Pages Loader ES6 Module(with Parallelism support) for Ember

pages-loader.js

import Ember from "ember";

const { RSVP } = Ember;

export function loadPagesInParallel(recordsPromise) {
  return recordsPromise.then(getPagesPromisesInParallel).then(waitForAllPromises);
}

export function loadPages(recordsPromise) {
  return recordsPromise.then(getPagesPromises).then(waitForAllPromises);
}

function waitForAllPromises(promises) {
  return RSVP.all(promises)
             .then((allRecords) => {
               return allRecords.reduce((allRecords, records) => allRecords.concat(records.toArray()), []);
             });
}

function getPagesPromisesInParallel(records) {
  return [RSVP.resolve(records), ...getPagesToLoad(records).map(page => loadPage(records, page))];
}

function getPagesPromises(records) {
  return getPagesPromisesInChain(records);
}

function getPagesPromisesInChain(records) {
  return getPagesToLoad(records).reduce((promises, _, i) => {
    return promises.concat([promises[i].then(loadNextPage)]);
  }, [RSVP.resolve(records)]);
}

function getPagesToLoad({ meta: { "total-pages": totalPages } }) {
  return [...Array(totalPages).keys()].map(p => p + 1).slice(1);
}

function loadNextPage(records) {
  return loadPage(records, records.meta['current-page'] + 1);
}

function loadPage(records, page) {
  return records.store.query(
    records.get("firstObject._internalModel.modelName"),
    Object.assign({}, records.query, { page })
  );
}