Spinners ^commun

Un spinner est un élément graphique qui indique l'état de chargement d'une page ou d'un élément de page.
Aucun JS n'est nécessaire.
Possibilité pré-établie de skinner la couleur, la taille, le style graphique et l'animation.
Pour des raisons d'accessibilité, un span avec la classe .visually-hidden et un contenu explicatif doivent être en place dans le spinner, qui doit lui-même porter l'attribut role="status".

<div class="spinner-border" role="status">
    <span class="visually-hidden">Loading...</span>
</div>

Nous utilisons ici les classes utilitaires de couleur de texte pour skinner les spinners.
Par défaut, les spinners prennent la currentColor ce qui explique l'usage des classes .text-* plutôt que des classes de bordure.

<div class="spinner-border text-primary" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-secondary" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-success" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-danger" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-warning" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-info" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-light" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-border text-dark" role="status">
    <span class="visually-hidden">Loading...</span>
</div>

Voici un autre style disponible avec un autre effet (et toutes ses déclinaisons).

<div class="spinner-grow text-primary" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-secondary" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-success" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-danger" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-warning" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-info" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-light" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow text-dark" role="status">
    <span class="visually-hidden">Loading...</span>
</div>

Possibilité d'ajouter une classe utilitaire de marge pour caler l'élément facilement.

<div class="spinner-border m-5" role="status">
    <span class="visually-hidden">Loading...</span>
</div>

Possibilité d'utiliser les utilitaires de mécanisme flex et de floating pour gérer la position de l'élément.

<div class="d-flex justify-content-center">
    <div class="spinner-border" role="status">
        <span class="visually-hidden">Loading...</span>
    </div>
</div>

<div class="d-flex align-items-center">
    <strong>Loading...</strong>
    <div class="spinner-border ms-auto" role="status" aria-hidden="true"></div>
</div>

<div class="clearfix">
    <div class="spinner-border float-end" role="status">
        <span class="visually-hidden">Loading...</span>
    </div>
</div>

<div class="text-center">
    <div class="spinner-border" role="status">
        <span class="visually-hidden">Loading...</span>
    </div>
</div>

Ajouter .spinner-border-sm ou .spinner-sm pour obtenir un spinner plus petit.
Pour obtenir un résultat plus grand, ne pas hésiter à enrichir les styles via le width et le height en CSS.

<div class="spinner-border spinner-border-sm" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow spinner-grow-sm" role="status">
    <span class="visually-hidden">Loading...</span>
</div>

<div class="spinner-border" style="width: 5rem; height: 5rem;" role="status">
    <span class="visually-hidden">Loading...</span>
</div>
<div class="spinner-grow" style="width: 5rem; height: 5rem;" role="status">
    <span class="visually-hidden">Loading...</span>
</div>

<button class="btn btn-primary" type="button" disabled>
    <span class="spinner-border spinner-border-sm" aria-hidden="true"></span>
    <span class="visually-hidden" role="status">Loading...</span>
</button>
<button class="btn btn-primary" type="button" disabled>
    <span class="spinner-border spinner-border-sm" aria-hidden="true"></span>
    <span role="status">Loading...</span>
</button>

/* border */
--#{$prefix}spinner-width: #{$spinner-width};
--#{$prefix}spinner-height: #{$spinner-height};
--#{$prefix}spinner-vertical-align: #{$spinner-vertical-align};
--#{$prefix}spinner-border-width: #{$spinner-border-width};
--#{$prefix}spinner-animation-speed: #{$spinner-animation-speed};
--#{$prefix}spinner-animation-name: spinner-border;

/* grow */
--#{$prefix}spinner-width: #{$spinner-width};
--#{$prefix}spinner-height: #{$spinner-height};
--#{$prefix}spinner-vertical-align: #{$spinner-vertical-align};
--#{$prefix}spinner-animation-speed: #{$spinner-animation-speed};
--#{$prefix}spinner-animation-name: spinner-grow;

$spinner-width:           2rem;
$spinner-height:          $spinner-width;
$spinner-vertical-align:  -.125em;
$spinner-border-width:    .25em;
$spinner-animation-speed: .75s;

$spinner-width-sm:        1rem;
$spinner-height-sm:       $spinner-width-sm;
$spinner-border-width-sm: .2em;