A client-side comparator generating function for Backbone collections

comparatorGenerator.js

/**
 * This method creates a new comparator function that should correctly sort by the right field in the correct order
 * assuming the sorting is specified by a single field with a "attributeName-asc/desc" format. Add as a change handler
 * for your sortBy field, add `this.on('sync', this.sort)` to the collection, and you're ready to go.
 * @param {Backbone.Model} model
 * @param {string} newSortBy
 * @deprecated
 */
updateCollectionComparator: function(model, newSortBy) {
    var theCollection = this.someCollection, // change this line
        parts = newSortBy.split('-'),
        fieldPart = parts[0],
        attrName = fieldPart.charAt(0).toLowerCase() + fieldPart.slice(1),
        dir = parts[1].toLowerCase();

    theCollection.comparator = function (one, two) {
        var oneVal = one.get(attrName),
            oneId = one.id,
            twoVal = two.get(attrName),
            twoId = two.id;

        // If all else is equal, sort by aggregateVersion
        if (oneVal === twoVal) {
            if (oneId === twoId) { return 0; }
            if (dir === 'asc') {
                return oneId < twoId ? -1 : 1;
            } else {
                return oneId > twoId ? -1 : 1;
            }
        }
        if (dir === 'asc') {
            return oneVal < twoVal ? -1 : 1;
        } else {
            return oneVal > twoVal ? -1 : 1;
        }
    };

    this.console.log('Updated event collection to sort %s on %s', dir, attrName);
}