Angular is a TypeScript-based framework designed for building scalable web applications. Angular is the preferred platform for web developers, it offers numerous benefits, including the ability to create reusable custom components, a straightforward CLI, server-side rendering with Angular Universal, and robust support from Google.
In this blog, we will learn about how you can optimize your Angular Apps effectively.
Why Optimize Angular Apps?
While Angular simplifies frontend development, it’s not without its challenges. Complex Angular applications can become sluggish, especially if not developed with best practices in mind.
Unlike React, Angular has a steeper learning curve and a more rigid structure. However, when used correctly, Angular can power high-performance applications, making optimization crucial.
If done right, Angular can be an advantageous framework that facilitates the development of highly performant apps. Therefore it is necessary to Optimize Angular Apps.
The Solution: Optimization
Optimization is a standard solution to angular performance tuning. The optimization involves altering your application’s code for better performance and easier maintenance.
One common misconception is that optimization begins after your application has been deployed. The process should start right when you start writing your code; otherwise, it becomes harder to reverse mistakes.
Likewise, you need to optimize angular apps for the clean execution it promises. To aid your next project in angular, we’ve compiled an Angular app optimization checklist, which can help improve performance of angular apps.
Read more on Optimization: Your Ultimate Guide To Build SEO-Friendly Angular Websites in 2023
7 Effective Methods to Optimize Angular Apps:
1. AoT Compilation
As mentioned earlier, Angular is based on Typescript. To compile Typescript to JavaScript- there are two modes:
- Just-in-Time Compilation (JIT): This mode compiles during execution. Specifically, the program translates to native code (in this case, JavaScript) only when a function is invoked. While JIT is advantageous for cross-platform development, it has its drawbacks. For instance, rendering larger components can be time-consuming due to on-the-fly compilation.
- Ahead-of-Time Compilation (AoT): AoT compiles during the build phase. This approach eliminates the need for an Angular compiler in the final deployment bundle. The benefits are twofold: it reduces the app’s size and accelerates the rendering of components, leading to enhanced performance.
For optimal Angular app performance, leveraging AoT Compilation is a pivotal step.
2. Change Detection
Change Detection is a mechanism in Angular that monitors and reflects changes in user data within component data. For extensive applications, frequent change detection can impact performance. To enhance this, consider the following strategies:
1. OnPush Change Detection Strategy
By default, Angular checks for changes starting from the root component down to the smallest subtree, which can be inefficient. The OnPush strategy streamlines this by focusing only on specific branches that require change detection, leaving out unnecessary checks on other branches and root components.
| @Component({ selector: ‘app-root’, template: `Number of ticks: {{numberOfTicks}}`, changeDetection: ChangeDetectionStrategy.OnPush, }) class AppComponent { numberOfTicks = 0; constructor(private ref: ChangeDetectorRef) { setInterval(() => { this.numberOfTicks++; // require view to be updated this.ref.markForCheck(); }, 1000); } |
2. Detach Change Detector
Every component in Angular has an associated Change Detector. In applications with numerous components, this can prolong rendering times. A remedy is to detach the Change Detector from select components, ensuring their associated subtrees aren’t unnecessarily checked.
This can be done by calling the class ChangeDetectorRef:
| abstract class ChangeDetectorRef { abstract markForCheck(): void abstract detach(): void abstract detectChanges(): void abstract checkNoChanges(): void abstract reattach(): void } |
3. Using Pure Pipes
Pipes in Angular transform input values within template expressions. There are two categories: pure and impure. Pure pipes, as the name suggests, give consistent output for identical input. In contrast, impure pipes might yield varying results for the same input. By default, pipes are pure.
Leveraging pure pipes ensures change detection activates only when there’s an actual change in value.
| @Pipe({ name: ‘filterPipe’, pure: true }) export class FilterPipe {} |
3. Lazy Loading
Lazy loading is an inherent Angular feature designed to enhance app performance. In intricate applications with multiple feature modules, loading all modules simultaneously during app launch can be resource-intensive, leading to slower performance and increased memory usage.
Instead, lazy loading strategically loads only the necessary modules at the start. Additional modules are loaded on-demand as users access specific features.
This can be implemented in Angular by using loadChildren in the AppRoutingModule routes configuration, replacing the typical ‘component’ approach.
| const routes: Routes = [ { path: ‘items’, loadChildren: () => import(‘./items/items.module’).then(m => m.ItemsModule) }]; |
Now add a route for the component in the newly lazy loaded module’s routing module
| const routes: Routes = [ { path: ”, component: ItemsComponent } ]; |
4. Web Workers
JavaScript operates on a single-threaded model, meaning it has one main thread executing in the browser. For applications involving intensive tasks like rendering graphs or performing complex calculations, this can lead to performance bottlenecks.
To counteract this, JavaScript introduces “Web Workers” – a code structure that spawns parallel threads alongside the main thread. This allows for simultaneous task execution, ensuring smoother app performance with fewer interruptions.
The implementation of a Web Worker adheres to a specific code format.
| if (typeof Worker !== ‘undefined’) { // Creating a new worker const worker = new Worker(‘./app.worker’, { type: ‘module’ }); worker.onmessage = ({ data }) => { console.log(`message: ${data}`); }; worker.postMessage(‘Web workers at work…’); } else { // fallback mechanism so that your program still executes correctly } |
5. Unsubscribing from Observables
Observables, part of the RxJS library, facilitate data communication between publishers and subscribers in Angular. They support event handling, asynchronous operations, and the management of multiple values. While observables are integral to Angular applications, they’re only active for subscribers.
However, subscriptions to observables can introduce issues, notably memory leaks. These leaks often arise from globally declared variables during subscription. To maintain optimal performance, it’s essential to periodically review and unsubscribe from observables when they’re no longer needed.
A common approach to unsubscribing is:
| let subs: Subscription[] = []; ngOnInit() { this.subs.push(this.service.Subject1.subscribe(() => {})); this.subs.push(this.service.Subject2.subscribe(() => {})); } ngOnDestroy() { subs.forEach(sub => sub.unsubscribe()); } |
6. Preloading Modules
Lazing Loading does good optimization of angular apps by loading modules as per a user’s needs. But this can have an undesirable effect when the router has to fetch other modules from the server which ends up taking more time.
Preloading serves as a solution to this problem. With preloading the router loads all the modules in the background beforehand while the user interacts with only the lazy loaded modules.
Preloading can be incorporated by adding:
| abstract class PreloadingStrategy { abstract preload(route: Route, fn: () => Observable): Observable } |
7. Tree Shaking
Tree-shaking is the methodology used for removing unnecessary dead code from JavaScript. Dead code refers to modules that are left unused during build time. This aids in minimizing build size to the maximum and thereby optimizing the app size.
Tree-Shaking is enabled by default if you use Angular’s CLI.
To enable Tree-Shaking, use the following command:
ng build –prod |
The Dual Nature of Angular
Angular’s strengths can sometimes be seen as its limitations. Its structured framework ensures consistent solutions to common development challenges. However, this rigidity can sometimes curtail a developer’s creativity, preventing them from exploring custom solutions to unique problems.
For optimal results, it’s crucial to approach Angular development holistically. The right development company understands that building and optimizing Angular applications should occur simultaneously to achieve peak efficiency. Partnering with the right Angular development company can make all the difference, ensuring that the application is both robust and flexible to meet diverse needs.
The post 9 Effective Ways to Optimize Performance of Angular Apps in 2023 appeared first on NINTRIVA.
