Web Components Banner | Infragistics

The Ignite UI for Web Components Banner component provides a way to easily display a prominent message to your application's users in a way that is less transient than a snackbar and less obtrusive than a dialog. It can also indicate actions to take based on the context of the message.

Usage

First, you need to install the Ignite UI for Web Components by running the following command:

npm install igniteui-webcomponents

You will then need to import the IgcBannerComponent, its necessary CSS, and register its module, like so:

import { defineComponents, IgcBannerComponent } from "igniteui-webcomponents";
import 'igniteui-webcomponents/themes/light/bootstrap.css';

defineComponents(IgcBannerComponent);

For a complete introduction to the Ignite UI for Web Components, read the Getting Started topic.

In order to display the banner component, use its show method and call it on a button click. The banner appears relative to where the element was inserted in the page template, moving all other content. It typically shows some non-intrusive content that requires minimal user interaction to be dismissed.

<igc-button onclick="banner.show()">Show Banner</igc-button>

<igc-banner id="banner">
    You are currently offline.
</igc-banner>

[!NOTE] The IgcBannerComponent includes a default action button OK, which closes the banner.

Examples

The IgcBannerComponent component allows templating of its content while still sticking as closely as possible to the material design banner guidelines.

Changing the banner message

Configuring the message displayed in the banner is easy - just change the content you are passing to the igc-banner tag. The text will show up in the specified banner area and the banner will use its default template when displaying it. Below, we will change the content of our sample banner to be a bit more descriptive:

<igc-banner id="banner">
    You have lost connection to the internet. This app is offline.
</igc-banner>

Adding an icon

An IgcIconComponent can be displayed in the banner by using the banner's prefix slot. The icon will always be positioned at the beginning of the banner message.

[!NOTE] If several IgcIconComponent elements are inserted, the banner will try to position all of them at the beginning. It is strongly advised to pass only one IgcIconComponent directly to the banner.

To pass an IgcIconComponent to your banner, use the prefix slot:

<igc-banner id="banner">
    <igc-icon slot="prefix" name="signal_wifi_off"></igc-icon>
    You have lost connection to the internet. This app is offline.
</igc-banner>

If you want to use an IgcIconComponent in your banner message, simply insert it in the banner's content:

<igc-banner id="banner">
    You have lost connection to the internet. This app is offline.
    <igc-icon name="signal_wifi_off"></igc-icon>
</igc-banner>

The IgcBannerComponent exposes the actions slot for templating the banner buttons. This allows you to override the default banner button (OK) and add user-defined custom actions.

<igc-banner id="banner">
    <igc-icon slot="prefix" name="signal_wifi_off"></igc-icon>
    You have lost connection to the internet. This app is offline.
    <div slot="actions">
        <igc-button onclick="banner.toggle()">
            <igc-ripple></igc-ripple>
            Toggle Banner
        </igc-button>
    </div>
</igc-banner>

Binding to events

The banner component emits the igcClosing and igcClosed events when being closed. The igcClosing event is cancelable - it uses the CustomEvent interface and the emitted object has its cancelable property set to true. If we cancel the igcClosing event, the corresponding end action and event will not be triggered - the banner will not be closed and the igcClosed event will not be emitted.

To cancel the closing event, call the preventDefault method.

<igc-banner id="banner">
    ...
</igc-banner>

const banner = document.getElementById('banner') as IgcBannerComponent;

banner.addEventListener('igcClosing', (event) => {
  event.preventDefault();
});

[!NOTE] If the changes above are applied, the banner will never close, as the closing event is always cancelled.

Advanced Example

Let's create a banner with two custom buttons - one for dismissing the notification and one for turning on the connection. We can pass custom action handlers using the actions slot:

<igc-banner id="banner">
    <igc-icon slot="prefix" name="signal_wifi_off"></igc-icon>
    You have lost connection to the internet. This app is offline.
    <div slot="actions">
        <igc-button onclick="banner.hide()">
            <igc-ripple></igc-ripple>
            Continue Offline
        </igc-button>
        <igc-button id="button">
            <igc-ripple></igc-ripple>
            Turn On Wifi
        </igc-button>
    </div>
</igc-banner>

According to Google's Material Design guidelines, a banner should have a maximum of 2 buttons present. The IgcBannerComponent does not explicitly limit the number of elements under the actions slot, but it is strongly recommended to use up to 2 if you want to adhere to the material design guidelines.

The dismiss option (Continue Offline) doesn't need any further logic, so it can just call the hide method. The confirm action (Turn On Wifi), however, requires some additional logic, so we have to define it in the component. Then, we will add an event listener for the click event. The last step is to call the refreshBanner() method on each change, which will toggle the banner depending on the wifiState.

The navbar will have a Wifi icon and we will add an event listener for its click event as well. As the refreshBanner() method is called on each change, the icon will not only toggle the banner, but change according to the state of the connection:

<igc-navbar>
  <h1>Gallery</h1>
  <igc-icon id="icon" slot="end" name="signal_wifi_off"></igc-icon>
</igc-navbar>

<igc-banner id="banner">
    ...
    <div slot="actions">
        ...
        <igc-button id="button">
            <igc-ripple></igc-ripple>
            Turn On Wifi
        </igc-button>
    </div>
</igc-banner>

private banner: IgcBannerComponent;
private icon: IgcIconComponent;
private button: IgcButtonComponent;

private wifiState: boolean = false;

constructor() {
    this.banner = document.getElementById('banner') as IgcBannerComponent;
    this.icon = document.getElementById('icon') as IgcIconComponent;
    this.button = document.getElementById('button') as IgcButtonComponent;

    this.icon.addEventListener('click', () => this.refreshBanner());
    this.button.addEventListener('click', () => this.refreshBanner());
}

public refreshBanner() {
    if (!this.wifiState) {
        this.icon.name = 'signal_wifi_4_bar';
        this.banner.hide();
    } else {
        this.icon.name = 'signal_wifi_off';
        this.banner.show();
    }
    this.wifiState = !this.wifiState;
}

Finally, we will add a IgcToastComponent, displaying a message about the WiFi state. The results of the templated banner can be seen in the demo below:

Styling

The banner component exposes several CSS parts (base, spacer, message, illustration, content and actions) to give you full control over its style.

igc-banner::part(spacer) {
    background: #dedede;
}

igc-banner::part(illustration) {
    color: #666666;
}

igc-banner::part(content) {
    color: #151515;
}

Web Components Banner Overview

Ignite UI for Web Components Banner Example

Usage

Show Banner

Examples

Changing the banner message

Adding an icon

Changing the banner button

Binding to events

Advanced Example

Styling

API References

Additional Resources