Aurelia Vs AngularJS : Which One To Choose?

In the web development world and javascript world, we’ve seen a lot of paradigms come and go. But one paradigm has stuck around: the single-page web application. AngularJS is one of the most popular frameworks backed by Google, and it offers quick, easy development of rich, client-side applications by the use of declarative two-way data binding. AngularJS is used by popular companies like Amazon and Pluralsight. 

Whereas, the Aurelia framework was released a couple months prior to Angular 2, and also serves as a great choice of SPA framework with a quickly growing audience. Aurelia, has become a popular choice for rich, client-side applications. Aurelia targets the same problem space as AngularJS. However, Aurelia uses a modern approach to ease development and solve a lot of the problems that plagued AngularJS.  

So What’s the difference between Aurelia and Angular? Before starting comparison, let us see What is Angular and What is Aurelia?

Aurelia-

Aurelia was backed by Durandal Inc and was licensed under the MIT license. It is an open-source framework and provides great rendering speed, very good memory efficiency, unidirectional data flow which is safer, higher standards of compliance, greater integration compatibility with different other platforms or frameworks. Deloitte, Chegg, dev and many such popular companies make use of Aurelia. Here are some of the features of Aurelia-

• Broad Language Support
• Two-Way Databinding
• Routing & UI Composition
• Testable

Angular-

AngularJS is a front-end web framework supported by Google. This framework makes use of HTML as your template language and allows you to extend HTML’s syntax to express app’s components more clearly. Amazon, snapchat, Tinder and many more popular brands uses Angular.js. Let us see features of Angular.

• Templates
• MVC Framework
• Access to the POJO Model
• Unit Testing Facilities

Aurelia vs Angular-

1. MV* Approach-

Aurelia follows the Model-View approach. There is no need to specify the particular controllers of view-models; the naming conventions will do that. For instance-

“AnyFile.html”:  Any file loaded under router-view or called at the time of instantiating Aurelia App.
 <template>
 <!-- HTML and Aurelia(Model) code goes here -->
 </template>
 “AnyFile.js”: Controller of the Anyfile.html view-model.
 export class AnyFile {
 constructor() {
} 
}

When comparing with Angular, you will see the difference in watching MV* components. One of the big disadvantage of AngularJS is that it has a very sheer learning curve. You must know its internals, the complete digest cycle pretty well and have to know the effect on performance while using $watch expressions and filters. Whereas Aurelia is simple and has a smooth learning curve.

2. Language Support-

API’s of Aurelia are deliberately designed to be employed naturally from today’s and tomorrow’s useful web programming languages.  Aurelia supports Typescript ES2015, ES5, ES2016 and it is very important and gives you high extensibility. Developing web apps by using ES6 is not a new thing. There are some solutions that can allow you to write Angular apps using ES6. 

Aurelia supports for ES6 and Gulpfile with a customized build system to ensure your ES6 down to ES5 compatible code.

3. Data Binding-

Aurelia supports two types of data-binding-

1. One way data binding

2. Two way data binding

Using adaptive techniques, one can choose the most appropriate way to observe each property in your model and automatically synchronize UI with best-in-class performance. For instance-

One way data binding-

<!-- these have the same result -->
<input value.bind="anyValue & oneWay>
<input value.one-way="anyValue">

Two-way Data-Binding:

<!-- these have the same result -->
<input value.bind="anyValue & twoWay>
<input value.two-way="anyValue">

Angular also allows two-way data binding but for beginners it is tough to adopt the Angular way. With a large number of filters, watches, a complex DOM structure etc. you will find performance issues. 

Regardless of a few enhancements are implemented, later on, they are not much effective. Whereas, Aurelia is less complex and easy to learn. There are very less chances of performance issues to implement two-way data binding.

4. Services-

Services of Aurelia and angular are some how similar. If you need NumberOperator that depends on NumberGenerator.

Services in Aurelia-

import {inject} from 'aurelia-framework';
import {NumberGenerator} from './number-generator'
export class NumberGenerator {
  getNumber(){
    return 42;
  }
}
@inject(NumberGenerator)
export class NumberOperator {
  constructor(numberGenerator){
    this.numberGenerator = numberGenerator;
    this.counter = 0;
  }
  getNumber(){
    return this.numberGenerator.getNumber() + this.counter++;
  }
}

For component, we inject the same way:

import {inject} from 'aurelia-framework';
import {NumberOperator} from './_services/number-operator';

@inject(NumberOperator)
export class SomeCustomElement {
  constructor(numberOperator){
    this.numberOperator = numberOperator;
    //this.numberOperator.getNumber();
  }
}

With dependency injection, any class can be completely extensible service. So you can write your own resolvers. 

Factories in Aurelia-

If you want a factory or a new instance, you can do as-

import { Factory, NewInstance } from 'aurelia-framework';
@inject(SomeService)
export class Stuff {
  constructor(someService, config){
    this.someService = someService;
  }
}
@inject(Factory.of(Stuff), NewInstance.of(AnotherService))
export class SomethingUsingStuff {
  constructor(stuffFactory, anotherService){
    this.stuff = stuffFactory(config);
    this.anotherServiceNewInstance = anotherService;
  }
}

Angular Services-

Let us see same set of services in Angular 2:

import { Injectable } from '@angular/core';
import { NumberGenerator } from './number-generator';

@Injectable()
export class NumberGenerator {
  getNumber(){
    return 42;
  }
}
@Injectable()
export class NumberOperator {
  counter : number = 0;
  constructor(@Inject(NumberGenerator) private numberGenerator) { }
  getNumber(){
    return this.numberGenerator.getNumber() + this.counter++;
  }
}

Annotation @Injectable is necessary and to actually inject service, you have to specify the service in the list of providers in the component configuration or the complete module configuration, like so;

@Component({
//...
  providers: [NumberOperator, NumberGenerator]
})

Or, you can also specify it in bootstrap(AppComponent, [NumberGenerator, NumberOperator]) call.

Remember that, you have to specify both NumberOperator and NumberGenerator, instead of how you inject it.

The resulting component will look like-

@Component({
  //...
  providers: [NumberOperator, NumberGenerator],
})
export class SomeComponent {
  constructor(@Inject(NumberOperator) public service){
    //service.getNumber();
  }
}

Factories in Angular-

You can create factories with provide annotation, that is good for aliasing services. 

Factory creation will look like-

let stuffFactory = (someService: SomeService) => {
    return new Stuff(someService);
}
@Component({
  //...
  providers: [provide(Stuff, {useFactory: stuffFactory, deps: [SomeService]})]
})

5.Shadow DOM-

Angular and Aurelia support Shadow DOM.

With Aurelia, just use @useShadowDOM decorator.

import {useShadowDOM} from 'aurelia-framework';
@useShadowDOM()
export class YetAnotherCustomElement {}

With angular, this can be done with ViewEncapsulation.Native:

import { Component, ViewEncapsulation } from '@angular/core';
@Component({
  //...
  encapsulation: ViewEncapsulation.Native,
})
export class YetAnotherComponent {}

6. Extensible HTML-

In Aurelia, extensible HTML compiler allows you to create custom HTML elements. This helps you to add custom attributes to existing elements and control template generation, with support of data-binding, dynamic loading and high-performance batched rendering. Let us see an example:

“AnyParentFile.html”:
 <template>
 <div custom-attribute></div>
 <!-- Custom Element -->
 <child-element></child-element>
 </template>
 “ChildElement.html”: View Model for custom element
 <template>
 <!-- Child element view model code goes here -->
 </template>
 “AnyParentFile.js”: Controller for AnyParentFile
 export class AnyParentFile {
 constructor() {

}
 }
 “ChildElement.js”: Controller for ChildElement
 // Module customElement
 import { customElement } from 'aurelia-framework';
 // create custom element childElement
 @customElement('childElement')
 export class ChildElement {
 constructor() {

}
 }

The time when AngularJS was developed, the standards for extending HTML were not that much developed. So, AngularJS created proprietary solutions for templating and custom elements.

These days, web component specs defines a rules for both custom elements and templating. Aurelia actively connects to these standards, supporting the HTML imports, <template> element, Shadow DOM, and native custom elements.

Wrap up-

These are some of the differences between Aurelia and angular. The selection of a framework depends on the project specification and personal preferences. If you are confused to choose the best one framework for your next project, consult with Solace experts. We are here to help you through consultation and development. It will be better to hire dedicated developers of Solace team who are expert in the framework.