[TIMOB-25890] Windows: Support ES6 imports

[infosia]

TIMOB-25890

Enable use of ES6-style imports for Windows.

// ES5-style require call
var Int32 = require('System.Int32');

// ES6-style import
import Button from 'Windows.UI.Xaml.Controls.Button';
import PropertyValue from 'Windows.Foundation.PropertyValue';
import MessageDialog from 'Windows.UI.Popups.MessageDialog';
import UICommand from 'Windows.UI.Popups.UICommand';

let win = Ti.UI.createWindow({ backgroundColor: 'green' }),
	button = new Button();

button.Content = "PUSH";
button.addEventListener('Tapped', () => {
    const dialog = new MessageDialog('My Message');
    dialog.Title = 'My Title';
    dialog.DefaultCommandIndex = 0;
    dialog.Commands.Add(new UICommand('OK', null, PropertyValue.CreateInt32(0)));
    dialog.Commands.Add(new UICommand('Cancel', null, PropertyValue.CreateInt32(1)));
    dialog.ShowAsync().then(function (command) {
        const id = Int32.cast(command.Id);
        alert((id == 0) ? 'Pushed "OK"' : 'Pushed "Cancel"')
    });
});

win.add(button);
win.open();

[hansemannn]

Does the following statements work as well (for parity with iOS and Android)?

import { MessageDialog, UICommand } from 'Windows.UI.Popups';

[infosia]

@hansemannn Currently, import { MessageDialog, UICommand } from 'Windows.UI.Popups'; is not supported because in this case resulting code will be transpiled into require(package_name) such as;

var Popups = require('Windows.UI.Popups'); 
var MessageDialog = Popups.MessageDialog.

This doesn't work because Hyperloop Windows require needs fully qualified class name or enum and require against package name is not implemented yet. I don't expect this is going to be few-hours work so I'm going look into this in separate ticket.

[hansemannn]

Ok. Is the PR ready for review then?

[infosia]

Yes 👍

[hansemannn]

@infosia I am wondering if we can move the Windows hooks to ES6 as well. @sgtcoolguy made huge refactoring progress in #271, but Windows haven't been touched so far. Of course this has no immediate priority!

[hansemannn]

Asking @sgtcoolguy for review as he did something very similar on #270.

[infosia]

@hansemannn FYI I'm planning to implement multiple imports like below, which looks similar to android implementation. I would like to do like this because this makes the internal implementation simpler and easier as ".*" clearly indicates this is a package name.

import { MessageDialog, UICommand } from 'Windows.UI.Popups.*';