you can try with DOMNodeInserted and look for select or the class you’re assigning them
$('body').on('DOMNodeInserted', 'select', function () {
$(this).select2();
});
Update
DOMNodeInserted
Deprecated
This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible;
The suggested method would be something like this with MutationObserver
$(function() {
$("button").on("click", function() {
$("#dynamic-container").append($("<select><option>test</option><select/>"));
});
// select the target node
var target = document.getElementById('dynamic-container');
if (target) {
// create an observer instance
var observer = new MutationObserver(function(mutations) {
//loop through the detected mutations(added controls)
mutations.forEach(function(mutation) {
//addedNodes contains all detected new controls
if (mutation && mutation.addedNodes) {
mutation.addedNodes.forEach(function(elm) {
//only apply select2 to select elements
if (elm && elm.nodeName === "SELECT") {
$(elm).select2();
}
});
}
});
});
// pass in the target node, as well as the observer options
observer.observe(target, {
childList: true
});
// later, you can stop observing
//observer.disconnect();
}
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script><link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/css/select2.min.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/js/select2.min.js"></script>
<button>Add new select</button>
<div id="dynamic-container">
</div>