AnassAzeroual/performance-hunter

Performance-hunter

Angular Application Performance Optimization Guide This guide outlines effective strategies to optimize your Angular application for speed, efficiency, and scalability.

Change Detection

• OnPush Change Detection Strategy: Reduce unnecessary re-renders by employing the OnPush strategy for components with frequent data updates. This strategy only triggers change detection when an input property changes.

  import { ChangeDetectionStrategy } from "@angular/core";

  @Component({
    selector: "app-my-component",
    templateUrl: "./my-component.component.html",
    styleUrls: ["./my-component.component.css"],
    changeDetection: ChangeDetectionStrategy.OnPush,
  })
  export class MyComponent {
    // ...
  }

Utilisez ce code avec précaution.

Component Optimization

• Lazy Loading: Break down your application into feature modules and load them on demand using lazy loading.

  const routes: Routes = [
  { path: '', component: HomeComponent },
  {
  path: 'features',
  loadChildren: () => import('./features/features.module').then(m => m.FeaturesModule)
  }
  ];

    @NgModule({
    imports: [RouterModule.forRoot(routes)],
    // ...
    })

export class AppModule { } Utilisez ce code avec précaution.

• TrackBy in ngFor Loops: Optimize ngFor loops with large datasets by implementing the trackBy function to improve performance.

items = [
{ id: 1, name: 'Item 1' },
{ id: 2, name: 'Item 2' },
// ...
];

trackByItemId(index: number, item: any) {
return item.id;
}

Utilisez ce code avec précaution.

• Avoid Complex ngIf Expressions: If conditional logic within ngIf directives involves complex expressions, consider employing alternative approaches like ngSwitch or creating separate components for different conditions. Data Management

• Immutable Data Structures Whenever possible:, utilize immutable data structures (e.g., const for objects, spread operator (...) for updates). This approach forces a new object reference to be created, prompting Angular to perform change detection efficiently.

// Mutable (avoid)
items = [1, 2, 3];
items.push(4); // Mutates the original array

// Immutable (preferred)
const updatedItems = [...items, 4];
items = updatedItems;

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• Memoization For functions that produce the same output for identical inputs:, leverage memoization techniques to cache results. This prevents redundant calculations and improves performance.

function fibonacci(n: number): number {
if (n <= 1) {
return n;
}

let memo: { [key: number]: number } = {};
const fib = (n: number): number => {
if (memo[n]) {
return memo[n];
}
memo[n] = fib(n - 1) + fib(n - 2);
return memo[n];
};

return fib(n);
}

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• RxJS Pipes for Data Transformations When dealing with frequent data updates:, RxJS pipes offer a declarative way to transform and handle data streams. Pipes are optimized for efficiency, and you can chain them together for complex transformations.

import { map, filter } from 'rxjs/operators';

data$ = someData$.pipe(
map(item => item \* 2), // Double each item
filter(item => item > 5) // Filter items greater than 5
);

Utilisez ce code avec précaution. Build and Deployment

• Ahead-of-Time (AOT) Compilation: Pre-compile your Angular application to JavaScript code during the build process using AOT compilation. This improves runtime performance by eliminating the need for on-the-fly compilation in the browser. shell ng build --configuration=production Utilisez ce code avec précaution.

• Tree-Shaking: Enable tree-shaking when building your application to remove unused code from the final bundle. This reduces the overall application size and enhances loading times. Tree-shaking is typically enabled by default in production builds.

• Code Splitting: Split your application code into smaller chunks using techniques like dynamic imports or lazy loading. This allows browsers to load only the necessary code initially, improving perceived performance.