://git.drupalcode.org/project/subrequests/-/blob/18b0d853f839f46a1bbed7cc7e2a3fd7b9820c46/src/Normalizer/JsonSubrequestDenormalizer.php#L96-117
const ACTION_BY_HTTP_VERB = {
  POST: 'create',
  PATCH: 'update',
  PUT: 'replace',
  DELETE: 'delete',
  HEAD: 'exists',
  OPTIONS: 'discover',
};

export default async function makeDrupalSubrequests(requests) {
  const subrequestBlueprint = requests.map(request => ({
    requestId: request.id || undefined,
    uri: createDrupalUrl(request.path),
    action: ACTION_BY_HTTP_VERB[request.verb] || 'view',
    headers: request.headers || {},
    body: request.body ? JSON.stringify(request.body) : undefined,
  }));

  const subrequestsResponse = await axios.post(createDrupalUrl('/subrequests?_format=json'), subrequestBlueprint, {
    headers: {
      'Content-Type': 'application/vnd.api+json',
      Accept: 'application/vnd.api+json',
    },
  });

  const responses = Object.keys(subrequestsResponse.data)
    .map(requestId => {
      const r = subrequestsResponse.data[requestId];

      return {
        requestId,
        data: JSON.parse(r.body),
        status: r.headers.status,
        headers: r.headers,
      };
    });

  return responses;
}