Q: Typescript function not being run I have the following typescript file in Nativescript:
import { Observable } from 'tns-core-modules/data/observable';
import { isIOS } from "tns-core-modules/platform";
import { Color } from "tns-core-modules/color";
import { request, getFile, getImage, getJSON, getString } from "tns-core-modules/http";

export class HomeViewModel extends Observable {

    items: {
        name: string,
        desc: string, 
        price: string, 
        imageSrc: string, 
     }[];

    getData = getJSON("http://localhost:3000/items").then((r: any) => {
        this.getData = r; // assign it from the response when successful
            console.log("blarg!!!")
        }, (e) => {
    }); 

    onItemLoading(args) {
        // hack to get around issue with RadListView ios background colors: https://github.com/telerik/nativescript-ui-feedback/issues/196
        if (isIOS) {
            var newcolor = new Color("#e6e6e6");
            args.ios.backgroundView.backgroundColor = newcolor.ios;
        }
    }

    constructor() {
        super();
    }
}

The issue I am seeing is that getData is never being called/ran. How do I call/run the getData function?

A: This is really not type-safe and you probably don't mean to do this.
getData = getJSON("http://localhost:3000/items").then((r: any) => {
    this.getData = r; // assign it from the response when successful
        console.log("blarg!!!")
    }, (e) => {
}); 

If you expose the type from the initial assignment, you've got:
getData: Promise<void> = ...

If you expose the type from the inner assignment, you've got:
this.getData = r as any;

It is very likely that neither of these is actually a function. Instead, what you probably wanted to do was something more along the lines of:
data: any;

constructor() {
    super();

    getJSON("http://localhost:3000/items").then((r: any) => {
        this.data = r; // assign it from the response when successful
            console.log("blarg!!!")
        }, (e) => {
    });
}


A: You need to call it higher up the stack. Or, If you want getData to run when the object is created, call getData() in your constructor.
