Question

I have two dropdownlistfor, and the second of them should be filled with an array based on the value of the first dropdownlist

I’ve tried to follow Darins Answer here but I have problem getting the second dropdownlistforto work and filled with my array. My second Dropdownlisfor is not getting filled, instead, it disappear.

This my script for using JSON

    <script type="text/javascript">
    $(function () {
        $('#teamname').change(function () {
            var selectednametext = $(this).find("option:selected").text();
            $.getJSON('@Url.Action("TeamName")', { TeamName: selectednametext }, function (persons) {
                var selectedpersons = $('#personname');
                selectedpersons.empty();
                $.each(persons, function (index, person) {
                    selectedpersons.append(
                    $('<option/>')
                        .attr('value', person.name)
                        .text(person.name)
                );
            });
        });
    });
});
</script>

This is my DropdownListforin my view:

<p>Team</p>
        <div class="editor-field" id="teamname">
            @Html.DropDownListFor(model => model.TeamName, Model.Teams, "Select Team", new { @class = "selectstyle" })
            @Html.ValidationMessageFor(model => model.TeamName)
        </div>
        <p>Person</p>
        <div class="editor-field" id="personname">
            @Html.DropDownListFor(model => model.PersonName, Model.Person, "Select Person", new { @class = "selectstyle", @disabled = "disabled" })
            @Html.ValidationMessageFor(model => model.PersonName)

This how my array is getting filled in my controller:

public ActionResult TeamName(string teamname)
    {
        if (teamname == "Team A")
        {
            System.Collections.ArrayList teamArray = new System.Collections.ArrayList();

            new ConsultantContext(new Uri("http://foo/persons"), ConsultantContext.Format.Json)
            .Consultant
            .Where(x => x.Team == "Team A")
            .OrderBy(x => x.DisplayName)
            .ToList()
            .ForEach(item =>
            {
            teamArray.Add(item.DisplayName);
            });

            return Json(teamArray, JsonRequestBehavior.AllowGet);   
        }// and same goes with arrays for Team B and Team C

All kind of help is appreciated, thanks in advance!

Answer 1

$('#teamname') doesn’t match the id of your dropdown. Make sure that you have assigned the same id in your markup:

@Html.DropDownListFor(
    model => model.TeamName, 
    Model.Teams, 
    "Select Team", 
    new { id = "teamname", @class = "selectstyle" }
)

Same stands true for the $('#personname'); selector. You should fix your markup so that those selectors correspond to your DOM elements.

Also why are you using ArrayList? That’s prehistoric. Use strongly typed collections:

public ActionResult TeamName(string teamname)
{
    var consultants = new ConsultantContext(
        new Uri("http://foo/persons"), 
        ConsultantContext.Format.Json
    )
    .Consultant
    .Where(x => x.Team == teamname)
    .OrderBy(x => x.DisplayName)
    .ToList()
    .Select(x => new 
    {
        name = x.DisplayName
    });

    return Json(consultants, JsonRequestBehavior.AllowGet);   
}