@herodevs/dynamic-component-service

DynamicComponentService

A service that makes dynamically creating components easy.

When you use DynamicComponentService to create a component, you are given backed an ICreatedComponentInterface which allows you to do the following three things:

• .next() - Push new data into the component's Inputs, as well as provide callbacks for the Outputs. This is how you pass new down into the created component.
• .detach() - Allows you to detach the component from the DOM as well as destroys the component. This is how you destroy the created component.
• .componentRef - This is a pointer to the created component. This is of type ComponentRef. In other words, this is the instance of the component that is returned when you call new on the class definition. The .componentRef is the this of the component.

How to use it

Installation

Start by installing it correctly:

npm install @herodevs/dynamic-af

Inject the Service

Now you need to inject the service into your component, or into another service of your own. You do that by adding it to the constructor of your component/service, like so:

export class MyCoolComponent {
  constructor(private dynamicService: DynamicComponentService) {
    // ...
  }
}

Call createAndAttachComponentSync

Now that you have the service, you can call the createAndAttachComponentSync method to create a component and have it attached to the DOM. Here is an example of what that looks like:

const ref = dynamicService.createAndAttachComponentSync(FooComponent, { vcr: this.viewContainerRef });

You must pass the createAndAttachComponentSync method two parameters. First, you need to pass the class of the component that you want to dynamically create. The second is an object that matches the CreateComponentOptions interface:

interface CreateComponentOptions {
  module?: NgModuleRef<any>;
  context?: { [key: string]: any };
  vcr?: ViewContainerRef;
}

Here are what each of those represents:

• vcr (optional, but not really) - This is the ViewContainerRef where you want to attach the createdComponent. If you don't provide a vcr, the service will have no choice but to attach your component to the bottom of the document.body. So it is recommended that you DEFINITELY provide a vcr.
• context (optional) - This is an object that has keys that match the names of the Inputs/Outputs of the component being created. If your component being created has an input named name, then you can pass a context with a name property to provide a name. Eg: {name: 'Your Name'}. This will pass the value Your Name into the Input of you component.
• module (optional) - This is a reference to the module that the component belongs to. You only need to pass this if you manually lazily loaded the component and module. Otherwise you can not pass this.

Updating input/output values

Once you have the ref to your created component, you can call next(newContext) to pass in new values to your inputs/outputs of your component. Here is an example of updating an input value one second for a component that has @Input() count:

const ref = dynamicService.createAndAttachComponentSync(FooComponent, { vcr: this.viewContainerRef });

let count = 0;
ref.next({ count: count++ });

setInterval(() => {
  ref.next({ count: count++ });
}, 1000);

Once a second the created component will get a new count via it's input.