javascript - How to dynamically modify <select> in materialize css framework

Question

I just started using the materialize css framework. Now, materialize converts any select tag into a collection of ul and li elements. Before, using JQuery, I was able to do this:

var $selectDropdown = $("#dropdownid");
$selectDropdown.empty();
$selectDropdown.html(' ');
var value = "some value";
$selectDropdown .append($("<option></option>").attr("value",value).text(value));

My html is just a sample select tag:

Before, this was working. Now it fails. What would be an alternative for repopulating this dropdown dynamically using javascript?

Answer 1

According to the Docs on Materialize Forms:

In addition, you will need a separate call for any dynamically generated select elements your page generates

So the best way is to just re-bind the generated select with an additional call to .material_select().

For re-usability, you can set up a listener when the elements have changed and then trigger that listener whenever you update the original select

// 1) setup listener for custom event to re-initialize on change
$('select').on('contentChanged', function() {
  $(this).material_select();
});

// 2a) Whenever you do this --> add new option
$selectDropdown.append($("<option></option>"));

// 2b) Manually do this --> trigger custom event
$selectDropdown.trigger('contentChanged');

This has the benefit of only needing to update the particular select element that has changed.

Demo in jsFiddle & Stack Snippets:

$(function() {

  // initialize
  $('.materialSelect').material_select();

  // setup listener for custom event to re-initialize on change
  $('.materialSelect').on('contentChanged', function() {
    $(this).material_select();
  });

  // update function for demo purposes
  $("#myButton").click(function() {
    
     // add new value
    var newValue = getNewDoggo();
    var $newOpt = $("<option>").attr("value",newValue).text(newValue)
    $("#myDropdown").append($newOpt);

    // fire custom event anytime you've updated select
    $("#myDropdown").trigger('contentChanged');
    
  });

});

function getNewDoggo() {
  var adjs =  ['Floofy','Big','Cute','Cuddly','Lazy'];
  var nouns = ['Doggo','Floofer','Pupper','Fluffer', 'Nugget'];
  var newOptValue = adjs[Math.floor(Math.random() * adjs.length)] + " " + 
                    nouns[Math.floor(Math.random() * nouns.length)];
  return newOptValue;
}

body { padding: 25px}

<link  href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/css/materialize.min.css" rel="stylesheet">
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.96.1/js/materialize.min.js"></script>

<button class="waves-effect waves-light btn" id="myButton">
  Add New Option to Dropdown
</button>

<select id="myDropdown" class="materialSelect">
  <option value="Happy Floof">Happy Floof</option>
  <option value="Derpy Biscuit">Derpy Biscuit</option>
</select>