NativeScript Typings

Question

I'm working through the NativeScript getting started tutorial in TypeScript: http://developer.telerik.com/featured/getting-started-nativescript/

In one snippet of code, I see:

exports.loadSignUpView = function(args) {
    page = args.object;

    page.bindingContext = journeyInfo;
}

After some research I was able to type args as

import app = require("application");
exports.loadSignUpView = function(args: app.ApplicationEventData) {
     //...
}

But that still does not help me type the page object above, which has the bindingContext property. What is the TypeScript type that corresponds to the page?

Answer 1

Page type is defined in the "ui/page" module and the type of the args of the loaded event is EventData (from the "data/observable" module). So you can do something like this:

import observable = require("data/observable");
import pages = require("ui/page");

// Event handler for Page "loaded" event attached in main-page.xml
export function loadSignUpView (args: observable.EventData) {
    // Get the event sender
    var page = <pages.Page>args.object;
}

Few more useful tips to get you started:

1. NativeScript has TypeScript support build in since the 1.5 release . You can now use the NativeScript CLI to setup typescript project. You can check the documentation for more.
2. In the documentation there is more up to date getting-started guide
3. All of the code snippets in the docs have also a TypeScript version so that you can see the typings there - we love typescript ;)