@prg/gatsby-source-something-whatever/src/download-asset.js

something something whatever who gives a crap.

import { createRemoteFileNode } from 'gatsby-source-filesystem';

import { formatMsg } from './util';
import { PLUGIN_NAME, TYPE_PREFIX, IMAGE } from './constants';


export const downloadImagesAndCreateFileNodes = async (helpers, PARENT_TYPE) => {
  const {
    actions: { createNode, touchNode },
    createNodeId,
    store,
    cache,
    getNodes,
    reporter,
  } = helpers;

  const imageNodes = getNodes().filter(
    node =>
      node.internal.owner === PLUGIN_NAME &&
      node.internal.type === `${TYPE_PREFIX}${IMAGE}`
  );

  let newNodesCount = 0;

  const images = await Promise.all(
    imageNodes.map(async node => {
      try {
        const url = node.src.split('?')[0];
        const imageDataCacheKey =  `${TYPE_PREFIX}__${IMAGE}__${url}`;
        const cacheRemoteData = await cache.get(imageDataCacheKey);

        // Avoid downloading the asset again if it's been cached
        if (cacheRemoteData) {
          touchNode({ nodeId: cacheRemoteData.fileNodeID });

          return cacheRemoteData.fileNodeID;
        }

        newNodesCount = newNodesCount + 1;

        const fileNode = await createRemoteFileNode({
          url,
          parentNodeId: node.id,
          store,
          cache,
          createNode,
          createNodeId,
          reporter,
        });

        await cache.set(imageDataCacheKey, { fileNodeID: fileNode.id });

        if (fileNode) {
          node.localFile___NODE = fileNode.id;
        }

        return node;
      } catch (error) {
        helpers.reporter.panicOnBuild(`An error occurred in ${PLUGIN_NAME}.`)

        console.log(`error`, error);

        return Promise.resolve();
      }
    })
  );

  console.log(formatMsg(`Downloaded ${newNodesCount} new image files.`));

  return images;
};