bootstrap 3 loading icon code example
Example: 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>