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Bootstrap/site/content/docs/4.3/forms/overview.md
2020-03-24 15:02:58 +02:00

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Markdown

---
layout: docs
title: Forms
description: Examples and usage guidelines for form control styles, layout options, and custom components for creating a wide variety of forms.
group: forms
toc: true
aliases: "/docs/4.3/forms/"
sections:
- title: Form control
description: Style textual inputs and textareas with support for multiple states.
- title: Select
description: Improve browser default select elements with a custom initial appearance.
- title: Checks
description: Use our custom radio buttons and checkboxes in forms for selecting input options.
- title: File
description: Replace browser default file inputs with our custom version with optional JavaScript.
- title: Range
description: Replace browser default range inputs with our custom version.
- title: Input group
description: Attach labels and buttons to your inputs for increased semantic value.
- title: Layout
description: Create inline, horizontal, or complex grid-based layouts with your forms.
- title: Validation
description: Validate your forms with custom or native validation behaviors and styles.
---
## Overview
Bootstrap's form controls expand on [our Rebooted form styles]({{< docsref "/content/reboot#forms" >}}) with classes. Use these classes to opt into their customized displays for a more consistent rendering across browsers and devices.
Be sure to use an appropriate `type` attribute on all inputs (e.g., `email` for email address or `number` for numerical information) to take advantage of newer input controls like email verification, number selection, and more.
Here's a quick example to demonstrate Bootstrap's form styles. Keep reading for documentation on required classes, form layout, and more.
{{< example >}}
<form>
<div class="mb-3">
<label for="exampleInputEmail1">Email address</label>
<input type="email" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp">
<small id="emailHelp" class="form-text text-muted">We'll never share your email with anyone else.</small>
</div>
<div class="mb-3">
<label for="exampleInputPassword1">Password</label>
<input type="password" class="form-control" id="exampleInputPassword1">
</div>
<div class="mb-3 form-check">
<input type="checkbox" class="form-check-input" id="exampleCheck1">
<label class="form-check-label" for="exampleCheck1">Check me out</label>
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</form>
{{< /example >}}
## Help text
Block-level help text in forms can be created using `.form-text` (previously known as `.help-block` in v3). Inline help text can be flexibly implemented using any inline HTML element and utility classes like `.text-muted`.
{{< callout warning >}}
##### Associating help text with form controls
Help text should be explicitly associated with the form control it relates to using the `aria-describedby` attribute. This will ensure that assistive technologies—such as screen readers—will announce this help text when the user focuses or enters the control.
{{< /callout >}}
Help text below inputs can be styled with `.form-text`. This class includes `display: block` and adds some top margin for easy spacing from the inputs above.
{{< example >}}
<label for="inputPassword5">Password</label>
<input type="password" id="inputPassword5" class="form-control" aria-describedby="passwordHelpBlock">
<small id="passwordHelpBlock" class="form-text text-muted">
Your password must be 8-20 characters long, contain letters and numbers, and must not contain spaces, special characters, or emoji.
</small>
{{< /example >}}
Inline text can use any typical inline HTML element (be it a `<small>`, `<span>`, or something else) with nothing more than a utility class.
{{< example >}}
<div class="row g-3 align-items-center">
<div class="col-auto">
<label for="inputPassword6" class="col-form-label">Password</label>
</div>
<div class="col-auto">
<input type="password" id="inputPassword6" class="form-control" aria-describedby="passwordHelpInline">
</div>
<div class="col-auto">
<small id="passwordHelpInline" class="text-muted">
Must be 8-20 characters long.
</small>
</div>
</div>
{{< /example >}}
## Disabled forms
Add the `disabled` boolean attribute on an input to prevent user interactions and make it appear lighter.
{{< highlight html >}}
<input class="form-control" id="disabledInput" type="text" placeholder="Disabled input here..." disabled>
{{< /highlight >}}
Add the `disabled` attribute to a `<fieldset>` to disable all the controls within.
By default, browsers will treat all native form controls (`<input>`, `<select>`, and `<button>` elements) inside a `<fieldset disabled>` as disabled, preventing both keyboard and mouse interactions on them. However, if your form also includes `<a ... class="btn btn-*">` elements, these will only be given a style of `pointer-events: none`.
{{< example >}}
<form>
<fieldset disabled aria-label="Disabled fieldset example">
<div class="mb-3">
<label for="disabledTextInput">Disabled input</label>
<input type="text" id="disabledTextInput" class="form-control" placeholder="Disabled input">
</div>
<div class="mb-3">
<label for="disabledSelect">Disabled select menu</label>
<select id="disabledSelect" class="form-select">
<option>Disabled select</option>
</select>
</div>
<div class="mb-3">
<div class="form-check">
<input class="form-check-input" type="checkbox" id="disabledFieldsetCheck" disabled>
<label class="form-check-label" for="disabledFieldsetCheck">
Can't check this
</label>
</div>
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</fieldset>
</form>
{{< /example >}}