Developers support using AngularJS due to its open-source libraries and rich developer community. Besides, it allows easy code-reusability, allows parallel development, offers interesting plug-and-play components, and offers improved design architecture for overall quicker AngularJS development.
Well, there are numerous reasons to pick AngularJS for app development. One of the reasons could be to migrate the ng1 app to ng2+, where componentization of the app becomes necessary for seamless migration.
This article will help you learn how developers use the AngularJS features to create some reusable components for the app that perfectly align with the Angular framework.
The first step for AngularJs programmers is to understand every component’s role for its apt application further. Then, we will utilize all reusable or dumb components to handle the common tasks while keeping page-level components as the driving force behind a view. Simply put, it will encapsulate functionality and code into reusable bits besides keeping the page-specific logic into a single component.
The easiest component appears something like this.
angular.module('app', [])
.component('myComponent', {
template:'<h1>Hello World</h1>'
}
);
Since the directives are available to the developers, it would only be rare cases when they still wish to utilize the template directive and not the component. Directives must be used as attributes to add functionality to the component. Well, when you feel stuck or doubtful about it, you may simply prefer the component model, which structures like a tree of components. Simply put, directives act more or less like a template-less component responsible for enhancing the components.
The parameters of Components are passed through the bindings property.
angular.module('myApp')
.component('myComponent', {
template:'<h1>$ctrl.name</h1>',
bindings:{
name: '<' //one way data binding
},
controller: function(){
//component controller
}
})
* < - One-way data binding
You need to utilize one-way data binding for your bindings. Two-way data bindings are one of the cleanest AngularJS features. However, the bound properties are watched with component scope. Also, it comes with a high-performance cost. Simply put, if you are using two-way binding, any change that you make in the component scope will reflect in the parent.
* = - Two-way data binding
If you still need this, here is what you need.
* & - Output event. Provides a hook to parent components
If the bindings are marked with ‘&,’ it indicates a callback function from the parent component. So, the parent easily catches any changes or messages, allowing the dumb components to talk to the parent component.
* @ - String input
For instance, we are developing a messenger app for the business. Hence, we will have the main view, i.e., a page-level component incorporating a reusable contact list component. Since we will be further using the contact list component in different areas of the app, it is imperative to make it as reusable as possible. With the ultimate objective of rending the contact list available to us from the server, it is to be done. Hence, the messenger component must accept the selections done in the contact list component and implement them aptly in the recipient list.
The contact list we use is a facilitator to the page-level component, which is usually the dumb component. It is known as a dumb component because it barely knows anything about the messages we send or even about the recipients. So, the call is done by a dumb component to the parent to pass the key-value pair for parameters. This ensures that the parent component remains unaffected due to the ordering of parameters as you listen for changes.
Developing AngularJS using the method above is quite contributing to enhancing the performance of the app. Besides, it even helps the developer set up highly reusable components for your app. So we hope this guide has helped you build reusable components in AngularJS quickly, without any hassle.