Skip to main content

Ahead-of-Time (AOT) Compiler - What Is the Angular Compiler?

What Is the Angular Compiler?
The Angular compiler converts our applications code (HTML and TypeScript) into JavaScript code before browser downloads and runs that code.

The @NgModule metadata plays an important role in guiding the compilation process and also tells the compiler what components to compile for this module and how to link this module with other modules.
The Angular offers two ways to compile our application code-
1.      Just-in-Time (JIT) - JIT compiles our app in the browser at runtime (compiles before running).
2.      Ahead-of-Time (AOT) - AOT compiles our app at build-time (compiles while running).

The JIT compilation is the default when we run the build or serve CLI commands -
ng build
ng serve


The AOT compilation, we append the --aot flags to build or serve CLI commands -
ng build --aot
ng serve --aot


Why we need Compilation in Angular?
We need compilation for achieving a higher level of efficiency, performance improvements, faster rendering and also sometimes detect template errors earlier in our Angular applications.

Why Compile with AOT?
1.      Faster Rendering
2.      Asynchronous Requests
3.      Detect template errors earlier
4.      Smaller Angular frameworks download size
5.      Better Security

What Is the difference between JIT compiler and AOT compiler?
JIT (Just-in-Time) -
1.      JIT compiles our app in the browser at runtime.
2.      Compiles before running
3.      Each file compiled separately
4.      No need to build after changing our app code and it automatically reflects the changes in your browser page
5.      Highly secure
6.      Very suitable for local development

AOT (Ahead-of-Time) -
1.      AOT compiles our app code at build time.
2.      Compiles while running
3.      Compiled by the machine itself, via the command line (Faster)
4.      All code compiled together, inlining HTML/CSS in the scripts
5.      Highly secure
6.      Very suitable for production builds

Angular Compiler Class
class Compiler {
  // Compiles the given NgModule and all of its components
  compileModuleSync<T>(moduleType: Type<T>): NgModuleFactory<T>
 
  //Compiles the given NgModule and all of its components
  compileModuleAsync<T>(moduleType: Type<T>): Promise<NgModuleFactory<T>>

  //creates ComponentFactories for all components
  compileModuleAndAllComponentsSync<T>(moduleType: Type<T>): ModuleWithComponentFactories<T>

  ////creates ComponentFactories for all components
  compileModuleAndAllComponentsAsync<T>(moduleType: Type<T>): Promise<ModuleWithComponentFactories<T>>
 
  //Clears all caches.
  clearCache(): void

  //Clears the cache for the given component/ngModule.
  clearCacheFor(type: Type<any>)
}

I hope you are enjoying with this post! Please share with you friends. Thank you!!
By Anil Singh | Rating of this article (*****)

Popular posts from this blog

nullinjectorerror no provider for httpclient angular 17

In Angular 17 where the standalone true option is set by default, the app.config.ts file is generated in src/app/ and provideHttpClient(). We can be added to the list of providers in app.config.ts Step 1:   To provide HttpClient in a standalone app we could do this in the app.config.ts file, app.config.ts: import { ApplicationConfig } from '@angular/core'; import { provideRouter } from '@angular/router'; import { routes } from './app.routes'; import { provideClientHydration } from '@angular/platform-browser'; //This (provideHttpClient) will help us to resolve the issue  import {provideHttpClient} from '@angular/common/http'; export const appConfig: ApplicationConfig = {   providers: [ provideRouter(routes),  provideClientHydration(), provideHttpClient ()      ] }; The appConfig const is used in the main.ts file, see the code, main.ts : import { bootstrapApplication } from '@angular/platform-browser'; import { appConfig } from ...

List of Countries, Nationalities and their Code In Excel File

Download JSON file for this List - Click on JSON file    Countries List, Nationalities and Code Excel ID Country Country Code Nationality Person 1 UNITED KINGDOM GB British a Briton 2 ARGENTINA AR Argentinian an Argentinian 3 AUSTRALIA AU Australian an Australian 4 BAHAMAS BS Bahamian a Bahamian 5 BELGIUM BE Belgian a Belgian 6 BRAZIL BR Brazilian a Brazilian 7 CANADA CA Canadian a Canadian 8 CHINA CN Chinese a Chinese 9 COLOMBIA CO Colombian a Colombian 10 CUBA CU Cuban a Cuban 11 DOMINICAN REPUBLIC DO Dominican a Dominican 12 ECUADOR EC Ecuadorean an Ecuadorean 13 EL SALVA...

39 Best Object Oriented JavaScript Interview Questions and Answers

Most Popular 37 Key Questions for JavaScript Interviews. What is Object in JavaScript? What is the Prototype object in JavaScript and how it is used? What is "this"? What is its value? Explain why "self" is needed instead of "this". What is a Closure and why are they so useful to us? Explain how to write class methods vs. instance methods. Can you explain the difference between == and ===? Can you explain the difference between call and apply? Explain why Asynchronous code is important in JavaScript? Can you please tell me a story about JavaScript performance problems? Tell me your JavaScript Naming Convention? How do you define a class and its constructor? What is Hoisted in JavaScript? What is function overloadin...

25 Best Vue.js 2 Interview Questions and Answers

What Is Vue.js? The Vue.js is a progressive JavaScript framework and used to building the interactive user interfaces and also it’s focused on the view layer only (front end). The Vue.js is easy to integrate with other libraries and others existing projects. Vue.js is very popular for Single Page Applications developments. The Vue.js is lighter, smaller in size and so faster. It also supports the MVVM ( Model-View-ViewModel ) pattern. The Vue.js is supporting to multiple Components and libraries like - ü   Tables and data grids ü   Notifications ü   Loader ü   Calendar ü   Display time, date and age ü   Progress Bar ü   Tooltip ü   Overlay ü   Icons ü   Menu ü   Charts ü   Map ü   Pdf viewer ü   And so on The Vue.js was developed by “ Evan You ”, an Ex Google software engineer. The latest version is Vue.js 2. The Vue.js 2 is very similar to Angular because Evan ...

React | Encryption and Decryption Data/Text using CryptoJs

To encrypt and decrypt data, simply use encrypt () and decrypt () function from an instance of crypto-js. Node.js (Install) Requirements: 1.       Node.js 2.       npm (Node.js package manager) 3.       npm install crypto-js npm   install   crypto - js Usage - Step 1 - Import var   CryptoJS  =  require ( "crypto-js" ); Step 2 - Encrypt    // Encrypt    var   ciphertext  =  CryptoJS . AES . encrypt ( JSON . stringify ( data ),  'my-secret-key@123' ). toString (); Step 3 -Decrypt    // Decrypt    var   bytes  =  CryptoJS . AES . decrypt ( ciphertext ,  'my-secret-key@123' );    var   decryptedData  =  JSON . parse ( bytes . toString ( CryptoJS . enc . Utf8 )); As an Example,   import   React   from ...