Category: Working with null values

REST API consumption – Angular Services and the Singleton Pattern-1

One of the main uses of Angular services is undoubtedly communication with the backend of the application, using the Representational State Transfer (REST) protocol.Let’s learn about this feature in practice by preparing our project to…

Communication between components using services – Angular Services and the Singleton Pattern

A characteristic that we must understand about Angular services is that, by default, every service instantiated by the dependency injection mechanism has the same reference; that is, a new object is not created, but reused.This…

Creating services – Angular Services and the Singleton Pattern

Services in Angular are TypeScript classes that aim to implement business logic for our interfaces. Business logic in a frontend project can seem like a controversial issue because ideally, all logic and processing should take…

Propagating events from nested components – Components and Pages

We will add the options to delete an item from the list and increase the number of repetitions to our diary. First, let’s add the buttons to the list item template. In the entry-item.component.html file,…

Creating components – Components and Pages-1

The main building blocks of an Angular application are the components. It is by using them that we assemble our user interfaces and define the flow of the experience. In Angular architecture, components organize an…

Using a better alternative to the any type – TypeScript Patterns for Angular

In the development of TypeScript applications, we may have situations where we do not know which type of parameter we are going to receive, such as the return of an API. What is trafficked can…

Validating types – type guards – TypeScript Patterns for Angular

Now that we know the TypeScript inference mechanism, we can understand another feature present in it, type guards. Let’s consider these in the following example:function getDiscount(value: string | number) { if (typeof value === “number”) { return…

Working with null values – TypeScript Patterns for Angular

In TypeScript, by default, all function and method parameters are required and checked by the transpiler.If any parameter is optional, we can define it in the type it represents, as in the following example: function…

Creating methods and functions – TypeScript Patterns for Angular

One of the best ways used by TypeScript to improve the developer experience in Angular application development is through the ability to type parameters and return functions and methods. Both for developers who create libraries…

Creating classes and types – TypeScript Patterns for Angular

Since version 2 of the framework, Angular is based on TypeScript for its development, both internally and for those who use it to build applications. This was a controversial decision at the time, as this…