Form controls

Give textual form controls like <input>s and <textarea>s an upgrade with custom styles, sizing, focus states, and more.

Example

Form controls are styled with a mix of Sass and CSS variables, allowing them to adapt to color modes and support any customization method.

Form control - 图1

html

  1. <div class="mb-3">
  2.   <label for="exampleFormControlInput1" class="form-label">Email address</label>
  3.   <input type="email" class="form-control" id="exampleFormControlInput1" placeholder="name@example.com">
  4. </div>
  5. <div class="mb-3">
  6.   <label for="exampleFormControlTextarea1" class="form-label">Example textarea</label>
  7.   <textarea class="form-control" id="exampleFormControlTextarea1" rows="3"></textarea>
  8. </div>

Sizing

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

Form control - 图2

html

  1. <input class="form-control form-control-lg" type="text" placeholder=".form-control-lg" aria-label=".form-control-lg example">
  2. <input class="form-control" type="text" placeholder="Default input" aria-label="default input example">
  3. <input class="form-control form-control-sm" type="text" placeholder=".form-control-sm" aria-label=".form-control-sm example">

Form text

Block-level or inline-level form text can be created using .form-text.

Form 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 form text when the user focuses or enters the control.

Form text below inputs can be styled with .form-text. If a block-level element will be used, a top margin is added for easy spacing from the inputs above.

Form control - 图3

html

  1. <label for="inputPassword5" class="form-label">Password</label>
  2. <input type="password" id="inputPassword5" class="form-control" aria-describedby="passwordHelpBlock">
  3. <div id="passwordHelpBlock" class="form-text">
  4.   Your password must be 8-20 characters long, contain letters and numbers, and must not contain spaces, special characters, or emoji.
  5. </div>

Inline text can use any typical inline HTML element (be it a <span>, <small>, or something else) with nothing more than the .form-text class.

Form control - 图4

html

  1. <div class="row g-3 align-items-center">
  2.   <div class="col-auto">
  3.     <label for="inputPassword6" class="col-form-label">Password</label>
  4.   </div>
  5.   <div class="col-auto">
  6.     <input type="password" id="inputPassword6" class="form-control" aria-describedby="passwordHelpInline">
  7.   </div>
  8.   <div class="col-auto">
  9.     <span id="passwordHelpInline" class="form-text">
  10.       Must be 8-20 characters long.
  11.     </span>
  12.   </div>
  13. </div>

Disabled

Add the disabled boolean attribute on an input to give it a grayed out appearance, remove pointer events, and prevent focusing.

Form control - 图5

html

  1. <input class="form-control" type="text" placeholder="Disabled input" aria-label="Disabled input example" disabled>
  2. <input class="form-control" type="text" value="Disabled readonly input" aria-label="Disabled input example" disabled readonly>

Readonly

Add the readonly boolean attribute on an input to prevent modification of the input’s value. readonly inputs can still be focused and selected, while disabled inputs cannot.

Form control - 图6

html

  1. <input class="form-control" type="text" value="Readonly input here..." aria-label="readonly input example" readonly>

Readonly plain text

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

Form control - 图7

html

  1.   <div class="mb-3 row">
  2.     <label for="staticEmail" class="col-sm-2 col-form-label">Email</label>
  3.     <div class="col-sm-10">
  4.       <input type="text" readonly class="form-control-plaintext" id="staticEmail" value="email@example.com">
  5.     </div>
  6.   </div>
  7.   <div class="mb-3 row">
  8.     <label for="inputPassword" class="col-sm-2 col-form-label">Password</label>
  9.     <div class="col-sm-10">
  10.       <input type="password" class="form-control" id="inputPassword">
  11.     </div>
  12.   </div>

Form control - 图8

html

  1. <form class="row g-3">
  2.   <div class="col-auto">
  3.     <label for="staticEmail2" class="visually-hidden">Email</label>
  4.     <input type="text" readonly class="form-control-plaintext" id="staticEmail2" value="email@example.com">
  5.   </div>
  6.   <div class="col-auto">
  7.     <label for="inputPassword2" class="visually-hidden">Password</label>
  8.     <input type="password" class="form-control" id="inputPassword2" placeholder="Password">
  9.   </div>
  10.   <div class="col-auto">
  11.     <button type="submit" class="btn btn-primary mb-3">Confirm identity</button>
  12.   </div>
  13. </form>

File input

Form control - 图9

html

  1. <div class="mb-3">
  2.   <label for="formFile" class="form-label">Default file input example</label>
  3.   <input class="form-control" type="file" id="formFile">
  4. </div>
  5. <div class="mb-3">
  6.   <label for="formFileMultiple" class="form-label">Multiple files input example</label>
  7.   <input class="form-control" type="file" id="formFileMultiple" multiple>
  8. </div>
  9. <div class="mb-3">
  10.   <label for="formFileDisabled" class="form-label">Disabled file input example</label>
  11.   <input class="form-control" type="file" id="formFileDisabled" disabled>
  12. </div>
  13. <div class="mb-3">
  14.   <label for="formFileSm" class="form-label">Small file input example</label>
  15.   <input class="form-control form-control-sm" id="formFileSm" type="file">
  16. </div>
  17. <div>
  18.   <label for="formFileLg" class="form-label">Large file input example</label>
  19.   <input class="form-control form-control-lg" id="formFileLg" type="file">
  20. </div>

Color

Set the type="color" and add .form-control-color to the <input>. We use the modifier class to set fixed heights and override some inconsistencies between browsers.

Form control - 图10

html

  1. <label for="exampleColorInput" class="form-label">Color picker</label>
  2. <input type="color" class="form-control form-control-color" id="exampleColorInput" value="#563d7c" title="Choose your color">

Datalists

Datalists allow you to create a group of <option>s that can be accessed (and autocompleted) from within an <input>. These are similar to <select> elements, but come with more menu styling limitations and differences. While most browsers and operating systems include some support for <datalist> elements, their styling is inconsistent at best.

Learn more about support for datalist elements.

Form control - 图11

html

  1. <label for="exampleDataList" class="form-label">Datalist example</label>
  2. <input class="form-control" list="datalistOptions" id="exampleDataList" placeholder="Type to search...">
  3. <datalist id="datalistOptions">
  4.   <option value="San Francisco">
  5.   <option value="New York">
  6.   <option value="Seattle">
  7.   <option value="Los Angeles">
  8.   <option value="Chicago">
  9. </datalist>

CSS

Sass variables

$input-* are shared across most of our form controls (and not buttons).

scss/_variables.scss

  1. $input-padding-y:                       $input-btn-padding-y;
  2. $input-padding-x:                       $input-btn-padding-x;
  3. $input-font-family:                     $input-btn-font-family;
  4. $input-font-size:                       $input-btn-font-size;
  5. $input-font-weight:                     $font-weight-base;
  6. $input-line-height:                     $input-btn-line-height;
  8. $input-padding-y-sm:                    $input-btn-padding-y-sm;
  9. $input-padding-x-sm:                    $input-btn-padding-x-sm;
  10. $input-font-size-sm:                    $input-btn-font-size-sm;
  12. $input-padding-y-lg:                    $input-btn-padding-y-lg;
  13. $input-padding-x-lg:                    $input-btn-padding-x-lg;
  14. $input-font-size-lg:                    $input-btn-font-size-lg;
  16. $input-bg:                              var(--#{$prefix}body-bg);
  17. $input-disabled-color:                  null;
  18. $input-disabled-bg:                     var(--#{$prefix}secondary-bg);
  19. $input-disabled-border-color:           null;
  21. $input-color:                           var(--#{$prefix}body-color);
  22. $input-border-color:                    var(--#{$prefix}border-color);
  23. $input-border-width:                    $input-btn-border-width;
  24. $input-box-shadow:                      var(--#{$prefix}box-shadow-inset);
  26. $input-border-radius:                   var(--#{$prefix}border-radius);
  27. $input-border-radius-sm:                var(--#{$prefix}border-radius-sm);
  28. $input-border-radius-lg:                var(--#{$prefix}border-radius-lg);
  30. $input-focus-bg:                        $input-bg;
  31. $input-focus-border-color:              tint-color($component-active-bg, 50%);
  32. $input-focus-color:                     $input-color;
  33. $input-focus-width:                     $input-btn-focus-width;
  34. $input-focus-box-shadow:                $input-btn-focus-box-shadow;
  36. $input-placeholder-color:               var(--#{$prefix}secondary-color);
  37. $input-plaintext-color:                 var(--#{$prefix}body-color);
  39. $input-height-border:                   calc(#{$input-border-width} * 2); // stylelint-disable-line function-disallowed-list
  41. $input-height-inner:                    add($input-line-height * 1em, $input-padding-y * 2);
  42. $input-height-inner-half:               add($input-line-height * .5em, $input-padding-y);
  43. $input-height-inner-quarter:            add($input-line-height * .25em, $input-padding-y * .5);
  45. $input-height:                          add($input-line-height * 1em, add($input-padding-y * 2, $input-height-border, false));
  46. $input-height-sm:                       add($input-line-height * 1em, add($input-padding-y-sm * 2, $input-height-border, false));
  47. $input-height-lg:                       add($input-line-height * 1em, add($input-padding-y-lg * 2, $input-height-border, false));
  49. $input-transition:                      border-color .15s ease-in-out, box-shadow .15s ease-in-out;
  51. $form-color-width:                      3rem;

$form-label-* and $form-text-* are for our <label>s and .form-text component.

scss/_variables.scss

  1. $form-label-margin-bottom:              .5rem;
  2. $form-label-font-size:                  null;
  3. $form-label-font-style:                 null;
  4. $form-label-font-weight:                null;
  5. $form-label-color:                      null;

scss/_variables.scss

  1. $form-text-margin-top:                  .25rem;
  2. $form-text-font-size:                   $small-font-size;
  3. $form-text-font-style:                  null;
  4. $form-text-font-weight:                 null;
  5. $form-text-color:                       var(--#{$prefix}secondary-color);

$form-file-* are for file input.

scss/_variables.scss

  1. $form-file-button-color:          $input-color;
  2. $form-file-button-bg:             var(--#{$prefix}tertiary-bg);
  3. $form-file-button-hover-bg:       var(--#{$prefix}secondary-bg);