Example client-side requirejs module for locally caching REST data. Uses Durandal (durandaljs.com), Knockout, and Knockout Persist plugin (https://github.com/spoike/knockout.persist)

Meetings.js

define(function () {
    var $ = require('jquery');
    var http = require('plugins/http'); // Durandal plugin
    var instance = null;
    var ko = require('knockout');

    function Meetings(maxAge) {
        if (instance !== null) {
            throw new Error("Cannot instantiate more than one Meetings, use Meetings.getInstance()");
        }
        var self = this;
        // Default expiration of 1 hour if undefined:
        self.maxAge = maxAge || 60 * 60 * 1000;

        self.meetings = ko.observableArray().extend({
            persist: 'meetings' // LocalStorage plugin
        });

        self.lastRefresh = ko.observable(0).extend({
            persist: 'lastRefresh' // LocalStorage plugin
        });

        self.refresh = function () {
            return http.get('/api/me/meetings') // Local REST API
                .then(function (meetings) {
                    self.meetings = meetings;
                    self.lastRefresh(new Date().getTime());
                });
                // Auth errors are exposed in getMeetings promise fail
        }

        self.cacheExpired = function() {
            return new Date().getTime() - self.lastRefresh() > self.maxAge;
        }

        // Gets Meeting list, which may be cached
        self.getMeetings = function () {
            var deferred = $.Deferred();
            
            if (self.cacheExpired()) {
                console.log('Cache Miss');
                self.refresh()
                    .then(function () {
                        deferred.resolve(self.meetings);
                    })
                    .fail(function (err) {
                        deferred.reject(err);
                    })
            } else {
                console.log('Cache Hit');
                deferred.resolve(self.meetings);
            }

            return deferred.promise();
        }

        // Creates Meeting and expires cache
        self.scheduleMeeting = function() {
            self.lastRefresh(0);
            return http.post('/api/me/meetings');
        }
    }

    Meetings.getInstance = function () {
        if (instance === null) {
            instance = new Meetings();
            instance.refresh();
        }
        return instance;
    };

    return Meetings.getInstance();
});