Course Content

Introduction to Angular

1. Angular Fundamentals

What is Angular?The Evolution and Stability of Angular Key Principles of the Framework Setting Up the Environment Getting Started with Angular CLI Angular Project Structure

2. Components and Templates

What Is a Component?The Main Component in Angular Creating a Component Types of Data Binding in Angular Component and Template Interaction in Angular Communication Between Components in Angular

3. Mastering Angular Directives and Pipes

Introduction to Directives in Angular Structural Directives in Angular Attribute Directives in Angular Creating Custom Directives in Angular Introduction to Pipes Creating a Custom Pipe in Angular

4. Services and Dependency Injection in Angular

Introduction to Angular Services Creating a Custom Service in Angular Service Injection into a Component Adding Functionality to Our Application Saving Data to Local Storage in Angular

5. Standalone Components & Modules

Introduction to Modules in Angular Modular Architecture in Angular Transition to Standalone Components How Standalone Components Work in Angular

6. Routing and Navigation in Angular

Routing Basics in Angular Implementing the TaskDetailsComponent Setting Up Routing in Angular Component Communication and Navigation Handling Non-Existent Routes in Angular

Types of Data Binding in Angular

When a component and its template interact, we can pass data and events between them in different ways. This is called data binding.

In Angular, there are four types of data binding, each serving a specific purpose.

Let's take a look at how they work using a simple task component as an example:

task-component


              123456789101112131415
            
import { Component } from '@angular/core';

@Component({
  selector: 'task-component',
  standalone: true,
  templateUrl: './task-component.component.html',
  styleUrls: ['./task-component.component.css']
})
export class TaskComponent {
  task = {
    id: 1,
    title: 'Buy groceries',
    completed: false
  };
}

Here, we create a task object with three properties: id, title, and completed. These properties describe a specific task—its name and whether it has been completed.

Interpolation

For example, if you have a variable like task.title, you can wrap it in {{ }}, and Angular will render its value into the HTML.


python

When Angular processes the template, it finds the expression {{ task.title }} and replaces it with the current value of task.title from the component.

If the value is 'Buy groceries', that's exactly what will appear inside the <h3> tag. The same process applies to any other values you interpolate.

So, interpolation is one-way: data flows from the component to the template, and the user simply sees the result.

Property Binding

Sometimes, you don't just want to show text — you want to control element behavior, like disabling a button, setting an image source, or checking a checkbox.

Angular lets you bind values to HTML element properties using square brackets.


python

Imagine the task is already completed (task.completed = true). In that case, we want the button to be disabled. When Angular sees [disabled]="task.completed", it takes the value from the component and binds it to the DOM element's disabled property.

If the value is true, the button becomes disabled. If it's false, the button stays active.

Again, this is one-way binding: the data flows from the component to the template, and the template adjusts based on the current state of the task object.

Event Binding

To make your app respond to user actions (like clicks), Angular provides event binding. When a user interacts with an element, you can "catch" that event and call a method in your component.

Let's add a method to the component:


python

And update the template:


python

When the user clicks the button, Angular detects the (click) event and calls the toggleComplete() method in the component. This method toggles the value of task.completed. After that, Angular re-renders the template, and thanks to interpolation ({{ task.completed ? 'Undo' : 'Complete' }}), the button text updates instantly.

Here, data flows one way — from the template back into the component (you pass an action inward).

Two-Way Binding

Sometimes you want changes in the template (like typing into an input field) to immediately update the component — and changes in the component to immediately update the template. Angular makes this easy with two-way binding using [(ngModel)].

Important: To use [(ngModel)], you must import the FormsModule — as shown below:

task-component


              1234567891011121314151617181920
            
import { FormsModule } from '@angular/forms';

@Component({
  selector: 'task-component',
  standalone: true,
  imports: [FormsModule], // ❗ don't forget to import `FormsModule` for standalone components
  templateUrl: './task-component.component.html',
  styleUrls: ['./task-component.component.css']
})
export class TaskComponent {
  task = {
    id: 1,
    title: 'Buy groceries',
    completed: false
  };

  toggleComplete() {
    this.task.completed = !this.task.completed;
  }
}

And here's the template:


python

This is where the magic of two-way binding happens. When a user types into the input field, Angular automatically updates task.title inside the component. And when task.title changes in the component, Angular immediately reflects that update in the input field.

Unlike the other types of binding, two-way binding keeps the component and the template in sync at all times.

Key Differences

Each of these binding methods has its own features and is best suited for different scenarios of data interaction within an application.

Everything was clear?

Thanks for your feedback!

Section 2. Chapter 4

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Course Content

Introduction to Angular

1. Angular Fundamentals

What is Angular?The Evolution and Stability of Angular Key Principles of the Framework Setting Up the Environment Getting Started with Angular CLI Angular Project Structure

2. Components and Templates

What Is a Component?The Main Component in Angular Creating a Component Types of Data Binding in Angular Component and Template Interaction in Angular Communication Between Components in Angular

3. Mastering Angular Directives and Pipes

Introduction to Directives in Angular Structural Directives in Angular Attribute Directives in Angular Creating Custom Directives in Angular Introduction to Pipes Creating a Custom Pipe in Angular

4. Services and Dependency Injection in Angular

Introduction to Angular Services Creating a Custom Service in Angular Service Injection into a Component Adding Functionality to Our Application Saving Data to Local Storage in Angular

5. Standalone Components & Modules

Introduction to Modules in Angular Modular Architecture in Angular Transition to Standalone Components How Standalone Components Work in Angular

6. Routing and Navigation in Angular

Routing Basics in Angular Implementing the TaskDetailsComponent Setting Up Routing in Angular Component Communication and Navigation Handling Non-Existent Routes in Angular

Types of Data Binding in Angular

When a component and its template interact, we can pass data and events between them in different ways. This is called data binding.

In Angular, there are four types of data binding, each serving a specific purpose.

Let's take a look at how they work using a simple task component as an example:

task-component


              123456789101112131415
            
import { Component } from '@angular/core';

@Component({
  selector: 'task-component',
  standalone: true,
  templateUrl: './task-component.component.html',
  styleUrls: ['./task-component.component.css']
})
export class TaskComponent {
  task = {
    id: 1,
    title: 'Buy groceries',
    completed: false
  };
}

Here, we create a task object with three properties: id, title, and completed. These properties describe a specific task—its name and whether it has been completed.

Interpolation

For example, if you have a variable like task.title, you can wrap it in {{ }}, and Angular will render its value into the HTML.


python

When Angular processes the template, it finds the expression {{ task.title }} and replaces it with the current value of task.title from the component.

If the value is 'Buy groceries', that's exactly what will appear inside the <h3> tag. The same process applies to any other values you interpolate.

So, interpolation is one-way: data flows from the component to the template, and the user simply sees the result.

Property Binding

Sometimes, you don't just want to show text — you want to control element behavior, like disabling a button, setting an image source, or checking a checkbox.

Angular lets you bind values to HTML element properties using square brackets.


python

If the value is true, the button becomes disabled. If it's false, the button stays active.

Again, this is one-way binding: the data flows from the component to the template, and the template adjusts based on the current state of the task object.

Event Binding

To make your app respond to user actions (like clicks), Angular provides event binding. When a user interacts with an element, you can "catch" that event and call a method in your component.

Let's add a method to the component:


python

And update the template:


python

Here, data flows one way — from the template back into the component (you pass an action inward).

Two-Way Binding

Important: To use [(ngModel)], you must import the FormsModule — as shown below:

task-component


              1234567891011121314151617181920
            
import { FormsModule } from '@angular/forms';

@Component({
  selector: 'task-component',
  standalone: true,
  imports: [FormsModule], // ❗ don't forget to import `FormsModule` for standalone components
  templateUrl: './task-component.component.html',
  styleUrls: ['./task-component.component.css']
})
export class TaskComponent {
  task = {
    id: 1,
    title: 'Buy groceries',
    completed: false
  };

  toggleComplete() {
    this.task.completed = !this.task.completed;
  }
}

And here's the template:


python

Unlike the other types of binding, two-way binding keeps the component and the template in sync at all times.

Key Differences

Each of these binding methods has its own features and is best suited for different scenarios of data interaction within an application.

Everything was clear?

Thanks for your feedback!

Section 2. Chapter 4

Introduction to Angular

Types of Data Binding in Angular

Interpolation

Property Binding

Event Binding

Two-Way Binding

Key Differences

1. Which type of data binding is used to display the value of a component's variable in the template?

2. Which type of data binding allows you to update a component's variable through a form and keeps it synchronized with the input element in the template?

3. Which type of data binding would you use to make a button disabled when a task is completed?

4. Which type of data binding allows you to trigger a component method when a button is clicked?

Introduction to Angular

Types of Data Binding in Angular

Interpolation

Property Binding

Event Binding

Two-Way Binding

Key Differences

1. Which type of data binding is used to display the value of a component's variable in the template?

2. Which type of data binding allows you to update a component's variable through a form and keeps it synchronized with the input element in the template?

3. Which type of data binding would you use to make a button disabled when a task is completed?

4. Which type of data binding allows you to trigger a component method when a button is clicked?