---
title: Angular 2
order: 2
layout: page
---

[[vaadin-core-elements.angular2]]
= Angular 2 Integration

While Vaadin Elements are built using Polymer, they also contain directives to enable seamless usage within Angular 2 applications.
This page assumes that you already have an Angular 2 application setup ready.
If you need help with the project setup, you should follow the https://angular.io/docs/ts/latest/quickstart.html[Angular 2 Quickstart] guide.

== Installation

Although Angular 2 dependecies are typically installed via https://www.npmjs.com/[npm], Vaadin Elements require installation with http://bower.io[Bower].
To install a Vaadin Core Element, you should run the following command in your project directory (replace the `[element-name]` part with the actual name of the element).

[NOTE]
Angular 2 support was introduced in `1.1.0-alpha1` versions of each element.
Minimum requirement for the Angular version is `2.0.0-beta.16` or newer.

[source,bash]
----
bower install --save vaadin-[element-name]#1.1.0-alpha1
----

After the Bower installation is completed, you need to add the Web Components polyfill to the `<head>` section of your `index.html` file.
[source,html]
----
<script src="bower_components/webcomponentsjs/webcomponents-lite.min.js"></script>
----

The Web Components polyfill will enable usage of HTML imports in your application.
In order to have the newly installed Vaadin element available in your templates, you need to add an import for it.

[source,html]
----
<link rel="import" href="bower_components/vaadin-[element-name]/vaadin-[element-name].html">
----

Also the SystemJS configuration needs some modifications in order to load the modules correctly.
Add the following `packages` entry for `bower_components` to your configuration unless it’s already present.

[source,javascript]
----
System.config({
  packages: {
    'bower_components': {
      defaultExtension: 'js'
    }
  }
});
----

Before bootstrapping your application, you need to wait for the `WebComponentsReady` event.
This event is fired after the HTML imports are done and the custom elements are upgraded and ready to be used.
The following example demonstrates how to wrap your bootstrap code inside the event listener.

[source,javascript]
----
window.addEventListener('WebComponentsReady', function() {
  System.import('app/main').then(null, console.error.bind(console));
});
----

[NOTE]
If you see errors about missing behaviors in the console, please visit this [known issue](https://github.com/vaadin/vaadin-core-elements/issues/46)

Now you’re all set to use the element inside your Angular 2 application.

== Importing

Import the directive as follows. This example imports the [vaadinelement]#vaadin-date-picker# element, but you should replace the path with the element you’re importing.
Also the directive name should be replaced with a camel case representation of the element name.

[source,javascript]
----
import { VaadinDatePicker } from '../bower_components/vaadin-date-picker/directives/vaadin-date-picker';
----

Your Angular 2 component also needs to declare the usage of the directive.
This can be done with the `directives` array of the `@Component` decorator.
After the directive is declared, the element is available to be used in the `template` of your component.

[source]
----
@Component({
  selector: 'my-component',
  template: '<vaadin-date-picker [(value)]="birthDay"></vaadin-date-picker>',
  directives: [VaadinDatePicker]
})
----

Notice that for Vaadin Charts, you also need to import and declare the `DataSeries` directive as follows.

[source]
----
import { VaadinCharts, DataSeries } from '../bower_components/vaadin-charts/directives/vaadin-charts';

@Component({
  selector: 'my-component',
  template: `
    <vaadin-area-chart>
      <title>Fibonacci</title>
      <x-axis><title>Index</title></x-axis>
      <y-axis><title>Value</title></y-axis>
      <data-series>
        <data>1, 1, 2, 3, 5, 8, 13, 21, 34</data>
      </data-series>
    </vaadin-area-chart>`,
  directives: [VaadinCharts, DataSeries]
})
----

== Usage
For the most part you can use the API provided by the element.
This API is described in the documentation of each individual element.
Most notable changes introduced by the directives are the support for data-binding using the Angular 2 syntax and integration with the https://angular.io/docs/ts/latest/guide/forms.html[Angular forms].

=== Data-Binding
You can use Angular 2 data-binding syntax with all the properties declared in the API documentation for each element.
Some properties also support two-way data-binding. These are marked with [propertyname]#notifies# in the API documentation.

[source]
----
<vaadin-combo-box
  label="My ComboBox"
  [(value)]="myValue"
  [items]="myItems">
</vaadin-combo-box>
----


=== Form Controls
When using input-like elements ([elementname]#vaadin-combo-box#, [elementname]#vaadin-date-picker# or [elementname]#vaadin-upload#) inside an Angular form, you should normally use the [propertyname]#ngControl# attribute to track the state and validity.
You can use two-way data-binding with [propertyname]#ngModel# as you would with other form fields.
Simple validation like the [propertyname]#required# validator is supported as well as defining custom validators.

See the example below on how to use [elementname]#vaadin-combo-box# as a form control with data-bound [propertyname]#items# property.
[source]
----
<vaadin-combo-box
  label="My ComboBox"
  [(ngModel)]="myValue"
  [items]="myItems"
  ngControl="myCombo"
  required>
</vaadin-combo-box>
----

=== Styling
Due to the Shadow DOM encapsulation, applying normal CSS rules for a Vaadin Element is limited to the main element only.

Therefore, in order to fully customize the appearance of Vaadin Elements, you need to use https://www.polymer-project.org/1.0/docs/devguide/styling.html#xscope-styling-details[CSS properties] and https://www.polymer-project.org/1.0/docs/devguide/styling.html#custom-css-mixins[CSS mixins].
Unfortunately these styles cannot be applied on a component level, but instead you need to provide styles in application level and also use the `is="custom-style"` attribute.

Changing the icon color of [vaadinelement]#vaadin-date-picker# to `red` could be done with the following example.
[source]
----
<style is="custom-style">
  vaadin-date-picker {
    --vaadin-date-picker-calendar-icon: {
      fill: red;
    }
  }
</style>
----

See the documentation of each element for a list of available properties and mixins.

=== Grid
The [elementname]#vaadin-grid# element uses a `table` child element to declaratively configure columns, headers and footers.
In case you’ll need to apply modifications to the declaratively configured [elementname]#vaadin-grid# columns, you must wait for the component to be fully initialized first.
To do this, you should use the `grid-ready` event as follows.

[source]
----
<vaadin-grid (grid-ready)="gridReady($event)" [items]="dataItems">
  <table>
    <colgroup>
      <col>
    </colgroup>
  </table>
</vaadin-grid>
----
[source, javascript]
----
gridReady(grid) {
  // You can now configure the columns by adding a renderer function for example.
  grid.columns[0].renderer = (cell) => {
    cell.element.innerHTML = 'row-' + cell.row.index;
  }
}
----
