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Bootstrap/site/content/docs/4.3/components/buttons.md
2019-10-25 12:37:52 +03:00

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---
layout: docs
title: Buttons
description: Use Bootstrap's custom button styles for actions in forms, dialogs, and more with support for multiple sizes, states, and more.
group: components
toc: 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 $.Site.Data "theme-colors") }}
<button type="button" class="btn btn-{{ .name }}">{{ .name | title }}</button>
{{- end -}}
{{< /buttons.inline >}}
<button type="button" class="btn btn-link">Link</button>
{{< /example >}}
{{< callout info >}}
{{< partial "callout-warning-color-assistive-technologies.md" >}}
{{< /callout >}}
## Disable text wrapping
If you don't want the button text to wrap, you can add the `.text-nowrap` class to the button. In Sass, you can set `$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 >}}
<a class="btn btn-primary" href="#" role="button">Link</a>
<button class="btn btn-primary" type="submit">Button</button>
<input class="btn btn-primary" type="button" value="Input">
<input class="btn btn-primary" type="submit" value="Submit">
<input class="btn btn-primary" type="reset" value="Reset">
{{< /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") }}
<button type="button" class="btn btn-outline-{{ .name }}">{{ .name | title }}</button>
{{- end -}}
{{< /buttons.inline >}}
{{< /example >}}
## Sizes
Fancy larger or smaller buttons? Add `.btn-lg` or `.btn-sm` for additional sizes.
{{< example >}}
<button type="button" class="btn btn-primary btn-lg">Large button</button>
<button type="button" class="btn btn-secondary btn-lg">Large button</button>
{{< /example >}}
{{< example >}}
<button type="button" class="btn btn-primary btn-sm">Small button</button>
<button type="button" class="btn btn-secondary btn-sm">Small button</button>
{{< /example >}}
Create block level buttons—those that span the full width of a parent—by adding `.btn-block`.
{{< example >}}
<button type="button" class="btn btn-primary btn-lg btn-block">Block level button</button>
<button type="button" class="btn btn-secondary btn-lg btn-block">Block level button</button>
{{< /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 <code>aria-pressed="true"</code> attribute) should you need to replicate the state programmatically.
{{< example >}}
<a href="#" class="btn btn-primary btn-lg active" role="button" aria-pressed="true">Primary link</a>
<a href="#" class="btn btn-secondary btn-lg active" role="button" aria-pressed="true">Link</a>
{{< /example >}}
## Disabled state
Make buttons look inactive by adding the `disabled` boolean attribute to any `<button>` element.
{{< example >}}
<button type="button" class="btn btn-lg btn-primary" disabled>Primary button</button>
<button type="button" class="btn btn-secondary btn-lg" disabled>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. 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.
{{< example >}}
<a href="#" class="btn btn-primary btn-lg disabled" tabindex="-1" role="button" aria-disabled="true">Primary link</a>
<a href="#" class="btn btn-secondary btn-lg disabled" tabindex="-1" role="button" aria-disabled="true">Link</a>
{{< /example >}}
{{< callout warning >}}
##### Link functionality caveat
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.
{{< /callout >}}
## 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>`.
{{< example >}}
<button type="button" class="btn btn-primary" data-toggle="button" aria-pressed="false" autocomplete="off">
Single toggle
</button>
{{< /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>`.
{{< example >}}
<div class="btn-group-toggle" data-toggle="buttons">
<label class="btn btn-secondary active">
<input type="checkbox" checked autocomplete="off"> Checked
</label>
</div>
{{< /example >}}
{{< example >}}
<div class="btn-group btn-group-toggle" data-toggle="buttons">
<label class="btn btn-secondary active">
<input type="radio" name="options" id="option1" autocomplete="off" checked> Active
</label>
<label class="btn btn-secondary">
<input type="radio" name="options" id="option2" autocomplete="off"> Radio
</label>
<label class="btn btn-secondary">
<input type="radio" name="options" id="option3" autocomplete="off"> Radio
</label>
</div>
{{< /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 >}}
<table class="table">
<thead>
<tr>
<th>Method</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code>toggle</code>
</td>
<td>
Toggles push state. Gives the button the appearance that it has been activated.
</td>
</tr>
<tr>
<td>
<code>dispose</code>
</td>
<td>
Destroys an element's button.
</td>
</tr>
</tbody>
</table>
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 >}}