Bootstrap/forms.md at 76295676a1c073f6d2cd15f5c54b0edcbbbc14c6

mirror of https://github.com/twbs/bootstrap.git synced 2024-12-12 00:08:59 +01:00

* Add support for size attribute on custom selects

* Add large custom select, document it and the small variant

* fix custom select focus state

* fix custom file input focus styles

* remove empty line

2017-11-24 14:29:59 -08:00

44 KiB

Raw Blame History

layout	title	description	group	toc
docs	Forms	Examples and usage guidelines for form control styles, layout options, and custom components for creating a wide variety of forms.	components	true

Overview

Bootstrap's form controls expand on [our Rebooted form styles]({{ site.baseurl }}/docs/{{ site.docs_version }}/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 html %}

Email address We'll never share your email with anyone else.

Password

Check me out

Submit {% endexample %}

Form controls

Textual form controls—like <input>s, <select>s, and <textarea>s—are styled with the .form-control class. Included are styles for general appearance, focus state, sizing, and more.

Be sure to explore our custom forms to further style <select>s.

{% example html %}

Email address

Example select 1 2 3 4 5

Example multiple select 1 2 3 4 5

Example textarea

{% endexample %}

For file inputs, swap the .form-control for .form-control-file.

{% example html %}

Example file input

{% endexample %}

Sizing

Set heights using classes like .form-control-lg and .form-control-sm.

{% example html %} {% endexample %}

{% example html %} Large select Default select Small select {% endexample %}

Readonly

Add the readonly boolean attribute on an input to prevent modification of the input's value. Read-only inputs appear lighter (just like disabled inputs), but retain the standard cursor.

{% example html %} {% endexample %}

Readonly plain text

If you want to have <input readonly> elements in your form styled as plain text, use the .form-control-plaintext class to remove the default form field styling and preserve the correct margin and padding.

{% example html %}

Password

{% endexample %}

{% example html %}

Password

Confirm identity {% endexample %}

Checkboxes and radios

Default checkboxes and radios are improved upon with the help of .form-check, a single class for both input types that improves the layout and behavior of their HTML elements. Checkboxes are for selecting one or several options in a list, while radios are for selecting one option from many.

Disabled checkboxes and radios are supported, but to provide a not-allowed cursor on hover of the parent <label>, you'll need to add the .disabled class to the parent .form-check. The disabled class will also lighten the text color to help indicate the input's state.

Default (stacked)

By default, any number of checkboxes and radios that are immediate sibling will be vertically stacked and appropriately spaced with .form-check.

{% example html %}

Option one is this and that—be sure to include why it's great

Option two is disabled

{% endexample %}

{% example html %}

Option one is this and that—be sure to include why it's great

Option two can be something else and selecting it will deselect option one

Option three is disabled

{% endexample %}

Inline

Group checkboxes or radios on the same horizontal row by adding .form-check-inline to any .form-check.

{% example html %}

{% endexample %}

{% example html %}

{% endexample %}

Without labels

Add .position-static to inputs within .form-check that don't have any label text. Remember to still provide some form of label for assistive technologies (for instance, using aria-label).

{% example html %}

{% endexample %}

Layout

Since Bootstrap applies display: block and width: 100% to almost all our form controls, forms will by default stack vertically. Additional classes can be used to vary this layout on a per-form basis.

Form groups

The .form-group class is the easiest way to add some structure to forms. Its only purpose is to provide margin-bottom around a label and control pairing. As a bonus, since it's a class you can use it with <fieldset>s, <div>s, or nearly any other element.

{% example html %}

Example label

Another label

{% endexample %}

Form grid

More complex forms can be built using our grid classes. Use these for form layouts that require multiple columns, varied widths, and additional alignment options.

{% example html %}

{% endexample %}

Form row

You may also swap .row for .form-row, a variation of our standard grid row that overrides the default column gutters for tighter and more compact layouts.

{% example html %}

{% endexample %}

More complex layouts can also be created with the grid system.

{% example html %}

Password

Address

Address 2

City

State Choose... ...

Zip

Check me out

Horizontal form

Create horizontal forms with the grid by adding the .row class to form groups and using the .col-*-* classes to specify the width of your labels and controls.

Be sure to add .col-form-label to your <label>s as well so they're vertically centered with their associated form controls. For <legend> elements, you can use .col-form-legend to make them appear similar to regular <label> elements.

{% example html %}

Password

Radios

Option one is this and that—be sure to include why it's great

Option two can be something else and selecting it will deselect option one

Option three is disabled

Checkbox

Check me out

{% endexample %}

Horizontal form label sizing

Be sure to use .col-form-label-sm or .col-form-label-lg to your <label>s to correctly follow the size of .form-control-lg and .form-control-sm.

{% example html %}

{% endexample %}

Column sizing

As shown in the previous examples, our grid system allows you to place any number of .cols within a .row or .form-row. They'll split the available width equally between them. You may also pick a subset of your columns to take up more or less space, while the remaining .cols equally split the rest, with specific column classes like .col-7.

{% example html %}

{% endexample html %}

Auto-sizing

The example below uses a flexbox utility to vertically center the contents and changes .col to .col-auto so that your columns only take up as much space as needed. Put another way, the column sizes itself based on the contents.

{% example html %}

Name

Username

Remember me

Submit

{% endexample %}

You can then remix that once again with size-specific column classes.

{% example html %}

Name

Username

Remember me

Submit

{% endexample %}

And of course custom form controls are supported.

{% example html %}

Preference Choose... One Two Three

Remember my preference

Submit

{% endexample %}

Inline forms

Use the .form-inline class to display a series of labels, form controls, and buttons on a single horizontal row. Form controls within inline forms vary slightly from their default states.

Controls are display: flex, collapsing any HTML white space and allowing you to provide alignment control with [spacing]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/spacing/) and [flexbox]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/flex/) utilities.
Controls and input groups receive width: auto to override the Bootstrap default width: 100%.
Controls only appear inline in viewports that are at least 576px wide to account for narrow viewports on mobile devices.

You may need to manually address the width and alignment of individual form controls with [spacing utilities]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/spacing/) (as shown below). Lastly, be sure to always include a <label> with each form control, even if you need to hide it from non-screenreader visitors with .sr-only.

{% example html %}

Name

Username

Remember me

Submit

{% endexample %}

Custom form controls and selects are also supported.

{% example html %}

Preference Choose... One Two Three Remember my preference

Submit

{% endexample %}

{% callout warning %}

Alternatives to hidden labels

Assistive technologies such as screen readers will have trouble with your forms if you don't include a label for every input. For these inline forms, you can hide the labels using the .sr-only class. There are further alternative methods of providing a label for assistive technologies, such as the aria-label, aria-labelledby or title attribute. If none of these are present, assistive technologies may resort to using the placeholder attribute, if present, but note that use of placeholder as a replacement for other labelling methods is not advised. {% endcallout %}

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. {% endcallout %}

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 html %} Password Your password must be 8-20 characters long, contain letters and numbers, and must not contain spaces, special characters, or emoji. {% endexample %}

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 html %}

Password Must be 8-20 characters long.

{% endexample %}

Disabled forms

Add the disabled boolean attribute on an input to prevent user interactions and make it appear lighter.

{% highlight html %} {% endhighlight %}

Add the disabled attribute to a <fieldset> to disable all the controls within.

{% example html %}

Disabled input

Disabled select menu Disabled select

Can't check this

Submit {% endexample %}

{% callout warning %}

Caveat with anchors

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. As noted in the section about [disabled state for buttons]({{ site.baseurl }}/docs/{{ site.docs_version }}/components/buttons/#disabled-state) (and specifically in the sub-section for anchor elements), this CSS property is not yet standardized and isn't fully supported in Opera 18 and below, or in Internet Explorer 10, and won't prevent keyboard users from being able to focus or activate these links. So to be safe, use custom JavaScript to disable such links. {% endcallout %}

{% callout danger %}

Cross-browser compatibility

While Bootstrap will apply these styles in all browsers, Internet Explorer 11 and below don't fully support the disabled attribute on a <fieldset>. Use custom JavaScript to disable the fieldset in these browsers. {% endcallout %}

Validation

Provide valuable, actionable feedback to your users with HTML5 form validation–available in all our supported browsers. Choose from the browser default validation feedback, or implement custom messages with our built-in classes and starter JavaScript.

{% callout warning %} We highly recommend custom validation styles as native browser defaults are not announced to screen readers. {% endcallout %}

How it works

Here's how form validation works with Bootstrap:

HTML form validation is applied via CSS's two pseudo-classes, :invalid and :valid. It applies to <input>, <select>, and <textarea> elements.
Bootstrap scopes the :invalid and :valid styles to parent .was-validated class, usually applied to the <form>. Otherwise, any required field without a value shows up as invalid on page load. This way, you may choose when to activate them (typically after form submission is attempted).
As a fallback, .is-invalid and .is-valid classes may be used instead of the pseudo-classes for server side validation. They do not require a .was-validated parent class.
Due to constraints in how CSS works, we cannot (at present) apply styles to a <label> that comes before a form control in the DOM without the help of custom JavaScript.
All modern browsers support the constraint validation API, a series of JavaScript methods for validating form controls.
Feedback messages may utilize the browser defaults (different for each browser, and unstylable via CSS) or our custom feedback styles with additional HTML and CSS.
You may provide custom validity messages with setCustomValidity in JavaScript.

With that in mind, consider the following demos for our custom form validation styles, optional server side classes, and browser defaults.

Custom styles

For custom Bootstrap form validation messages, you'll need to add the novalidate boolean attribute to your <form>. This disables the browser default feedback tooltips, but still provides access to the form validation APIs in JavaScript. Try to submit the form below; our JavaScript will intercept the submit button and relay feedback to you.

When attempting to submit, you'll see the :invalid and :valid styles applied to your form controls.

{% example html %}

First name

Last name

City

Please provide a valid city.

State

Please provide a valid state.

Zip

Please provide a valid zip.

Submit form

{% endexample %}

Browser defaults

Not interested in custom validation feedback messages or writing JavaScript to change form behaviors? All good, you can use the browser defaults. Try submitting the form below. Depending on your browser and OS, you'll see a slightly different style of feedback.

While these feedback styles cannot be styled with CSS, you can still customize the feedback text through JavaScript.

{% example html %}

First name

Last name

City

Please provide a valid city.

State

Please provide a valid state.

Zip

Please provide a valid zip.

Submit form

{% endexample %}

Server side

We recommend using client side validation, but in case you require server side, you can indicate invalid and valid form fields with .is-invalid and .is-valid. Note that .invalid-feedback is also supported with these classes.

{% example html %}

First name

Last name

City

Please provide a valid city.

State

Please provide a valid state.

Zip

Please provide a valid zip.

Submit form

{% endexample %}

Supported elements

Our example forms show native textual <input>s above, but form validation styles are available for our custom form controls, too.

{% example html %}

Check this custom checkbox

Toggle this custom radio Or toggle this other custom radio

Open this select menu One Two Three {% endexample %}

Custom forms

For even more customization and cross browser consistency, use our completely custom form elements to replace the browser defaults. They're built on top of semantic and accessible markup, so they're solid replacements for any default form control.

Checkboxes and radios

Each checkbox and radio is wrapped in a <label> for three reasons:

It provides a larger hit areas for checking the control.
It provides a helpful and semantic wrapper to help us replace the default <input>s.
It triggers the state of the <input> automatically, meaning no JavaScript is required.

We hide the default <input> with opacity and use the .custom-control-indicator to build a new custom form indicator in its place. Unfortunately we can't build a custom one from just the <input> because CSS's content doesn't work on that element.

We use the sibling selector (~) for all our <input> states—like :checked—to properly style our custom form indicator. When combined with the .custom-control-description class, we can also style the text for each item based on the <input>'s state.

In the checked states, we use base64 embedded SVG icons from Open Iconic. This provides us the best control for styling and positioning across browsers and devices.

Checkboxes

{% example html %} Check this custom checkbox {% endexample %}

Custom checkboxes can also utilize the :indeterminate pseudo class when manually set via JavaScript (there is no available HTML attribute for specifying it).

Check this custom checkbox

If you're using jQuery, something like this should suffice:

{% highlight js %} $('.your-checkbox').prop('indeterminate', true) {% endhighlight %}

Radios

{% example html %} Toggle this custom radio Or toggle this other custom radio {% endexample %}

Disabled

Custom checkboxes and radios can also be disabled. Add the disabled boolean attribute to the <input> and the custom indicator and label description will be automatically styled.

{% example html %} Check this custom checkbox

Toggle this custom radio {% endexample %}

Stacked

Custom checkboxes and radios are inline to start. Add a parent with class .custom-controls-stacked to ensure each form control is on separate lines.

{% example html %}

Toggle this custom radio Or toggle this other custom radio

{% endexample %}

Custom <select> menus need only a custom class, .custom-select to trigger the custom styles.

{% example html %} Open this select menu One Two Three {% endexample %}

You may also choose from small and large custom selects to match our similarly sized text inputs.

{% example html %} Open this select menu One Two Three Open this select menu One Two Three {% endexample %}

The multiple attribute is also supported:

{% example html %} Open this select menu One Two Three {% endexample %}

As is the size attribute:

{% example html %} Open this select menu One Two Three {% endexample %}

File browser

The file input is the most gnarly of the bunch and require additional JavaScript if you'd like to hook them up with functional Choose file... and selected file name text.

{% example html %} {% endexample %}

Here's how it works:

We wrap the <input> in a <label> so the custom control properly triggers the file browser.
We hide the default file <input> via opacity.
We use ::after to generate a custom background and directive (Choose file...).
We use ::before to generate and position the Browse button.
We declare a height on the <input> for proper spacing for surrounding content.

In other words, it's an entirely custom element, all generated via CSS.

Translating or customizing the strings

The :lang() pseudo-class is used to allow for easy translation of the "Browse" and "Choose file..." text into other languages. Simply override or add entries to the $custom-file-text SCSS variable with the relevant language tag and localized strings. The English strings can be customized the same way. For example, here's how one might add a Spanish translation (Spanish's language code is es):

{% highlight scss %} $custom-file-text: ( placeholder: ( en: "Choose file...", es: "Seleccionar archivo..." ), button-label: ( en: "Browse", es: "Navegar" ) ); {% endhighlight %}

You'll need to set the language of your document (or subtree thereof) correctly in order for the correct text to be shown. This can be done using the lang attribute or the Content-Language HTTP header, among other methods.

44 KiB Raw Blame History Unescape Escape

Overview

Form controls

Sizing

Readonly

Readonly plain text

Checkboxes and radios

Default (stacked)

Inline

Without labels

Layout

Form groups

Form grid

Form row

Horizontal form

Horizontal form label sizing

Column sizing

Auto-sizing

Inline forms

Alternatives to hidden labels

Help text

Associating help text with form controls

Disabled forms

Caveat with anchors

Cross-browser compatibility

Validation

How it works

Custom styles

Browser defaults

Server side

Supported elements

Custom forms

Checkboxes and radios

Checkboxes

Radios

Disabled

Stacked

Select menu

File browser

Translating or customizing the strings

44 KiB

Raw Blame History