Hi readers 馃憢, thank you for spending few minutes of the day, reading my article.
I have recently started learning Angular and as the heading says, this is a beginner level series. As I proceed with my learning, I shall come up with some more articles and projects (if you see me away for more than 2 weeks, I probably need your help and motivation 馃檹馃徑).
In this article we will be covering basics of Components.
What is a Component?
Component are the most essential and important building blocks of Angular. It consists of:
- An HTML file that declares what goes on the page (also called the template of the component)
- A typescript class that defines behavior (also known as the component class)
- A CSS selector that defines how the component is used
Creating a Component
- Have Angular CLI installed. If not, use command
npm install -g @angular/cli
to install. - Create an Angular workspace using the command
ng new <app-name>
- Run
ng generate component <component-name>
to create a component - If it runs successfully, you should see:
- A folder named after the component
- A component file
- A template file
- A CSS file
- A testing specification file
This is what your workspace should look like, after running the above command 馃憞
Alternatively, you can also create a component manually, follow this tutorial to know more.
Getting into details
- Open the file
app.component.ts
under your newly created component folder It should be similar to 馃憞
-
@Component is a decorator that identifies the class immediately below it as a component class, and specifies its metadata. The metadata for a component tells Angular where to get the major building blocks that it needs. The @Component decorator, can be used to set the values of different properties, some of which are:
- Template and TemplateURL
- Provider
- Selector
-
Template and TemplateURL- A template is the part of the component which gets rendered on the page. A template can be created in two ways:
- Inline template: Can be created using single or double quotes
- TemplateUrl property: Helps us in setting complex templates that are created in an HTML file
Provider - Providers are passed as an array, and it helps in adding services in a component.
Selector - It tells Angular to create and insert an instance of this component wherever it finds the corresponding tag in template HTML. In simple terms, a component can be used using this selector.
Thank you for reading till the end. In the next article, we will be cover Data Binding basics.
If you have any comments for me, please drop them below or reach out to me at @HaimantikaM