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Bootstrap/site/docs/4.3/components/buttons.md
Patrick H. Lauke be80d26cdb Ensure button plugin sets/removes active class correctly on page load (#28952)
* Ensure correct active class is set on button toggles/checkboxes/radios on page load

Sanity check, ensures that the UI visually matches the actual values/states of controls. Also ensures that if any autocomplete/autofill happened, this is visually accounted for
by having the correct class set.

Includes unit tests (and `autocomplete` has been removed from these as it's no longer necessary)

* Remove now unnecessary autocomplete attribute

As the attribute was there to force/ensure that the visual presentation matched the state, and this is now taken care of programmatically, there's no need to unnecessarily suppress autocomplete...let them autocomplete if they want to...
2019-07-10 11:03:54 +03:00

7.7 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.

{% capture example %} {% for color in site.data.theme-colors %} {{ color.name | capitalize }}{% endfor %}

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

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

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.

{% capture example %} Link Button {% endcapture %} {% include example.html content=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.

{% capture example %} {% for color in site.data.theme-colors %} {{ color.name | capitalize }}{% endfor %} {% endcapture %} {% include example.html content=example %}

Sizes

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

{% capture example %} Large button Large button {% endcapture %} {% include example.html content=example %}

{% capture example %} Small button Small button {% endcapture %} {% include example.html content=example %}

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

{% capture example %} Block level button Block level button {% endcapture %} {% include example.html content=example %}

Active state

Buttons will appear pressed (with a darker background, darker border, and inset shadow) when active. There's no need to add a class to <button>s as they use a pseudo-class. However, you can still force the same active appearance with .active (and include the aria-pressed="true" attribute) should you need to replicate the state programmatically.

{% capture example %} Primary link Link {% endcapture %} {% include example.html content=example %}

Disabled state

Make buttons look inactive by adding the disabled boolean attribute to any <button> element.

{% capture example %} Primary button Button {% endcapture %} {% include example.html content=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. In browsers which support that property, you won't see the disabled cursor at all.
  • Disabled buttons should include the aria-disabled="true" attribute to indicate the state of the element to assistive technologies.

{% capture example %} Primary link Link {% endcapture %} {% include example.html content=example %}

{% capture callout %}

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, add a tabindex="-1" attribute on these links (to prevent them from receiving keyboard focus) and use custom JavaScript to disable their functionality. {% endcapture %} {% include callout.html content=callout type="warning" %}

Button plugin

Do more with buttons. Control button states or create groups of buttons for more components like toolbars.

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 the <button>.

{% capture example %} Single toggle {% endcapture %} {% include example.html content=example %}

Checkbox and radio buttons

Bootstrap's .button styles can be applied to other elements, such as <label>s, to provide checkbox or radio style button toggling. Add data-toggle="buttons" to a .btn-group containing those modified buttons to enable their toggling behavior via JavaScript and add .btn-group-toggle to style the <input>s within your buttons. Note that you can create single input-powered buttons or groups of them.

The checked state for these buttons is only updated via click event on the button. If you use another method to update the input—e.g., with <input type="reset"> or by manually applying the input's checked property—you'll need to toggle .active on the <label> manually.

Note that pre-checked buttons require you to manually add the .active class to the input's <label>.

{% capture example %}

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

{% capture example %}

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

Methods

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