Bootstrap/site/docs/4.3/components/alerts.md

layout	title	description	group	redirect_from	toc
docs	Alerts	Provide contextual feedback messages for typical user actions with the handful of available and flexible alert messages.	components	/components/ /docs/4.3/components/	true

Examples

Alerts are available for any length of text, as well as an optional dismiss button. For proper styling, use one of the eight required contextual classes (e.g., .alert-success). For inline dismissal, use the alerts JavaScript plugin.

{% capture example %} {% for color in site.data.theme-colors %}

A simple {{ color.name }} alert—check it out!

{% endfor %} {% endcapture %} {% include example.html content=example %}

{% include callout-warning-color-assistive-technologies.md %}

Link color

Use the .alert-link utility class to quickly provide matching colored links within any alert.

{% capture example %} {% for color in site.data.theme-colors %}

A simple {{ color.name }} alert with an example link. Give it a click if you like.

{% endfor %} {% endcapture %} {% include example.html content=example %}

Additional content

Alerts can also contain additional HTML elements like headings, paragraphs and dividers.

{% capture example %}

Well done!

Aww yeah, you successfully read this important alert message. This example text is going to run a bit longer so that you can see how spacing within an alert works with this kind of content.

---

Whenever you need to, be sure to use margin utilities to keep things nice and tidy.

{% endcapture %} {% include example.html content=example %}

Dismissing

Using the alert JavaScript plugin, it's possible to dismiss any alert inline. Here's how:

• Be sure you've loaded the alert plugin, or the compiled Bootstrap JavaScript.
• If you're building our JavaScript from source, it [requires util.js]({{ site.baseurl }}/docs/{{ site.docs_version }}/getting-started/javascript/#util). The compiled version includes this.
• Add a dismiss button and the .alert-dismissible class, which adds extra padding to the right of the alert and positions the .close button.
• On the dismiss button, add the data-dismiss="alert" attribute, which triggers the JavaScript functionality. Be sure to use the <button> element with it for proper behavior across all devices.
• To animate alerts when dismissing them, be sure to add the .fade and .show classes.

You can see this in action with a live demo:

{% capture example %}

Holy guacamole! You should check in on some of those fields below. ×

{% endcapture %} {% include example.html content=example %}

JavaScript behavior

Triggers

Enable dismissal of an alert via JavaScript:

{% highlight js %} var alertList = document.querySelectorAll('.alert') alertList.forEach(function (alert) { new bootstrap.Alert(alert) }) {% endhighlight %}

Or with data attributes on a button within the alert, as demonstrated above:

{% highlight html %} × {% endhighlight %}

Note that closing an alert will remove it from the DOM.

Methods

You can create an alert instance with the alert constructor, for example:

{% highlight js %} var myAlert = document.getElementById('myAlert') var bsAlert = new bootstrap.Alert(myAlert) {% endhighlight %}

This makes an alert listen for click events on descendant elements which have the data-dismiss="alert" attribute. (Not necessary when using the data-api's auto-initialization.)

Method	Description
close	Closes an alert by removing it from the DOM. If the .fade and .show classes are present on the element, the alert will fade out before it is removed.
dispose	Destroys an element's alert.
_getInstance	Static method which allows you to get the alert instance associated to a DOM element, you can use it like this: bootstrap.Alert._getInstance(alert)

{% highlight js %} var alertNode = document.querySelector('.alert') var alert = bootstrap.Alert._getInstance(alertNode) alert.close() {% endhighlight %}

Events

Bootstrap's alert plugin exposes a few events for hooking into alert functionality.

Event	Description
close.bs.alert	This event fires immediately when the close instance method is called.
closed.bs.alert	This event is fired when the alert has been closed (will wait for CSS transitions to complete).

{% highlight js %} var myAlert = document.getElementById('myAlert') myAlert.addEventListener('closed.bs.alert', function () { // do something… }) {% endhighlight %}