Angular template loading strategies for efficient web apps

    Wednesday, April 17, 20249 min read268 views
    Angular template loading strategies for efficient web apps

    Making web apps efficient requires a tremendous approach toward making the user interface as simple as possible. In web application development using angular framework, it is very important to load the components in such a way that it does not affect the whole application's process speed. Now to achieve the same, angular has many built-in robust features. These features are used based on the situation of our application. Below we'll discuss some strategies to load our angular templates.

    Different Loading Strategies for Templates

    Lazy Loading Modules & Images

    Generally, an angular app will not lazy load any of its modules unless we provide the functionality for the same. If any of the modules in the app is lazy loaded, then unless we provide the matching route for that module, that particular module will not get loaded in our browser. Once the routes are matched, the module will get loaded and we can access the components inside it accordingly. After loading, if we re-fetch the same route, no action of loading will take place as the module is already loaded.

    • For large enterprises' web applications, lazy loading of modules is the best way by which, the smooth running of application can be achieved. The below example shows the code for achieving lazy modules in angular apps.

      import { NgModule } from '@angular/core';
      import { PreloadAllModules, RouterModule, Routes } from '@angular/router';
      
      const routes: Routes = [
        { 
          path : 'app',
          loadChildren : () => import('./hash-module/hash.module').then(m => 
      								m.HashModule)
        }
      	];
      
      @NgModule({
        imports: [
          RouterModule.forRoot(routes, { preloadingStrategy: PreloadAllModules })
        ],
        exports: [RouterModule]
      })
      export class AppRoutingModule { }

    Above code when executed, will load the HashModule module lazily.

    Using OnPush Change Detection Strategy

    Change detection is a mechanism through which angular detects the changes being made in component data model or in the template. Angular framework detects changes by any one of these two strategies.

    (1) Default: In this strategy, the change detection will get triggered in all components whenever something is getting changed in the application. For example, a click event or a promise execution.

    With the concept called dirty checking, angular compares old values with the new values of the expression and decides whether the view needs to be updated or not. Any component's change detection strategy is set to Default by default.

    (2) OnPush: In this strategy, the change detection will get triggered on some basis only. For example, this strategy triggers when the reference of an input value changes. Input values are the component class's variable decorated with @Input decorator.

    Also, this change detection gets triggered when an event handler is triggered. In order to achieve this strategy, we just have to pass a key-value pair to the configuration of @Component decorator. The key here will be 'changeDetection' & the value for it will be 'ChangeDetectionStrategy.OnPush'. Here, ChangeDetectionStrategy is an ENUM.

    Using NgRx for State Management

    NgRx is nothing but a state management library for Angular which helps to improve the performance of the application. It does so by providing a single source of truth for the application state. Using NgRx for state management in Angular involves leveraging a powerful library to handle the data flow within your application.

    Angular applications often deal with complex data interactions and UI updates, which can become challenging to manage as the application grows. NgRx provides a solution by implementing the Redux pattern, which helps maintain a single source of truth for the application state.

    In simple terms, NgRx helps you keep track of your application's data in a structured way. Imagine your application's state as a big bag containing all the information needed to run your app smoothly. NgRx helps you organize this bag neatly so that you can easily access and update its contents whenever needed.

    When you use NgRx, your application state is stored in a centralized store. Whenever a component needs to access or modify this state, it dispatches actions. These actions are like requests that tell NgRx what needs to be done with the state. NgRx then uses reducers to process these actions and update the state accordingly.

    Another essential feature of NgRx is the use of observables to manage asynchronous operations. This means that your components can subscribe to changes in the state and react accordingly. For example, if a piece of data in the state changes, any component observing that data will be automatically updated to reflect the change.

    Overall, NgRx simplifies the process of managing state in Angular applications by providing a clear structure and predictable flow of data. It promotes separation of concerns, making your codebase more maintainable and easier to debug. By using NgRx, you can build scalable and efficient Angular applications with confidence.

    Using A.O.T Compilation

    A.O.T stands for Ahead Of Time. This compilation is used to improve the application’s performance by compiling the template code during the build process.

    ng build --aot

    A.O.T compilation offers an alternative approach by pre-compiling the typeScript code and processing the templates before deployment. This results in a more streamlined format during the build phase, leading to smaller bundle sizes and faster load times for the application.

    The adoption of A.O.T compilation brings several benefits, including improved performance, quicker load times, and better optimization for production environments.

    Additionally, A.O.T compilation helps to detect template errors during the build process, preventing potential issues in the deployed to illustrate, think of A.O.T compilation as preparing ingredients before cooking a meal.

    Rather than starting from scratch when guests arrive, certain elements are prepared in advance. Consequently, when it's time to serve, everything is quickly assembled, similar to how A.O.T compilation readies Angular applications for rapid loading and efficiency upon user interaction.

    In summary, A.O.T compilation is a critical optimization technique within the Angular framework, enhancing performance and user experience without compromising quality.

    Using Web Workers

    Utilizing Web Workers to load Angular templates involves incorporating separate threads of execution to handle template rendering within an Angular application. Web Workers, which are background scripts running independently from the main execution thread of a web page, come into play here.

    To simplify, when you access a website constructed with Angular, the browser typically processes all required files in a sequential manner. However, this sequential processing can occasionally result in delays in rendering, especially for intricate applications featuring extensive templates.

    By delegating the template rendering process to Web Workers, the main thread can focus on alternative tasks, thereby enhancing overall performance and user responsiveness. This approach proves particularly beneficial for applications with demanding U.I. rendering or processing requirements.

    In essence, integrating Web Workers with Angular allows for the more effective utilization of browser resources, leading to smoother user experiences. It effectively splits the workload across distinct threads, thereby optimizing application performance without hindering the primary user interface.

    Using Immutable Data Structures

    Immutable data structures improve the performance of the application by preventing unnecessary data manipulation. The code snippet below shows the same.

    @Component({
      selector: 'app-root',
      templateUrl: './app.component.html',
    })
    export class AppComponent {
      items = Object.freeze([
        { id: 1, name: 'Item 1' },
        { id: 2, name: 'Item 2' },
        { id: 3, name: 'Item 3' }
      ]);
    }

    Use RxJs for Reactive Programming

    RxJs stands for Reactive Extension for Javascript. The below example shows the execution of Observable in a component.

    import { Component, OnInit } from '@angular/core';
    import { Observable } from 'rxjs';
    
    @Component({
      selector: 'app-example',
      template: `
        <h1>{{ count$ | async }}</h1>
        <button (click)="increment()">Increment</button>
      `
    })
    export class ExampleComponent implements OnInit {
      count$: Observable<number>;
    
      private count = 0;
    
      ngOnInit() {
        this.count$ = new Observable(subscriber => {
          setInterval(() => {
            this.count++;
            subscriber.next(this.count);
          }, 1000);
        });
      }
    
      increment() {
        this.count++;
      }
    }

    Need for Efficient Web Apps

    Till now we have discussed the processes through which we can make our web apps work faster with minimum loading time. But, the question still arises "Is it necessary to make such web applications by implementing the above suggestions ?"

    The answer to this question is of course yes, as making the code efficient for web development has its own advantages. Now, angular components are the most basic U.I building blocks for angular apps. Efficient web apps not only need a responsive design but also require better component build quality, even the full stack projects are developed with Java angular stack or express angular stack.

    The suggestions written above will not only make our applications efficient but also reduce the development time of developers.

    As we know the project scale depends upon the client's requirements, we believe that the above bunch strategies will make the apps work efficiently. One thing that readers should know is that at the end of the day, we just have to deal with HTML, CSS, and database data that we fetch using a server.

    Even if we make our backend very interactive, we should know that the user will always interact with an HTML page. So, it becomes a necessary requirement for the developer or developers to make the user interface interactive and responsive as well and should support most browsers.

    The below image represents common problems developers encounter while developing angular apps.

    image of h2 heading- need for efficient web apps

    Above problems will stop from happening if we apply the strategies.

    Concluductory Thoughts

    Till now we have discussed different strategies for making our angular application efficient. Some concepts like data binding, and interpolation will just help developers to reduce boilerplate code, but if we really want to make the application efficient, then the above strategies can help you to achieve the same.

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