Is Angular.js or Ember.js the better choice for JavaScript frameworks?

A lot has changed since the early days of the web when a website would make a single request to the server, which would respond with the entire webpage to be displayed. Back then, the client-side of an application was a paper-thin veneer of HTML, query parameters, cookies, and request headers—and servers did all the heavy lifting.

It’s a very different story today. The front-end of modern websites is now complex enough to handle much of the magic that allows single page applications (SPAs) to deliver the sleek “desktop-like” user experiences that make them so popular. In this article, we’ll look at two of the most popular JavaScript frameworks available for building SPAs—AngularJS and Ember. Both are open-source frameworks based on the model view controller (MVC) design pattern that use wildly different design philosophies to achieve their goals.

AngularJS is a comprehensive, open-source JavaScript framework that solves the problem of developing SPAs by extending the functionality of HTML with directives. AngularJS famously describes itself as “what HTML would have been, had it been designed for building web apps.” The framework places an emphasis on simple modular code and test-driven development.

Some of the key technical features that differentiate AngularJS from Ember are:

• Simplified syntax by using vanilla JavaScript objects for models
• DOM-based templating with directives
• Dependency injection
• More flexible opinionation

AngularJS places an emphasis on getting your app up and running quickly. It opts for syntactic simplicity by using JavaScript objects for models. However, this comes with the performance tradeoff of relying on “dirty checking,” in which a deep comparison on all models within the view must be performed.

Ember combines proven concepts from native frameworks like Apple’s Cocoa with the lightweight sensibilities of open-source frameworks like Ruby on Rails and Backbone.js to create an open-source JavaScript framework that can scale with an entrepreneur’s ambitions. Like AngularJS, Ember is a full-featured framework that specializes in making dynamic, beautifully rendered SPAs. Let’s take a look at some of the key factors that differentiate Ember from AngularJS:

• Avoids “dirty checking” by using accessors
• String-based templating system with Handlebars
• High degree of opinionation
• More powerful routing at the expense of added complexity

Ember emphasizes scalability—it’s meant for apps that plan to scale into much bigger projects, and like a concerned parent, it enforces stricter rules on how you write your code to ensure that your application avoids bottlenecks and is primed for growth.

Both AngularJS and Ember serve a similar singular purpose—to make the development of dynamic SPAs with engaging UI/UX faster and easier for the developer. That means both offer perks like two-way data binding, DOM manipulation, easy unit testing, modular code, and the benefits of the MVC architecture. Where they differ is in their design philosophies and goals.

• String-based templates can be pre-compiled on the server. This signficantly reduces startup time (because there is effectively no computation required at app boot) and means that rendering a template is as simple as invoking a function.
• Angular requires you to traverse the entire DOM at app boot time. The bigger your app is, the slower it starts.
• If you ever want to render your app on the server (for indexing by Google crawlers or to make first loads display faster), Angular requires you to boot an entire browser environment like PhantomJS, which is resource-intensive. Handlebars is 100% JavaScript strings so all you need is something like node.js or Rhino.
• String templates are easy to divide up and load lazily, if your app starts getting large.

• Ember.js makes it extremely easy to create computed properties in JavaScript, which can contain arbitrary expressions. We just require you to specify your dependencies so that we can be smart about when we update. Only things that change are updated.
• Angular must recompute those expressions every time something changes, which means the more bound elements in your app, the slower it gets.
• Because Ember.js only allows you to bind to properties, we will very easily be able to take advantage of the performance benefits of ECMAScript 6 features like Object.observes (http://wiki.ecmascript.org/doku....). Because Angular invented their own subset of JavaScript with a custom parser (https://github.com/angular/angul...), it would be difficult to allow browsers to optimize this in native code.

• With dirty checking, you don't need to use accessors. You can say person.name = "Bill" instead of person.set('name', "Bill") like you would in Ember.js or Backbone.js.
• Why would you ever have so many objects in DOM that this would end up becoming a bottleneck?

• Ember.js Guides
• Rey Bango's Getting Into Ember.js tutorial
• Slides from Luke Melia's talk Introduction to Ember.js at the Ember NYC meetup

<path id="{|unbound guid|}-bars"   
  {|bindAttr d="barsPath"|}    
clip-path="url(#{|unbound guid|}-bars-clip)"    
transform="translate(0,1) translate(1,2)" />

Ember.js was named the best JS framework in 2015. It is used by companies such as Nordstrom, LinkedIn, and Netflix.

Angular.js is popular because it gives developers the best conditions for combining JavaScript with HTML and CSS.

Top 10 Best JavaScript Frameworks List in 2017