0
0
mirror of https://github.com/twbs/bootstrap.git synced 2024-12-10 22:24:19 +01:00
Bootstrap/docs/components/forms.md
2015-05-29 01:58:52 -07:00

30 KiB

layout title
page Forms

Bootstrap provides several form control styles, layout options, and custom components for creating a wide variety of forms.

Contents

  • Will be replaced with the ToC, excluding the "Contents" header {:toc}

Form controls

Bootstrap's form controls expand on our Rebooted form styles with classes. Use these classes to opt into their customized displays for a more consistent rendering across browsers and devices. The example form below demonstrates common HTML form elements that receive updated styles from Bootstrap with additional classes.

Remember, since Bootstrap utilizies the HTML5 doctype, all inputs must have a type attribute for proper rendering.

{% example html %}

1 2 3 4 5 1 2 3 4 5

This is some placeholder block-level help text for the above input. It's a bit lighter and easily wraps to a new line.

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
Check me out
Submit {% endexample %}

Below is a complete list of the specific from controls supported by Bootstrap and the classes that customize them. Additional documentation is available for each group.

Classes Used for Supported variations
{% markdown %}`.form-group`{% endmarkdown %} Any group of form controls {% markdown %}Use with any block-level element like `` or `
`{% endmarkdown %}
{% markdown %}`.form-control`{% endmarkdown %} Textual inputs {% markdown %}`text`, `password`, `datetime`, `datetime-local`, `date`, `month`, `time`, `week`, `number`, `email`, `url`, `search`, `tel`, `color`{% endmarkdown %}
Select menus {% markdown %}`multiple`, `size`{% endmarkdown %}
Textareas N/A
{% markdown %}`.form-control-file`{% endmarkdown %} File inputs {% markdown %}`file`{% endmarkdown %}
{% markdown %} `.radio`
`.radio-inline`
`.checkbox`
`.checkbox-inline` {% endmarkdown %}
Checkboxes and radios N/A

Form layouts

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. It's 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 %}

{% endexample %}

Inline forms

Use the .inline-form class to to display a series of labels, form controls, and buttons on a single horizontal row. Form controls within inline forms behave differently:

  • Controls are display: inline-block to provide alignment control via vertical-align and margin.
  • Controls receive width: auto to override the Bootstrap default width: 100%.
  • Controls only appear inline in viewports that are at least 768px wide to account for narrow viewports on mobile devices.

Because of this, you may need to manually address the width and alignment of individual form controls. Lastly, as shown below, you should always include a <label> with each form control.

Visible labels

{% example html %}

Send invitation {% endexample %}

Hidden labels

{% example html %}

Remember me
Sign in {% endexample %}

{% example html %}

$
.00
Transfer cash {% endexample %}

Using the Grid

For more structured form layouts, you can utilize Bootstrap's predefined grid classes (or mixins). Add the .row class to form groups and use the .col-* classes to specify the width of your labels and controls. To vertically center the labels with the textual inputs—nearly anything with .form-control—use the .form-control-label class.

{% example html %}

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
Sign in
{% endexample %}

Checkboxes and radios

Checkboxes are for selecting one or several options in a list, while radios are for selecting one option from many.

A checkbox or radio with the disabled attribute will be styled appropriately. To have the <label> for the checkbox or radio also display a "not-allowed" cursor when the user hovers over the label, add the .disabled class to your .radio, .radio-inline, .checkbox, .checkbox-inline, or <fieldset>.

Default (stacked)

{% example html %}

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

Use the .checkbox-inline or .radio-inline classes on a series of checkboxes or radios for controls that appear on the same line.

{% example html %} 1 2 3 {% endexample %}

{% example html %} 1 2 3 {% endexample %}

Without labels

Should you have no text within the <label>, the input is positioned as you'd expect. Currently only works on non-inline checkboxes and radios.

{% example html %}

{% endexample %}

Static controls

When you need to place plain text next to a form label within a form, use the .form-control-static class on a <p>.

{% example html %}

{% endexample %}

{% example html %}

Confirm identity {% endexample %}

Focus state

We remove the default outline styles on some form controls and apply a box-shadow in its place for :focus. Shown below is a custom input that only demonstrates the :focus state on an <input> with .form-control.

Disabled states

Add the disabled boolean attribute on an input to prevent user interactions. Disabled inputs appear lighter and add a not-allowed cursor.

{% highlight html %} {% endhighlight %}

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

{% example html %}

Disabled select
Can't check this
Submit {% endexample %}

{% callout warning %}

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 (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 11, 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 %}

Readonly inputs

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 %}

Validation

Bootstrap includes validation styles for error, warning, and success states on form controls. To use, add .has-warning, .has-error, or .has-success to the parent element. Any .control-label, .form-control, and .help-block within that element will receive the validation styles.

{% callout warning %}

Conveying validation state to assistive technologies and colorblind users

Using these validation styles to denote the state of a form control only provides a visual, color-based indication, which will not be conveyed to users of assistive technologies - such as screen readers - or to colorblind users.

Ensure that an alternative indication of state is also provided. For instance, you can include a hint about state in the form control's <label> text itself (as is the case in the following code example), include a Glyphicon (with appropriate alternative text using the .sr-only class - see the Glyphicon examples), or by providing an additional help text block. Specifically for assistive technologies, invalid form controls can also be assigned an aria-invalid="true" attribute. {% endcallout %}

{% example html %}

Checkbox with success
Checkbox with warning
Checkbox with error
{% endexample %}

You can also add optional feedback icons with the addition of .has-feedback and the right icon.

{% callout warning %}

Icons, labels, and input groups

Manual positioning of feedback icons is required for inputs without a label and for input groups with an add-on on the right. You are strongly encouraged to provide labels for all inputs for accessibility reasons. If you wish to prevent labels from being displayed, hide them with the sr-only class. If you must do without labels, adjust the top value of the feedback icon. For input groups, adjust the right value to an appropriate pixel value depending on the width of your addon. {% endcallout %}

{% example html %}

(success)
(warning)
(error)
@
(success)
{% endexample %}

{% example html %}


@
(success)
{% endexample %}

{% example html %}

{% endexample %}

{% example html %}

@
(success)
{% endexample %}

For form controls with no visible label, add the .sr-only class on the label. Bootstrap will automatically adjust the position of the icon once it's been added.

{% example html %}

{% endexample %}

Control sizing

Set heights using classes like .form-control-lg, and set widths using grid column classes like .col-lg-*.

{% example html %} {% endexample %}

{% example html %} {% endexample %}

Column sizing

Wrap inputs in grid columns, or any custom parent element, to easily enforce desired widths.

{% example html %}

{% endexample %}

Help text

Block level help text for form controls.

{% example html %}

A block of help text that breaks onto a new line and may extend beyond one line.

{% 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 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 .c-indicator to build a new custom form control. We can't build a custom one from just the <input> because CSS's content doesn't work on that element.

With the sibling selector (~), we use the :checked state to trigger a makeshift checked state on the custom control.

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.

Check this custom checkbox

Heads up! You'll need to set this state manually via JavaScript as there is no available HTML attribute for specifying it. 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 %}

Stacked

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

{% example html %}

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

Select menu

Similar to the checkboxes and radios, we wrap the <select> in a <label> as a semantic wrapper that we can generate custom styles on with CSS's generated content.

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

The <select> has quite a few styles to override and includes a few hacks to get things done. Here's what's happening:

  • The appearance is reset to none for nearly all styles to correctly apply across modern browsers (meaning not IE9).
  • The :-moz-focusring is overridden so that on focus there's no inner border in Firefox.
  • The arrow is hidden in Firefox with a media query hack. (There's a longstanding open bug for a native method of addressing this.)
  • The arrow is hidden in IE10+ with a simple selector.
  • The arrow is hidden in IE9 with a separate media query hack which generates another pseudo-element to literally mask it. Not ideal, but doable.

Heads up! This one comes with some quirks right now:

  • select[multiple] is currently currently not supported.
  • Clickability is limited in IE9.
  • Firefox's dropdown of options looks rather ugly.
  • The custom caret is unable to receive the selected state's color.

Any ideas on improving these are most welcome.

File browser

{% example html %} {% endexample %}

The file input is the most gnarly of the bunch. 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.

Heads up! The custom file input is currently unable to update the Choose file... text with the filename. Without JavaScript, this might not be possible to change, but I'm open to ideas.