Dependency injection

All you need is the @autoinject annotation. The JS/HTML mapping is performed automatically by the framework:

class Ticket { /* class code, properties, methods... */ }

@inject
export class Sale {
    constructor( ticket ) {}

    public activate() {
        // do something...
        this.ticket.toast("Sale processed!");
    }
}

For Typescript users, the annotation names are very similar. Use @autoinject instead of @inject and don't forget to specify the visibility and type of object in the constructor : constructor(private ticket : Ticket)