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layout | title | description | group | aliases | toc | ||
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docs | Alerts | Provide contextual feedback messages for typical user actions with the handful of available and flexible alert messages. | components |
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true |
Examples
Alerts are available for any length of text, as well as an optional close button. For proper styling, use one of the eight required contextual classes (e.g., .alert-success
). For inline dismissal, use the alerts JavaScript plugin.
{{< example >}} {{< alerts.inline >}} {{- range (index $.Site.Data "theme-colors") }}
{{< callout info >}} {{< partial "callout-warning-color-assistive-technologies.md" >}} {{< /callout >}}
Link color
Use the .alert-link
utility class to quickly provide matching colored links within any alert.
{{< example >}} {{< alerts.inline >}} {{- range (index $.Site.Data "theme-colors") }}
Additional content
Alerts can also contain additional HTML elements like headings, paragraphs and dividers.
{{< 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.
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.
- Add a [close button]({{< docsref "/components/close-button" >}}) and the
.alert-dismissible
class, which adds extra padding to the right of the alert and positions the close button. - On the close 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:
{{< example >}}
{{< callout warning >}}
When an alert is dismissed, the element is completely removed from the page structure. If a keyboard user dismisses the alert using the close button, their focus will suddenly be lost and, depending on the browser, reset to the start of the page/document. For this reason, we recommend including additional JavaScript that listens for the closed.bs.alert
event and programmatically sets focus()
to the most appropriate location in the page. If you're planning to move focus to a non-interactive element that normally does not receive focus, make sure to add tabindex="-1"
to the element.
{{< /callout >}}
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) }) {{< /highlight >}}
Or with data
attributes on a button within the alert, as demonstrated above:
{{< highlight html >}} {{< /highlight >}}
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) {{< /highlight >}}
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() {{< /highlight >}}
Events
Bootstrap's alert plugin exposes a few events for hooking into alert functionality.
Event | Description |
---|---|
close.bs.alert |
Fires immediately when the close instance method is called.
|
closed.bs.alert |
Fired when the alert has been closed and CSS transitions have completed. |
{{< highlight js >}} var myAlert = document.getElementById('myAlert') myAlert.addEventListener('closed.bs.alert', function () { // do something … for instance, explicitly move focus to the most appropriate element, // so it doesn't get lost/reset to the start of the page // document.getElementById('…').focus() }) {{< /highlight >}}