Advance Select
Phoenix uses Choices.js for advance select. Choices.js is a lightweight, configurable select box/text input plugin. Similar to Select2 and Selectize but without the jQuery dependency
Documentation for Choices<label for="organizerMultiple">Multiple</label><select class="form-select" id="organizerMultiple" data-choices="data-choices" multiple="multiple" data-options='{"removeItemButton":true,"placeholder":true}'>
<option value="">Select organizer...</option>
<option>Massachusetts Institute of Technology</option>
<option>University of Chicago</option>
<option>GSAS Open Labs At Harvard</option>
<option>California Institute of Technology</option>
</select>California Institute of Technology
GSAS Open Labs At Harvard
Massachusetts Institute of Technology
University of Chicago
<label for="organizerSingle">Single</label><select class="form-select" id="organizerSingle" data-choices="data-choices" data-options='{"removeItemButton":true,"placeholder":true}'>
<option value="">Select organizer...</option>
<option>Massachusetts Institute of Technology</option>
<option>University of Chicago</option>
<option>GSAS Open Labs At Harvard</option>
<option>California Institute of Technology</option>
</select>Select organizer...
Select organizer...
California Institute of Technology
GSAS Open Labs At Harvard
Massachusetts Institute of Technology
University of Chicago
<form class="needs-validation" novalidate="novalidate">
<div class="mb-3"><label for="organizerMultiple2">Multiple</label><select class="form-select" id="organizerMultiple2" data-choices="data-choices" multiple="multiple" size="1" name="organizerMultiple" required="required" data-options='{"removeItemButton":true,"placeholder":true}'>
<option value="">Select organizer...</option>
<option>Massachusetts Institute of Technology</option>
<option>University of Chicago</option>
<option>GSAS Open Labs At Harvard</option>
<option>California Institute of Technology</option>
</select>
<div class="invalid-feedback">Please select one or multiple</div>
</div>
<div class="mb-3"><label for="organizerSingle2">Single</label><select class="form-select" id="organizerSingle2" data-choices="data-choices" size="1" required="required" name="organizerSingle" data-options='{"removeItemButton":true,"placeholder":true}'>
<option value="">Select organizer...</option>
<option>Massachusetts Institute of Technology</option>
<option>University of Chicago</option>
<option>GSAS Open Labs At Harvard</option>
<option>California Institute of Technology </option>
</select>
<div class="invalid-feedback">Please select one</div>
</div><button class="btn btn-primary" type="submit">Submit form</button>
</form><pre><code class="language-html"><link href="vendors/choices/choices.min.css" rel="stylesheet" /></code></pre><link href="vendors/choices/choices.min.css" rel="stylesheet" />