data-provider-temporary/examples/node_modules/data-provider/dist/DataProvider.js

Library that helps with server-to-client synchronization of data

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _lodash = require('lodash');

var _lodash2 = _interopRequireDefault(_lodash);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

class DataProvider {
  constructor({ id, ref, rawOnData, onData, initialData }) {
    this.id = id;
    this.ref = ref;
    this.rawOnData = rawOnData;
    this.onData = onData;
    this.userConfigs = {};
    this.loaded = false;

    if (initialData !== undefined) {
      this.loaded = true;
      this.onData(initialData);
    }
  }

  updateUser(userId, { polling = Infinity, needed = true, rawGetData, getData }) {
    let needFetch = false;

    if (rawGetData != null && !_lodash2.default.isEqual(rawGetData, this.rawGetData)) {
      needFetch = true;
      this.rawGetData = rawGetData;
      this.getData = getData;
      this.loaded = false;
    }

    let oldPolling = this.polling();
    this.userConfigs[userId] = { polling, needed };

    if (this.polling() < oldPolling) {
      needFetch = true;
    }

    if (!this.loaded && !this.timer) {
      needFetch = true;
    }

    if (needFetch) {
      this.fetch();
    }
  }

  removeUser(userId) {
    delete this.userConfigs[userId];
  }

  polling() {
    return _lodash2.default.min([..._lodash2.default.values(this.userConfigs).map(({ polling }) => polling), Infinity]);
  }

  needed() {
    return _lodash2.default.reduce(_lodash2.default.values(this.userConfigs).map(({ needed }) => needed), (v1, v2) => v1 || v2, false);
  }

  canceled() {
    return _lodash2.default.isEmpty(this.userConfigs);
  }

  scheduleNextFetch() {
    if (this.polling() === Infinity) {
      return;
    }

    this.timer = setTimeout(() => {
      this.fetch();
    }, this.polling());
  }

  fetch() {
    if (this.canceled()) {
      return null;
    }
    if (this.timer) {
      clearTimeout(this.timer);
    }

    return this.getData().then(data => {
      if (!this.canceled()) {
        this.loaded = true;
        this.onData(data);
      }
    }).catch(e => {
      console.error(e); // eslint-disable-line no-console
    }).then(() => this.scheduleNextFetch());
  }
}
exports.default = DataProvider;