One of the most popular Angular interview questions is, whether a service is singleton? By default, when you create a service using the below CLI command, ng g s app AppService is singleton, however it can be re-provided to create more objects of it. Say, you again re provide AppService in one of the components, … Continue reading Angular Interview : is Angular Service Singleton ?
Angular
Change Detection in Angular
Change Detection is the backbone of the Angular framework, and each component has its own change detector. This article explains change detection strategies and optimizations to help you write highly performant Angular applications. Angular can detect when data changes in the component, and can re-render the view to display the updated data. Angular makes sure … Continue reading Change Detection in Angular
How to use conditions in Angular Template using
There are various ways you can apply conditions on Angular Template. Usually, you apply conditions to show a particular value or render a specific element based on a condition. In this post, let us see, the simplest way of achieving the conditions in Angular Template using the <ng-container> and <ng-template>. To start with consider data, … Continue reading How to use conditions in Angular Template using
Why use exportAs Property in Angular
Have you used exportAs property of a directive? It could be instrumental in working with public methods of a directive. Let us say; you have created a custom directive to change the background colour of the host element on the mouse hover as below, import { Directive, Input, HostListener, ElementRef } from '@angular/core'; @Directive({ selector: … Continue reading Why use exportAs Property in Angular
When to use viewProviders in Angular – Simplified
I have often seen developers are confused about viewProviders property of the @Componnet decorator. This post explains to you about the viewProviders option. The viewProviders defines the set of injectable objects that are visible to its view, DOM children. They are not visible to the content children. At the component level, you can provide a service in two ways: Using the providers arrayUsing the viewProviders array. If … Continue reading When to use viewProviders in Angular – Simplified
How to use useClass with Tree Shakable Services in Angular
Recently, I was asked that how can we use providers such as useClass inside a Tree Shakable service? By default, Angular services are tree shakable, which means if the application does not use them, they are not part of the final bundle. So, if you create a service using CLI as, ng g s Log … Continue reading How to use useClass with Tree Shakable Services in Angular
Do Angular useExisting providers create a new object of service?
Short answer is NO, the useExisting provider use object created by other tokens. Read on, To learn more about such concepts, join a free webinar on Saturday, 20 June 4 PM IST. RSVP here: https://www.meetup.com/Geek97/events/271292371/ In Angular, providers determine how an object of a particular token gets created. That means whether Angular creates a new … Continue reading Do Angular useExisting providers create a new object of service?
How to use different syntax for Angular Interpolation
How to use different syntax for Angular Interpolation
How to use Interceptor in Angular
Interceptors are used to intercepts HTTP requests and responses from the application. You can handle them or transform them before passing it on. For example, you can use an interceptor to add authorization token before passing the HTTP request or cache the HTTP response. Some of the usages of interceptors are as follows, Caching of … Continue reading How to use Interceptor in Angular
When to use the subscribe method or async pipe in Angular?
This post explains when to use subscribe method or async pipe in working with observable data in an Angular application
