Transcluding Angular 2 Components into Angular 1 Directives

Angular 2 components can be transcluded into Angular 1.x directives.

Here is a very simple Angular 2 component:

import {Component} from '@angular/core';
@Component ({
selector: 'a2-transclusion-contents',
template: `<p>{{ message }}</p>`
})
export class A2Transclusion {
message =
'I am an Angular 2 Component "transcluded" into Angular 1.x';
}

Here is an Angular 1.x directive that supports transclusion:

export function a1TransclusionDirective() {
return {
restrict: 'E',
transclude: true,
scope: {},
bindToController: {},
controller: A1Transclusion,
controllerAs: 'a1ProjectionContents',
template: `
<p>
<ng-transclude></ng-transclude>
</p>
`
};
}
class A1Transclusion {
}

Angular 1.x needs to know about both the component and the directive:

import {A2Transclusion} from './components/a2-transclusion-contents';
import {a1TransclusionDirective} from './components/a1-transclusion';
// Angular 1 Vendor Import
import * as angular from 'angular';
// Import the upgradeAdapter singleton
import {upgradeAdapter} from './upgrade-adapter';
// Name the application
const APPNAME = 'angular-upgrade-example';
// Register classic Angular 1 modules
angular
.module(APPNAME)
.directive('a2TransclusionContents',
upgradeAdapter.downgradeNg2Component(A2Transclusion))
.directive('a1Transclusion', a1TransclusionDirective);

Finally, Angular 2 content can be transcluded into Angular 1.x like so:

<a1-transclude>
<a2-transclusion-contents></a2-transclusion-contents>
</a1-transclude>