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Bootstrap/site/content/docs/5.0/components/buttons.md
Patrick H. Lauke 0a6cf9036c
Docs: improve/expand button documentation (#31093)
* Docs: improve/expand button documentation

- since we're not doing the disabled cursor thing anymore anyway, remove confusing/unnecessary mention for link-based disabled buttons
- make the disabled toggle example using a link actually follow the preceding advice of also having `tabindex="-1"` and `aria-disabled="true"`
- tweak the link functionality callout to also still mention `aria-disabled` to reinforce the idea
- tweak toggle state description (not just `<button>`s, but also links etc...so just remove mention of `<button>` there; also reinforce accessibility aspect once more)
- add a new callout that cross-references checkbox-based toggles, and what the similarity/difference between them is
- add a matching cross-reference callout to the checkbox-based toggle buttons page

* Update link to now renamed checks-radios.md
2020-07-03 12:34:32 +01:00

7.4 KiB

layout title description group toc
docs Buttons Use Bootstrap's custom button styles for actions in forms, dialogs, and more with support for multiple sizes, states, and more. components true

Examples

Bootstrap includes several predefined button styles, each serving its own semantic purpose, with a few extras thrown in for more control.

{{< example >}} {{< buttons.inline >}} {{- range (index $.Site.Data "theme-colors") }} {{ .name | title }} {{- end -}} {{< /buttons.inline >}}

Link {{< /example >}}

{{< callout info >}} {{< partial "callout-warning-color-assistive-technologies.md" >}} {{< /callout >}}

Disable text wrapping

If you don't want the button text to wrap, you can add the .text-nowrap class to the button. In Sass, you can set $btn-white-space: nowrap to disable text wrapping for each button.

Button tags

The .btn classes are designed to be used with the <button> element. However, you can also use these classes on <a> or <input> elements (though some browsers may apply a slightly different rendering).

When using button classes on <a> elements that are used to trigger in-page functionality (like collapsing content), rather than linking to new pages or sections within the current page, these links should be given a role="button" to appropriately convey their purpose to assistive technologies such as screen readers.

{{< example >}} Link Button {{< /example >}}

Outline buttons

In need of a button, but not the hefty background colors they bring? Replace the default modifier classes with the .btn-outline-* ones to remove all background images and colors on any button.

{{< example >}} {{< buttons.inline >}} {{- range (index $.Site.Data "theme-colors") }} {{ .name | title }} {{- end -}} {{< /buttons.inline >}} {{< /example >}}

Sizes

Fancy larger or smaller buttons? Add .btn-lg or .btn-sm for additional sizes.

{{< example >}} Large button Large button {{< /example >}}

{{< example >}} Small button Small button {{< /example >}}

Create block level buttons—those that span the full width of a parent—by adding .btn-block.

{{< example >}} Block level button Block level button {{< /example >}}

Disabled state

Make buttons look inactive by adding the disabled boolean attribute to any <button> element. Disabled buttons have pointer-events: none applied to, preventing hover and active states from triggering.

{{< example >}} Primary button Button {{< /example >}}

Disabled buttons using the <a> element behave a bit different:

  • <a>s don't support the disabled attribute, so you must add the .disabled class to make it visually appear disabled.
  • Some future-friendly styles are included to disable all pointer-events on anchor buttons.
  • Disabled buttons should include the aria-disabled="true" attribute to indicate the state of the element to assistive technologies.

{{< example >}} Primary link Link {{< /example >}}

{{< callout warning >}}

The .disabled class uses pointer-events: none to try to disable the link functionality of <a>s, but that CSS property is not yet standardized. In addition, even in browsers that do support pointer-events: none, keyboard navigation remains unaffected, meaning that sighted keyboard users and users of assistive technologies will still be able to activate these links. So to be safe, in addition to aria-disabled="true", also include a tabindex="-1" attribute on these links to prevent them from receiving keyboard focus, and use custom JavaScript to disable their functionality altogether. {{< /callout >}}

Button plugin

The button plugin allows you to create simple on/off toggle buttons.

{{< callout info >}} Visually, these toggle buttons are identical to the [checkbox toggle buttons]({{< docsref "/forms/checks-radios#checkbox-toggle-buttons" >}}). However, they are conveyed differently by assistive technologies: the checkbox toggles will be announced by screen readers as "checked"/"not checked" (since, despite their appearance, they are fundamentally still checkboxes), whereas these toggle buttons will be announced as "button"/"button pressed". The choice between these two approaches will depend on the type of toggle you are creating, and whether or not the toggle will make sense to users when announced as a checkbox or as an actual button. {{< /callout >}}

Toggle states

Add data-toggle="button" to toggle a button's active state. If you're pre-toggling a button, you must manually add the .active class and aria-pressed="true" to ensure that it is conveyed appropriately to assistive technologies.

{{< example >}} Toggle button Active toggle button Disabled toggle button {{< /example >}}

{{< example >}} Toggle link Active toggle link Disabled toggle link {{< /example >}}

Methods

You can create a button instance with the button constructor, for example:

{{< highlight js >}} var button = document.getElementById('myButton') var bsButton = new bootstrap.Button(button) {{< /highlight >}}

Method Description
toggle Toggles push state. Gives the button the appearance that it has been activated.
dispose Destroys an element's button.

For example, to toggle all buttons

{{< highlight js >}} var buttons = document.querySelectorAll('.btn') buttons.forEach(function (button) { var button = new bootstrap.Button(button) button.toggle() }) {{< /highlight >}}