Ever wonder how the magic happens in Angular? Yes, we’re diving deep into the heart of Angular components today. Imagine them as the backbone, the very soul of your Angular applications.
But why should you care, you ask? Because mastering components is like unlocking a new level in a game – it’s where the real fun begins.
Now, why should you, as a startup, care about Angular components? Imagine crafting a user experience that’s not just seamless but also stunningly efficient. That’s the potential power Angular components hand you on a silver platter.
They’re all about enhancing your application’s interactivity, breaking down complex UIs into manageable, reusable pieces. Whether you’re aiming to captivate your audience with intuitive interfaces or looking to speed up your development cycle, understanding
Angular components is your first step towards achieving that goal.
Let’s get started!
What are the components in Angular?
A Component in Angular serves as a fundamental building block for an Angular application. It consists of a template and a class that governs a specific section of the screen. The class defines the behavior of the component through its attributes and methods, while the template determines its structure and appearance on the screen.
The purpose of components is to break down a large application into smaller, more manageable, and self-contained units. By utilizing inputs, outputs, and services, components can communicate with each other, resulting in a modular and easily maintainable application.
Angular components are designed to be reusable and can be nested within other components, enabling developers to create intricate user interfaces by combining smaller, simpler components. Through inputs, outputs, and services, components can establish connections with one another, simplifying the handling of complex interactions between different parts of the program.
Here is an illustration of a basic Angular component:
In this instance, we introduce an Angular component named GreetingComponent. The component is established using the ‘@Component’ decorator, which imparts metadata about the component to Angular. The selector property specifies the HTML tag that will be utilized to display the component in the template, in this scenario ‘<app-greeting>’.
The template property defines the HTML template for the component, which includes a single H1 header. The header exhibits the value of the message property, which is linked to the template using Angular template syntax {{}}.
The styles property specifies the CSS styles for the component, which are confined and relevant to the component. In this instance, the H1 header has a green color.
The class GreetingComponent determines the functionality of the component. It contains a single message property, which is a string.
Upon utilizing this component in the application, the template will be displayed as HTML, and the functionality of the component will be determined by the class. The H1 header will exhibit the message “Hello, World!”, and the text will be shown in green.
Key Parts of an Angular Component
An Angular component comprises multiple elements, including:
1.Component Decorator:
This JavaScript function is utilized to specify the metadata of a component, encompassing details like its selector, template, styles, and properties.
2.Selector:
A string that identifies the component’s name in templates.
3.Template:
Either a string or a reference to an external file that outlines the HTML structure of the component.
4.Styles:
A string or a reference to an external file that dictates the CSS styles for the component.
5.Class:
A JavaScript class that outlines the properties and methods of the component.
6.Input properties:
Properties passed from a parent component to a child component are known as input properties. These properties are defined using the ‘@Input’ decorator and facilitate data binding between the parent and child components.
7.Output properties:
On the other hand, are properties emitted from a child component to a parent component. They are defined using the ‘@Output’ decorator and are useful for informing the parent component about any changes in the child component.
8.Lifecycle hooks:
Lifecycle hooks are special methods that are triggered at key points in the creation, update, and destruction of a component. They offer developers the ability to execute custom logic at specific stages of a component’s lifecycle.
Angular Component Lifecycle Hooks
Angular provides a set of 8 lifecycle hooks that allow developers to perform specific actions at different stages of a component’s lifecycle. These events play a crucial role in managing the behavior and functionality of Angular components.
1. ngOnChanges:
The ngOnChanges event is triggered whenever there is a change in the input binding value of a component. It receives an object that contains the old and new values of each changed input property. This event is called before ngOnInit and can be utilized to respond to changes in input data.
2. ngOnInit:
The ngOnInit event occurs after the constructor of the component and the initial call to ngOnChanges. It is an ideal place to perform component initialization tasks, such as fetching data or initializing local variables.
3. ngDoCheck:
The ngDoCheck event is triggered whenever Angular performs change detection on the component. Change detection is the process by which Angular checks for changes in component data and updates the component’s view accordingly. The ngDoCheck method can be used to implement custom change detection logic, such as deep checking of complex objects.
4. ngDoCheck:
The ngAfterContentInit event takes place when Angular has processed the content projected into the component using ng-content. It is a suitable place to perform initialization logic for the projected content.
5. ngAfterContentChecked:
After each check of the component’s content, the ngAfterContentChecked event is called. This event can be used to perform logic that depends on the component’s content, such as updating the count of items in the content.
6. ngAfterViewInit:
The ngAfterViewInit event occurs when Angular has evaluated the views of the component and its child views. It is a good place to perform logic that depends on the component’s view and child views, such as accessing elements in the view.
These lifecycle events provide developers with the flexibility to execute specific actions at different stages of a component’s lifecycle, enabling them to effectively manage and control the behavior and functionality of Angular components.
7. ngAfterViewInitChecked:
This event is called after each check of the component’s views (and child views). This event can be used to perform logic that depends on the component’s views, such as responding to changes in view data.
8. ngOnDestroy:
This occurrence takes place immediately before the component is destroyed. This event is a good place to perform cleanup logic, such as unsubscribing from observables, removing event listeners, and clearing timers.
Angular styles in component
In Angular, components can have styles applied in various ways. Each component can have its own styles defined through methods such as:
1. Inline styles: Styles can be directly defined in the component’s template using the style attribute. This is a straightforward approach to styling components, but may not be as manageable for larger projects.
2. Component-level styles: Styles can be defined for a component in its own ‘.css’ file. These styles will only affect the component and its child components.
3. Global styles: Styles can be defined in a global ‘.css’ file that will be applied across the entire application.
4. Sass/SCSS styles: Angular supports Sass/SCSS styles, offering features like variables, functions, and mixins.
The scope of styles applied to a component can be controlled using the encapsulation property of the component. By default, Angular uses “emulated” encapsulation, meaning that the component’s styles are contained to the component and its child components, but are not isolated from the rest of the application.
To change the encapsulation, you can set the encapsulation property in the component’s metadata to either ‘ViewEncapsulation.None’ or ‘ViewEncapsulation.ShadowDom’. If you set it to ‘ViewEncapsulation.None’, the component’s styles will be global and affect the entire application. If you set it to ‘ViewEncapsulation.ShadowDom’, the component’s styles will be scoped to the component and its child components, and will not affect the rest of the application.
Angular directives VS components
| Angular Components | Angular Directives |
| In Angular, the Component is the one that provides data to the view. It is used to create a new View(Shadow DOM) with attached behavior. | Directives in Angular are primarily used to add additional behavior to an existing DOM element or an existing component instance. |
| The Component is always an element (‘E’). | The directive can be an attribute, element name, comment, or CSS class (‘E’, ‘A’, ‘C’, ‘M’). |
| Templates are the must-have aspects when it comes to components. | Templates are not mandatory elements when working with directives. |
| Despite the fact that the component makes it easier for developers to write simpler and more effective code, it does not support key functions like ‘compile’ and ‘pre-link’. | Directives, on the other hand, feature more functions. They can be used for manipulating DOM objects effortlessly. |
| To work with components, developers have to use @Component meta-data annotation. | To work with directives, developers have to use @Directive meta-data annotation. |
| Given that components are used to break down an application into smaller parts, they are widely used by developers. They can build applications via a complete component-based model. | Developers use directives mainly to build reusable components, which results in a more behavior-oriented model. |
| Components cannot be used to make changes to any data or the DOM that is out of the scope. | Directives feature isolated scopes. This means that by default the child inherits the scope from its parent. |
| There can only be one component per DOM element. | There can be more than one directive in a DOM element. |
| As the Component has views, viewEncapsulation can be defined. | The Directive does not have views. Hence, developers cannot use viewEncapsulation in the directive. |
How to implement an angular component?
To implement an Angular js components for the success of angular development services, you need to follow these steps:
1. Create the component class:
Develop a new TypeScript class and utilize the ‘@Component’ decorator to specify the metadata for the component. This metadata should include the selector, template, and styles for the component.
2. Define the template:
The template can be created inline as a string or in an external file, which is then referenced in the component metadata. Within the template, you can utilize Angular templates, directives, and data bindings to structure the component.
3. Define the class:
Within the class, you can define the properties and methods of the component. Use the ‘@Input’ and ‘@Output’ decorators to specify input and output properties. Additionally, you can implement lifecycle hooks to execute logic at specific stages of the component’s lifecycle.
4. Register the component:
To use the component in your application, you must register it in an Angular module. This can be done by adding it to the declarations array of the module.
Why Nintriva is Your Reliable Partner for Your Angular Development Services?
Nintriva is dedicated to serving you through the latest technological advancements, ensuring that your project is future-ready. Nintriva’s team’s understanding of Angular is unparalleled, and their approach to development is centered around your unique needs.
Fast Paced Development:
Nintriva’s design, build and deploy next-gen angular applications that are aligned to your business requirements.
Quality Bound Solutions:
High-quality angular solutions that are developed from effective and clean coding processes.
High Performing Applications:
Efficient, scalable, and high-performing applications with robust architecture.
Time-Bound Development:
Iterative and flexible development approach that is committed to deadlines.
Connect for Your Angular Projects ?
Nintriva is committed to delivering end-to-end Angular solutions. From ideation to deployment, their approach is structured to ensure that your business goals directly influence the technical choices made.
They specialize in creating scalable and secure Angular applications that provide a seamless experience across all devices.
Their expertise spans various industry verticals, with a focus on BFSI, E-commerce, and Education sectors. They cater to a diverse clientele, from startups to global enterprises, and have earned a reputation for excellence in delivering an innovative and high-quality solution. Let’s check the major projects they are working on Angular.
- BIZ Boon: BizBoon connects Indian organizations and individuals entering or established in the US and Canada with local firms and institutions.
- Column Technologies: Addressing Human Resource requests and inquiries are critical to the overall morale and productivity of an organization, and understand they must be addressed in a timely manner.
- eDoctorBook: Its an online platform enabling seamless and effortless interaction between patients and doctors.
Wrapping up
Understanding Angular components is a pivotal step in your Angular learning journey. They are the backbone of Angular applications, and a solid grasp of their structure and functionality is vital. We’ve covered the basic anatomy of an Angular component, its lifecycle, and provided detailed insights to help beginners get started.
Remember, with Angular’s modularity and reusability, components can be used to create complex applications that are easy to build, test, and maintain. As you become more familiar with these concepts, you’ll be able to build powerful, responsive, and dynamic web applications that cater to the modern user’s requirements.
Now, armed with this knowledge, tackle your first Angular components with confidence and continue on your path to becoming an accomplished Angular developer. If you have further questions or need assistance with your Angular endeavors, remember that Nintriva is here to be your trusted partner. Contact us to get instant help from our side.
FAQ’s
What is an Angular component?
An Angular component is a building block of an Angular application, representing a reusable and self-contained piece of user interface with its own logic and view.
How do I create a component in Angular?
To create a component in Angular, you can use the Angular CLI (ng generate component) or manually create the necessary files, including a TypeScript class, an HTML template, and a CSS style file.
How can components communicate with each other in Angular?
Components can communicate in Angular through input and output properties, ViewChild/ViewChildren, and services for more complex scenarios.
What are Angular directives, and how are they related to components?
Directives in Angular are markers on a DOM element that tells Angular to do something with that element. Components are a type of directive with a template.