NativeScript/tns-core-modules/ui/placeholder/placeholder.ts

import { Placeholder as PlaceholderDefinition, CreateViewEventData } from ".";
import { View, EventData } from "../core/view";

export class Placeholder extends View implements PlaceholderDefinition {
    public static creatingViewEvent = "creatingView";

    public createNativeView() {
        const args = <CreateViewEventData>{ eventName: Placeholder.creatingViewEvent, object: this, view: undefined, context: this._context };
        this.notify(args);

        return args.view;
    }
}
export interface Placeholder {
    on(eventNames: string, callback: (args: EventData) => void);
    on(event: "creatingView", callback: (args: CreateViewEventData) => void);
}