bootstrap 4 loading spinner block screen code example
Example 1: bootstrap loader
<div class="spinner-border text-primary" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-secondary" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-success" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-danger" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-warning" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-info" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-light" role="status">
<span class="sr-only">Loading...</span>
</div>
<div class="spinner-border text-dark" role="status">
<span class="sr-only">Loading...</span>
</div>
Example 2: bootstrap loader
<button class="btn btn-primary" type="button" disabled>
<span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>
<span class="sr-only">Loading...</span>
</button>
<button class="btn btn-primary" type="button" disabled>
<span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>
Loading...
</button>