jQuery: Best practice to populate drop down?

Question

The example I see posted all of the time seems like it's suboptimal, because it involves concatenating strings, which seems so not jQuery. It usually looks like this:

$.getJSON("/Admin/GetFolderList/", function(result) {
    for (var i = 0; i < result.length; i++) {
        options += '<option value="' + result[i].ImageFolderID + '">' + result[i].Name + '</option>';
    }
});

Is there a better way?

Answer 1

here is an example i did on change i get children of the first select in second select

jQuery(document).ready(function($) {
$('.your_select').change(function() {
    $.ajaxSetup({
        headers:{'X-CSRF-TOKEN': $("meta[name='csrf-token']").attr('content')}
    });

    $.ajax({
        type:'POST',
        url: 'Link',
        data:{
          'id': $(this).val()
        },
        success:function(r){
          $.each(r, function(res) {
                console.log(r[res].Nom);
                 $('.select_to_populate').append($("<option />").val(r[res].id).text(r[res].Nom));
            });
        },error:function(r) {
          alert('Error');
        }
    });
});

});enter code here

Answer 2

function generateYears() {
                    $.ajax({
                        type: "GET",
                        url: "getYears.do",
                        data: "",
                        dataType: "json",
                        contentType: "application/json",
                        success: function(msg) {
                            populateYearsToSelectBox(msg);
                        }
                    });
}

function populateYearsToSelectBox(msg) {
  var options = $("#selectYear");
$.each(msg.dataCollecton, function(val, text) {
   options.append(
        $('<option></option>').val(text).html(text)
    );
});
}

Answer 3

Sure - make options an array of strings and use .join('') rather than += every time through the loop. Slight performance bump when dealing with large numbers of options...

var options = [];
$.getJSON("/Admin/GetFolderList/", function(result) {
    for (var i = 0; i < result.length; i++) {
        options.push('<option value="',
          result[i].ImageFolderID, '">',
          result[i].Name, '</option>');
    }
    $("#theSelect").html(options.join(''));
});

Yes. I'm still working with strings the whole time. Believe it or not, that's the fastest way to build a DOM fragment... Now, if you have only a few options, it won't really matter - use the technique Dreas demonstrates if you like the style. But bear in mind, you're invoking the browser's internal HTML parser i*2 times, rather than just once, and modifying the DOM each time through the loop... with a sufficient number of options. you'll end up paying for it, especially on older browsers.

Note: As Justice points out, this will fall apart if ImageFolderID and Name are not encoded properly...