If you're looking to upgrade your AngularJS application to modern-day web development standards, it helps to know what is the right approach and the right tools to use. In this article, I will explain the differences between AngularJS and Angular. Then, I will explain why you need to migrate your project from AngularJS to Angular and then describe the migration tools available to make your life easier.
What is AngularJS?
AngularJS is a web and mobile application framework used to develop Single-page applications. This framework was developed by Google engineers and is based on the Model-View-Controller.
The MVC architecture comprises;
Model -- The data structure that organizes data inputs from the controller.
View -- The view displays raw data and information.
Controller -- The controller handles instructions and interactions within the data model.
The first version of AngularJS was released in 2012. As time progressed, new updated versions were launched. However, as more versions were released over the years, a major rewrite was done that resulted in Angular 2.
To eliminate naming confusion, the Angular team decide that AngularJS would refer to any version between Angular 1.x to Angular 2. All versions above Angular 2.0 would simply be called Angular.
Why should you opt for Angular?
After its release in 2012, AngularJS gained in popularity. Initially, small-scale developers were the main customers. Later, bigger software developing companies started using AngularJS for large-scale purposes. At this point, developers started experiencing performance issues. In an interview in 2018, Stephen Fluin; a Google Angular engineer observed that AngularJS was not built for large-scale usage.
"There were millions of AngularJS developers and millions of AngularJS apps. The cracks started showing. If you wrote an AngularJS app the wrong way and had thousands of things on the screen, it ended up getting very slow. The architecture was just not designed with this kind of large-scale usage in mind."
After Angular 2, it was evident that Google has adopted a revolutionary approach and as a result, there are efforts to encourage developers to migrate from AngularJS to Angular.
Difference between AngularJS and Angular
The majority of front-end developers are familiar with the angular framework. With the different versions, developers must determine which angular version to use for their project.
So, which Angular version is better and why?
The section below illustrates the difference between AngularJS and Angular.
| Difference | AngularJS | Angular |
|---|---|---|
| Script | It is based on JavaScript | It is based on TypeScript. TypeScript is a superset of ECMAScript 6. typescript enjoys the benefits of ES6 like Lambda operators and Iterators. |
| Controllers vs Components | It enables developers to scope variables visible in both view and controller. It also supports rootScope where created variables are globally available. | It does not support scope or controller concepts. However, its main architectural concept is the hierarchy of components. |
| Template engine | Has many directives and allows developers the liberty to specify custom directives. | It has standard directives that are implemented differently. |
| Expression syntax | AngualrJS has both the ng-model and ng-bind. Ng-model implements two-way binding while ng-bind implements one-way binding. | Angular has only the ng-model. "[ ]" is used to implement one-way binding while "[( )]" is used to implement two-way binding. "( )" is used for event binding while "[ ]" is used in event binding. |
| Architecture | It is based on the Model-View-Controller. The MVC model organizes data logic, exhibits application behavior, and stipulates the rules. The View *relays output information from the *model. *The *controller *transforms inputs into commands and then sends them to the *view *and the *model. | It uses components and directives instead of controllers and scope. The components and directives handle the application's view and the page logic. Angular 2 has structural directives that transform the DOM layout and attributive directives that transform the DOM element appearance. |
| Mobile support | Supports web applications | Supports both web and mobile applications |
| Routing | Uses $routeprovider.when() for routing configuration. | Uses @RouteConfig{(...)} for routing configuration. |
| Performance | Has limited performance because it was meant for designers. | Has enhanced high-speed performance because it is built for designers and developers. |
| Dependency Injection | Does not support dependency injection | Supports hierarchical dependency injection with unidirectional tree-based change detection. |
| Structure | It is complex and difficult to manage | Has better structures making it easy to manage |
Pros and Cons: Which version of Angular is best for you?
Angular JS
Advantages
- Facilitates faster application development due to excellent MVC data binding.
- Angular JS has comprehensive resources such as plugins sufficient for front-end developers. Developers do not need to use other frameworks.
- Angular JS is very intuitive because it utilizes HTML as a declarative language.
- Angular JS is very flexible as it can develop both iOS and Android applications.
Disadvantages
- Angular JS has multiple ways of achieving the same thing making it complex and difficult to use.
- It has poor scalability
- It has performance issues when handling many requests.
Angular 2
Advantages
- The use of TypeScript enhances code optimization
- Angular 2 supports mobile-oriented applications
- Enhances dependency injection
- Avails varying scripting languages like ES6, ES5, and TypeScript.
- Facilitates code routing.
Disadvantages
- It has a complex setup process compared to Angular JS.
- It is not viable for small and simple web applications.
Angular 4
Advantages
- Enhances quick application development by providing templates.
- It is suitable when developing single-page web apps.
- TypeScript assists in developing bulky apps.
- It is easy to write and test codes by providing a framework that accommodates unit system testing.
- Angular provides templates that allow developers to produce clean codes.
- It has a modular animation package.
- Angular produces applications that are compatible with both mobile and desktop.
Disadvantages
- It is slow when outputting large amounts of data.
Why should I migrate to Angular?
Before making the great move there are questions you should ask yourself, what benefits will I get from the new framework? Migrating from one developer framework is not an easy decision to make but a careful evaluation of the framework you are migrating to gives a clear picture of the benefits it comes with.
Angular, being an evolution of AngularJS, is better than its predecessor in creating better user interfaces. These are the reasons you should migrate your apps to Angular.
Flexible Architecture
The architecture of Angular is based on a hierarchy of services and components, a feature that was not present in AngularJS. The hierarchical nature allows the elements to be reusable and makes it easier to test and maintain them.
Availability of Ready to use Angular Resources
Wrappixel Angular Mega Bundle
AngularJS and Angular are open source and thus receive massive support from Google engineers and the developer community. At WrapPixel, we love the Angular framework and our community of developers has curated a master list of ready-to-use Angular Themes, Angular Dashboards, Angular Website Templates, and* Angular Control Admin panels *to help developers looking to migrate to the latest version of Angular.
If you're an agency or a product development company looking to create multiple Angular Web apps or Admin Panels, the Angular Mega Bundle is a must resource. It comes with more than 60 plugins, 1000s of Angular UI Components and pages, unique* Angular Dashboards, and 7+ Angular templates*. The templates, clean documentation, and dedicated support make Angular app development a breeze, even for novice developers.
Handheld device Support
AngularJS does not support the development of handheld device apps. With the rapid increase in popularity of mobile device usage, you should consider migrating to Angular, which will enable you to develop mobile apps. Angular version 2 and the following versions offer mobile app support across all devices. They have features such as touch support, performance tuning, and low memory utilization among others, which are useful in solving mobile-related issues. Angular 7 has a modular design that significantly reduces the memory footprint on mobile devices.
Improved Speed<
With AngularJS, the code tends to be slower when running large applications due to a large number of scopes and bindings. The two-way binding causes delays and bottlenecks.
In Angular 2 and above, there was the introduction of property binding, event binding, and template binding, all of which improve the performance of the app. Angular 6 uses a rendering engine called Ivy which introduces faster compilation, smaller-sized bundles, faster debugging, and increased flexibility.
Better Structure
AngularJS is flexible but has low stability and manageability. Angular, having a component-based approach, has a precise way of exchange of data among the components. This will make it easier for you to seamlessly create and maintain large apps.
Angular allows the use of modules. The module allows the separation of code into smaller units depending on the use. This makes it easier to understand where different elements are located. You can create different modules such as login, user setting, and shared components, each of which will import the required libraries and components.
Modules coupled with lazy loading create smaller pieces of code that are only loaded by the browser only when needed. This makes load time faster by showing you what is needed at that time.
Consistency and flexibility
AngularJS is written in plain JavaScript which lacks type-checking features making compile-time errors. Angular is written in TypeScript which offers consistency and flexibility. Since TypeScript is a superset of JavaScript, you will have an easy time since the syntax and approach is similar to what you already know. Typescript reduces runtime errors as they are recognizable before compilation takes place.
Material Design
In Angular 5, the component design kit (CDK), the core of the Angular Material component library, also facilitates the development teams to create their elements. This element allows the creation of applications that are responsive and can run on different platforms. Additionally, the material design helps in developing an improved user interface.
Regular Updates
The angular development team provides regular updates to give your apps maximum stability. This also includes security patches that allow a secure development platform for secure applications devoid of vulnerabilities. The Angular development team uses a time-based publishing cycle and therefore they can release new and improved versions after every six months.
There are many substantial benefits of migrating from AngularJS to Angular. Angular generally will improve your experience through new features and this makes it worth migrating to.
Tools for migrating from Angular JS to Angular
Migration to Angular has been made easy by using these two tools; ngMigration Assistant and ngMigration Forum. These tools are meant to provide a correct migration process, by avoiding possible mistakes.
ngMigration Assistant
This is an analysis tool that is very easy to use. It uses a command line interface (CLI) with simple instructions to follow. ngAssistant analyses the AngularJS application and gives a suitable recommendation on how to move your app to Angular. In other words, ngMigration helps to determine the best path to use when migrating from AngularJS to Angular.
ngMigration assistant provides a good starting point when you decide to migrate your project to Angular. When you run the tool, it analyses the code base and provides details on the size of the code, the complexity, and the patterns used in the project. With this, the tool proposes the path to follow and provides instructions for you to follow in the preparation for the migration as shown below.
The main objective of ngMigration Assistant is to give you simple, clear, and constructive guidance on how to migrate your app or project. ngMigration Assistant can be used for any size of the app, whether big or small. Not all possibilities are taken into consideration, only the size of the code and its complexity.
Installing the ngMigration assistant is also an easy task.
Install globally, whether using npm or yarn using these commands
After a successful installation, run the program and it will scan the working or input directory, as shown in the command below
From that point, the tool will start scanning the app and provide you with the necessary recommendations and steps to follow to migrate your app.
ngMigration Forum
This is a community hub composed of developers, users, and entrepreneurs who discuss and share information on the best way to migrate from AngularJS to Angular. This forum will provide you with a good starting point and the steps to take when conducting the migration.
From the forum, your migration questions will be expertly answered, useful tools identified and you will be directed to a migration solution. Also, you will learn, discuss and share information about the migration to Angular.
The forum provides arrays of useful information, such as the importance of migrating to Angular from a technical and business perspective and an overview of the migration paths that you can use.
In the Forum you will find many migration paths consolidated over time and many useful tools that help throughout the migration process.
In-depth information is provided on all the migration paths where you can learn how they work, tools that will help you, examples, and read any helpful content. There are also experts to help you with the path you decide to use, throughout the migration process.
The community works together to share its expertise and experience in the migration process. You are also encouraged to contribute to the forum and give helpful insights, and tools, ask questions or provide answers about the migrations.
Migration approaches
Before migrating from Angular JS to Angular, it is good for developers to strategize how to migrate. A good migration strategy makes the migration process smooth and easy.
Angular complete rewrite
One migration strategy adopted by developers is the incremental approach. The incremental approach is suitable in incidences where the application is too large and might consume a lot of time during the migration process. This means that continuous support is needed for the application when migrating from Angular JS to Angular.
However, in instances where the application is small and can be migrated over a short time, then a complete rewrite is the better approach.
A complete rewrite involves migrating an application to Angular without supporting the previous Angular JS version.
The migration approach selected relies on your objectives as a developer or as an entrepreneur. On several occasions, business requires their applications to continue running without interruptions.
When migrating large applications, organizations should also consider splitting the applications across teams where each team migrates each section at different times.
Despite the migration tools available, migrating a project from AngularJS to Angular is not an easy process.
The section below describes Angular upgrade modules;
Module loader
Developers can employ the available module loaders such as SystemJS, Webpack, or Browserify to upgrade their projects.
For a developer, you can break down your application code into individual file components. This helps you organize your large project into small structured files.
Loading all these files with an <script> into an HTML page is hectic and sometimes does not work efficiently.
To avoid these hectic processes, it is good to employ a module loader. Module loaders like Webpack allow you to utilize the import and export features. These features specify which code should be shared between various application parts. The CommonJS module loader enables users to use the required module.exports features.
Migration to TypeScript
Angular uses TypeScript instead of JavaScript. When migrating applications from AngularJS to Angular, it is good to load the TypeScript compiler.
Loading the TypeScript compiler helps you to stop worrying about how to implement Typescript. It also helps you to start utilizing TypeScript in your loaded AngularJS code.
Using component Directives
In Angular, components provide the basis for building user interfaces. The various user Interface portions are categorized as components and then transformed into the expected user experience.
AngularJS applications implemented using Component directives are easier to migrate than applications developed using inferior features like* ng-controller and ng-include.*
Before migrating AngularJS to Angular, ensure that your AngularJS component directives have the following attributes;
- Restrict: 'E' components that are utilized as elements.
- Scope: {} is an isolate scope. Angular implements isolation and therefore, ensure your AngularJS components are also isolated to enhance compatibility.
- bindToController: {} ensure components are bound to controller instead of $scope.
- controller and controllerAs
- template or templateUrl
The snippet below illustrates an AngularJS component directive that is fully compatible with the Angular architecture.
If your component directives are not compatible with Angular, it is good to use component API to help you define the components easily.
Migrating using ngUpgrade
The ngUpgrade helps you compare AngularJs and Angular components in an app and combine them to operate seamlessly. The ngUpgrade allows you to conduct the migration in bits since the different frameworks coexist together.
ngUpgrade has a Upgrademodule that helps you bootstrap and organizes your hybrid applications. According to the AngularUpgrade Guide,
"When you use ngUpgrade, what you're doing is running both AngularJS and Angular at the same time. All Angular code is running in the Angular framework, and AngularJS code in the AngularJS framework."
Bonus Tip: Must Have Resources for Angular development
As a developer or an entrepreneur, migrating from AngularJS to Angular is essential. Migrating will help you enjoy increased flexibility and scalability.
If you're concerned about the number of manhours and development effort involved in building an Angular app, we have developed a wide range of Angular Templates and* Angular Resources *for you to choose from. These Angular templates will help save development time and avoid the high cost of developing everything from scratch.
Our Angular Templates are trusted by thousands of customers all over the world. When you purchase our templates, you enjoy free support, a wide range of plugins, multiple admin dashboards, and seamless functionality.
If you feel that we've missed out on any Angular Hacks that can help make life easier for developers, please share in the comments, we'd love to hear from you.
If you are looking to hire angular developers, here is a complete guide from Toptal.
If you are looking for Free Angular Templates then check out the below article:
Top comments (1)
AngularJS does support dependency injection.