Even Angular itself is written in Typescript. Therefore, prior to beginning Angular, Typescript knowledge is a requirement. And since Angular is written in Typescript, it stands to reason that if we want to write our own bespoke code, we’ll write it in Typescript as well. Here is the Angular Series Roadmap.
What is Angularjs?
An open-source front-end web framework for single-page apps, AngularJS was based on JavaScript. It was mostly kept up by Google and a group of people and businesses. It provided a framework for client-side model-view-controller (MVC) and model-view-ViewModel (MVVM) architectures together with commonly used web application and progressive web application components in an effort to streamline both the building and testing of such applications.
Basic Building blocks of AngularJs
The fundamental AngularJS components that must be used to develop an AngularJS page or application are as follows:
- Module
- Controllers
- Directives
- Data Binding
- Directives
- Services
- Dependency injection
Module:
- A foundational component of an application is an Angular module. It serves as a holding place for a collection of linked elements, including controllers, services, filters, directives, etc. A module can be thought of as a collection of parts and services that your application’s business domain uses to deliver specific functionality.
- For AngularJS, a module is necessary to launch the application. When started, it acts like the app’s home screen. While larger apps may have more than one module, all apps must at least have one root module, all elements of a tiny application can be found in one module, also known as the root module.
Using the AngularJS function, a module is produced. Angular. module
Controllers:
Between a view and a module, an AngularJS controller serves as a middleman. The data in the Angular application is controlled by it. It contains both business logic and data.
- In AngularJS, controllers are regular Javascript objects that are defined using the function Object() { [native code] } function of a Javascript object.
- The $scope object’s initial state and any further actions are added via controllers. An Angular $scope is, as the name implies, an object that contains the scope of a whole model, in this case, a controller.
- In Angular, there are two ways to attach a controller to the DOM: by using the ng-controller command, which creates a new controller object, and a new child scope called “$scope.”
- This child scope is passed as an argument to the function Object() in [native code].
Directives:
In Angular, we employ new syntax, tags, and characteristics that are not included in standard HTML. The word for these is directives. An attribute, an element name, a comment, or a CSS class can all be directives. They only add to the fundamental HTML.
We have a number of built-in Angular directives with the ng-prefix that give our application specified capabilities. Additionally, AngularJS gives you the option to create your own directives.
Some of the built-in instructions include:
- ng-app: The root element of an AngularJS application is this ng-app directive. When launched, this directive sets up an AngularJS application.
- ng-controller: The controller object for an application is defined by the ng-controller directive. This offers a controller instance that may be used to use the data in the view.
- ng-model: The ng-model directive links application data to the value of HTML controls (such as input, text area, select, and checkbox). Additionally, it gives status for the application data and is utilized for type checking for application data.
- ng-init: The ng-init directive specifies an application’s starting values. For instance, this directive can be helpful if you want to provide a default value for your application.
This command may be used by using
- Element Name
- Attribute
- Class
- Comment
Data Binding:
Data binding in AngularJS is a method for automatically synchronizing data between the model and the view. When the data in the model changes, the view is updated as soon as possible, and vice versa when the data in the view changes.
Two distinct types of data, binding exist.
- One-Way Data Binding
- Two-Way Data Binding
One-Way Data Binding
Data binding of this kind is typically found in classical systems. The majority of applications employ a traditional HTML templating system with one-way data binding. They build the view by simultaneously compiling the HTML template and the relevant code. The figure below is visible.
Therefore, any changes to the model are not automatically reflected in the view or vice versa.
Two-Way Data Binding
The developer’s life has been made easier by AngularJS, which also offers great performance and resolutions.
As seen in the figure below, the view is created by first compiling the angularJS template on the browser. If there are any modifications to the view after compilation, the model is also updated. Similar to how changes in the model are quickly mirrored in the view, so too are model changes.
Directives :
Directive on Components It is possible to utilize the element as a directive. Each component includes an Output option, which is used to communicate with the component’s parent HTML elements.
Similar to *ngFor and *ngIf, structural directives allow you to modify the document object model (DOM) by adding or moving nodes using input.
Like the ng-model directive, which provides two-way data binding, an attribute directive helps to add behavior to or change the appearance of a particular element.
Services:
Services just facilitate service reuse. Naturally, as the project grows, other components will be added, and those components will need access to data as well. As a result, whenever you copy and paste code, only one singleton data service is produced.
Dependency Injection :
Use dependency injection to give the framework and your application flexibility, extensibility, and testability by injecting the required dependencies for a given component or service at runtime.
In order to create an instance of Service and send it to our AppComponent, we must explicitly tell Angular to do so. It is known as Dependency Injection. Therefore, we should tell Angular to include this component’s dependency in its function Object() { [native code] }.
