express-crud-router/lib/additionalAttributeHelpers.js

React Admin backend for Express. 1 line per resource! ORM agnostic.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.populateReferenceOne = exports.populateReferenceManyCount = exports.populateReferenceMany = exports.populateReference = void 0;

const populateReference = ({
  fetchAll,
  source,
  target = 'id'
}) => {
  const cache = new Cache();
  return async (record, {
    rows,
    req
  }) => {
    let referencesByTarget = cache.get(req);

    if (!referencesByTarget) {
      const references = await fetchAll(rows);
      referencesByTarget = references.reduce((referencesByTarget, reference) => {
        referencesByTarget[reference[target ?? 'id']] = reference;
        return referencesByTarget;
      }, {});
      cache.set(req, referencesByTarget);
    }

    return referencesByTarget[record[source]];
  };
};

exports.populateReference = populateReference;

const populateReferenceMany = ({
  fetchAll,
  source = 'id',
  target
}) => {
  const cache = new Cache();
  return async (record, {
    rows,
    req
  }) => {
    let referencesByTarget = cache.get(req);

    if (!referencesByTarget) {
      const references = await fetchAll(rows, req);
      referencesByTarget = references.reduce((referencesByTarget, reference) => {
        if (!referencesByTarget[reference[target]]) {
          referencesByTarget[reference[target]] = [];
        }

        referencesByTarget[reference[target]].push(reference);
        return referencesByTarget;
      }, {});
      cache.set(req, referencesByTarget);
    }

    return referencesByTarget[record[source ?? 'id']] ?? [];
  };
};

exports.populateReferenceMany = populateReferenceMany;

const populateReferenceManyCount = ({
  fetchAll,
  source = 'id',
  target
}) => {
  const cache = new Cache();
  return async (record, {
    rows,
    req
  }) => {
    let referencesByTarget = cache.get(req);

    if (!referencesByTarget) {
      const references = await fetchAll(rows, req);
      referencesByTarget = references.reduce((referencesByTarget, reference) => {
        if (!referencesByTarget[reference[target]]) {
          referencesByTarget[reference[target]] = [];
        }

        referencesByTarget[reference[target]].push(reference);
        return referencesByTarget;
      }, {});
      cache.set(req, referencesByTarget);
    }

    return referencesByTarget[record[source ?? 'id']]?.length ?? 0;
  };
};

exports.populateReferenceManyCount = populateReferenceManyCount;

const populateReferenceOne = ({
  fetchAll,
  source = 'id',
  target
}) => {
  const getAllReferences = populateReferenceMany({
    fetchAll,
    source,
    target
  });
  return async (record, {
    rows,
    req
  }) => {
    const references = await getAllReferences(record, {
      rows,
      req
    });
    return references[0];
  };
};

exports.populateReferenceOne = populateReferenceOne;
let id = 1;

class Cache {
  constructor() {
    this.id = id;
    id += 1;
  }

  get = req => {
    if (!req.locals?.expressCrudRouter) {
      return undefined;
    }

    return req.locals.expressCrudRouter[this.id];
  };
  set = (req, value) => {
    req = req;

    if (!req.locals) {
      req.locals = {};
    }

    if (!req.locals.expressCrudRouter) {
      req.locals.expressCrudRouter = {};
    }

    req.locals.expressCrudRouter[this.id] = value;
  };
}