Dropdown dynamic in django ajax - django

Question

I am using django for dynamic dropdown. There are two dropdown when the first dropdown was click and there is a subcategory for it, the second dropdown will show options. I want to disable the second dropdown if there is no subcategory for it. How can I do that?
$("#id_general-collision_type").change(function () {
const url = $("#form_incidentgeneral").attr("data-acc-url"); // get the url of the `load_cities` view
const collisionId = $(this).val(); // get the selected country ID from the HTML input
$.ajax({ // initialize an AJAX request
url: url, // set the url of the request (= /persons/ajax/load-cities/ )
data: {
'collision_type_id': collisionId // add the country id to the GET parameters
},
success: function (data) {
//console.log(data) // `data` is the return of the `load_cities` view function
$("#id_general-collision_subcategory").html(data); // replace the contents of the city input with the data that came from the server
let html_data = '<option value="">---------</option>';
data.forEach(function (collision_subcategory) {
html_data += `<option value="${collision_subcategory.id}">${collision_subcategory.sub_category}</option>`
});
console.log(html_data);
$("#id_general-collision_subcategory").html(html_data);
}
});
});

Answer 1

success: function (data) {
let select_element = $('select'); #Sub_category select
$(select_element).html(''); #Make Empty Select
for(let i=;i<data.length;i++){
let x = data[i];
let option_element = `<option value='${x['id']}'`>${x['sub_category']}</option>`;
$(select_element).append(option_element);
}
}