This content originally appeared on Bits and Pieces - Medium and was authored by Jacob Narayan
Creating a custom Angular directive allows developers to extend the HTML syntax and provide custom functionality. In this blog post, we’ll go over the process of creating a custom directive from start to finish.
1. Set Up The Directive
Let’s start by setting up the directive in a new file. Use the @Directive decorator to define our custom directive. This is where we will define the selector for our directive and set any properties or methods that will be used in the template.
import { Directive } from '@angular/core';
@Directive({
selector: '[myCustomDirective]'
})
export class MyCustomDirective {
constructor() { }
}2. Set Up The Template
The next step is to set up the template for our directive. This is where we will define what HTML elements and components should be used when our directive is applied. We can do this by adding an @Input() property to our directive class and using that property in the template.
import { Directive, Input } from '@angular/core';
@Directive({
selector: '[appMyCustomDirective]',
template: `<h1>{{title}}</h1>`
})
export class MyCustomDirective {
@Input() title: string;
constructor() { }
}3. Use The Directive In The Component
Now that we have our directive set up, it’s time to use it in a component. First, make sure to add your custom directive to the declarations array in the ‘app.module.ts’ file. Once you’ve done, that you can start using it in a component by adding the selector for our directive to the component’s template. We can then pass in any data or properties that we want to use in our directive template. For example:
<div appMyCustomDirective [title]="My Title"></div>
4. Style The Directive (Optional)
If we want to style our directive, we can do so by adding a styles property to our @Directive decorator and adding any CSS rules that we want to apply when our directive is used. For example:
import { Directive, Input } from '@angular/core';
@Directive({
selector: '[appMyCustomDirective]',
template: `<h1>{{title}}</h1>`,
styles: [`h1 { color: red; }`]
})
export class MyCustomDirective {
@Input() title: string;
constructor() { }
}This is just a simple attribute directive, but with a little creativity, you can create some really cool reusable components for your Angular application.
💡 Tip: You can use an open-source toolchain such as Bit to “harvest” Angular components from your codebase and share them on bit.dev. You can learn more about this here. This would let your team reuse and collaborate on components to write scalable code, speed up development, and maintain a consistent UI.
Thank you for reading. If you liked this blog, consider following my Medium account for daily blogs about software engineering and technology topics!
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How to Create a Custom Attribute Directive in Angular was originally published in Bits and Pieces on Medium, where people are continuing the conversation by highlighting and responding to this story.
This content originally appeared on Bits and Pieces - Medium and was authored by Jacob Narayan
Jacob Narayan | Sciencx (2023-03-16T15:23:36+00:00) How to Create a Custom Attribute Directive in Angular. Retrieved from https://www.scien.cx/2023/03/16/how-to-create-a-custom-attribute-directive-in-angular/
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