ES6 Single Page App

Synopsis

ES6 single page application boilerplate without a framework.

Motivation

Right now, many developers are just curious about ES6 and how it fits into a SPA. The author recommends that they map their knowledge about ES5 object prototypes to ES6 class syntax concepts before trying to reap the benefits of modern rich web app. This approach is relatively new and therefore does not have many great technical references available yet. Many have begun applying this architecture principles to the development of complex web applications and are rapidly building a solid set of best practices based on real world experiences. A solid set of best practices will minimise the effords needed to build an ES6 SPA, while also helping developers identify anti-patterns. This project highlights several best practices that should point out the path to rich client application development.

Application Logic and Implementations

When an url is entered in the browser a request is made to the server side. The request is then received by an ExpressJS application, which fetches data from a database (in our MongoDB) and uses template engine to build the whole page. At runtime, the template engine replaces variables in a template file with actual values derived from the database, and transforms the template into an html content sent to the client. Express ES6 template engine is chosen for this project as it is a simple and extemely fast ExpressJS middleware which uses pure ES6 Javascript syntax. The user gets the html response, while the browser downloads the application modules asynchronously. Now that we have the first page loaded in the browser, we navigate to another one by clicking a link. Here is the catch: this same request is processed differently if instead of entering the page in the address bar, we navigate to a page by clicking a link once the web application is loaded. Javascript intercepts the click event and stops its propagation by preventing the default behaviour. An ajax request is made to ExpressJS to fetch the view content (not the whole page) and return it either as a template string or part of JSON object proceesed by the client side. If the response doesn't require template rendering static content from a CDN source is fetched instead. The main difference between is that when we request static resources the request does not hit our ExpressJS application.

Features

1. ES6 class inheritance

Flexible single page app architecture based on ES6 rigid class inheritance hierarchies allows extension of the traditional request response model the classic web is built upon. Single Page architecture built upon ES6 class inheritance enables createtion of new classes that reuse, extend, and modify the behavior that is defined in other classes. The architecture also relies heavily upon ES6 module loader to pass information to and from the server to the client to merge with views that present data. This approach provides much less network activity, faster responses to user interactions and smaller server loads.

2. Secure token based authentication

Successful token authentication system requires us to have detailed knowledge of security vulnerabilities and possible pitfalls associated with them. Single page app tend to have a complex structure: logged in view, the logged out view, or the restricted view. A basic example of this is when a user navigates to an app home address, based on if he is logged in or not, he is served with an account or login view content under the same url. It all comes down to access control. Users get the same app but they may not have the same levels of access. Csurf REST API session tokens presented in this app are great authentication mechanism with a solid secure layer that help us define who a user is and what they can access.

3. Isomorphic application logic that allows the same snippets of code to run both in the server and the client

The process described above illustrates concept of isomorphic application which is usually sold as a high performance solution for loading time in single page applications. It allows the same logic to applied both in the server and the client and gracefully extends SPA concept. A SPA that does not render on the server (isn’t isomorphic) doesn’t just degrade when javascript doesn’t work, it’s totally broken. This leads us to the conclusion that isomorphic javascript is just progressive enhancement done the proper way. We always serve up a usable page with core level functionality, while progressively enhancing with javascript. Search crawler receives the full page as well as a regular user. The whole state of the application is restored from URL. Only a single page is requested from the server on the initial load and all other subsequent views (similar to traditional pages) are taken in and out of view as needed. Below is a step-by-step list of how this requests was processed:

Prerequisites

• MongoDB - Download and Install MongoDB - Since this project is scaffolded with mongoose, we need mongoDB to be installed and have the mongod process running.

Installation

Once you have forked this project, go ahead and use npm through the command line to install all required dependecies:

npm install

Next we use jspm to install Babel transpilation in the browser and in builds. To do this we enter /src folder and execute the following:

jspm install