Source: model-any-changed-attribute-listener.js

/*
 * Copyright 2016-2017 Hewlett Packard Enterprise Development Company, L.P.
 * Licensed under the MIT License (the "License"); you may not use this file except in compliance with the License.
 */

/**
 * @module js-whatever/js/model-any-changed-attribute-listener
 */
define([
    'underscore'
], function(_) {
    'use strict';

    /**
     * @alias module:js-whatever/js/model-any-changed-attribute-listener
     * @desc Listen to change events on the given model, calling the callback if one of the given attributes has
     * changed. The callback is called with standard Backbone change event arguments in the context of the listener.
     * @param {Backbone.Events} listener
     * @param {Backbone.Model} model
     * @param {String[]} attributes
     * @param {Function} callback
     * @returns {Function} The change callback added as a listener on the model; useful for removing the callback later
     */
    function addChangeListener(listener, model, attributes, callback) {
        var inTargetAttributes = _.partial(_.contains, attributes);

        function changeCallback() {
            var changedAttributes = _.keys(model.changedAttributes());

            if(_.any(changedAttributes, inTargetAttributes)) {
                callback.apply(listener, arguments);
            }
        }

        listener.listenTo(model, 'change', changeCallback);
        return changeCallback;
    }

    return addChangeListener;
});