Populating a dropdown with a django variable after AJAX call

Question

I have a dropdown that triggers an AJAX call when a new value is selected. The AJAX script calls my Django view, which returns a variable (a list of values). It seems to work until the step where I need to fill a second dropdown with the values from that list. I couldn't figure out how to do this.

Here is my html code:

<form class="wrapper" action="" method="post"> {% csrf_token %} 

  <select name="myVal" class="toChange">
    <option val="1">1</option>  
    <option val="2">2</option>   
  </select>

  <select id="dep" name="dep">  </select>


  <script type="text/javascript">
    function dropdownChange () {
      var selectedValue = $(".toChange option:selected").val();
      $.ajax({
              url: '/myApp/templates/3/',
              type: 'POST',
              data: {'myVal': selectedValue},
              success: function(result) {
                alert(result);
              }
              }); 
    }
    $(".toChange").change(dropdownChange);

  </script>

</form>

And here is my views.py file:

@csrf_exempt
def MyView3(request):

    if request.method == 'POST' and request.is_ajax:

        myVariable = json.dumps(["1", "2", "3", "4", "a"]) 


        return HttpResponse(myVariable , content_type='application/json')
    else:
        return render(request,'home3.html')

When I select a new value in my dropdown, it triggers the AJAX call and the alert(result) line returns "1,2,3,4,a". So this part works, but I don't know how to populate with these values my "dep" dropdown.

I've been trying to insert the following code in the script, but it didn't produce any results:

    var select = document.getElementById("dep");
    var options = result
    for(var i = 0; i < options.length; i++) {
    var opt = options[i];
    var el = document.createElement("option");
    el.textContent = opt;
    el.value = opt;
    select.appendChild(el);

I'm not sure if this code was simply misplaced, or if it's just not the right one to use. Does anyone know what I should be doing here? Thanks

Answer 1

You can do it much simpler in success attribute of ajax request:

        success: function(data) {
            var str = '';
            data.forEach(function(opt){
                str += '<option value="' + opt + '">' + opt + '</option>';
            });
            document.getElementById("dep").innerHTML = str;
        }