To build client applications in HTML and TypeScript, the Angular 8 is used as a platform and a framework. Being written in TypeScript, the Angular 8 is designed to implement core and optional functionality as a set of TypeScript libraries. These libraries can be imported into an app. The NgModules are the basic building blocks of an Angular application. It facilitates a compilation context for components. The related code is collected by the NgModules into functional sets. A set of the NgModules defines an Angular app. At least one root module is present in an Angular app to enable bootstrapping. There can be many more feature modules.
- The sets of screen elements that are chosen and modified as per the logic of a program and data by Angular 8 are called views in Angular 8 and are defined by the components.
- Services in Angular 8 serve specific purposes not directly related to views and are used by the components. To make a code modular, reusable, and effective the Service providers can be introduced into the components as dependencies.
Key parts of Angular 8 Architecture:
- Dependency Injection
Angular 8 Components:
Just like services, Components are simple classes with decorators. They mark their types and present metadata to guide Angular to serve. The root component is always included in every Angular application as a component. A page hierarchy is connected with page DOM by using the root component. A class is defined by each component to include application data and logic. Each component is associated with an HTML template. It specifies a view to be displayed in a target environment.
Metadata of Angular 8 Component class:
- A component class is associated with a template that defines a view by the metadata for that component class. The ordinary HTML is combined with Angular directives and binding markup by a template. Thus, the Angular is allowed to modify the HTML before executing it for display.
- The information that the Angular needs to provide to the components through dependency injection (DI) is facilitated by the metadata for a service class.
Angular 8 Modules:
- Own functionalities are allowed by the NgModules that can be exported and used by other NgModules. For instance, import the Router NgModule to use the router service in an app.
Angular 8 Template, Directives and Data Binding:
To combine HTML with Angular Markup, the template is used in Angular 8. It also modifies the HTML elements before displaying them. The program logic is provided by the Template directives, and to connect the data of an application and the DOM, the binding markup is utilized. Data binding can be classified into two types:
- Angular 8 Event Binding: It binds events to an app. It is also used to respond to user input in the target environment by updating the data of the application.
- Angular 8 Property Binding: It passes data from the component class. It also facilitates the user to interpolate values that are estimated from the data of the application into the HTML.
Angular 8 Services and Dependency Injection:
For data or logic that isn’t associated with a specific view, and is required to share across components, a service class is created by the developers in Angular 8. To make lean and effective component classes, the Dependency Injection (DI) is used. DI simply renders the tasks like fetching data from the server, validating user input, or logging directly to the console; to services.
Angular 8 Routing:
The router is a NgModule in Angular 8. It renders a service to facilitate the developers to determine a navigation path among the varied application states and to see hierarchies in their app. The router and the navigation of a browser work in the same way.
- The browser navigates to the corresponding page on entering a URL in the address bar.
- The browser navigates to a new page on clicking the link on a page.
- The browser navigates backwards or forwards according to the user’s seen history pages on clicking the browser’s back or forward buttons.