@adobe/adobe-client-data-layer/src/utils/listenerMatch.js

Adobe Client Data Layer

/*
Copyright 2020 Adobe. All rights reserved.
This file is licensed to you under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License. You may obtain a copy
of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under
the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
OF ANY KIND, either express or implied. See the License for the specific language
governing permissions and limitations under the License.
*/

const _ = require('../../custom-lodash');
const has = _.has;

const CONSTANTS = require('../constants');
const ancestorRemoved = require('./ancestorRemoved');

/**
 * Checks if the listener matches the item.
 *
 * @param {Listener} listener The listener.
 * @param {Item} item The item.
 * @returns {Boolean} true if listener matches the item, false otherwise.
 */
function listenerMatch(listener, item) {
  const event = listener.event;
  const itemConfig = item.config;
  let matches = false;

  if (item.type === CONSTANTS.itemType.DATA) {
    if (event === CONSTANTS.dataLayerEvent.CHANGE) {
      matches = selectorMatches(listener, item);
    }
  } else if (item.type === CONSTANTS.itemType.EVENT) {
    if (event === CONSTANTS.dataLayerEvent.EVENT || event === itemConfig.event) {
      matches = selectorMatches(listener, item);
    }
    if (item.data && event === CONSTANTS.dataLayerEvent.CHANGE) {
      matches = selectorMatches(listener, item);
    }
  }

  return matches;
}

/**
 * Checks if a listener has a selector that points to an object in the data payload of an item.
 *
 * @param {Listener} listener The listener to extract the selector from.
 * @param {Item} item The item.
 * @returns {Boolean} true if a selector is not provided or if the given selector is matching, false otherwise.
 * @private
 */
function selectorMatches(listener, item) {
  if (item.data && listener.path) {
    return has(item.data, listener.path) || ancestorRemoved(item.data, listener.path);
  }

  return true;
}

module.exports = listenerMatch;