DropDownList - Issue using select() after setDataSource()

[Anna]

I am using a dropdownlist widget in an ajax form used to edit an object. When the form loads, I need to initialize the dropdown, set its datasource, and programmatically set the selected dropdown item based on two values (compound key). However,  the return statement in my ddAssignee.select(function()) does not execute, so nothing gets selected. I checked the contents of ddAssignee.dataSource.view() immediately after calling setDataSource() and it was empty, so I'm assuming this is why nothing gets selected. However, I have a separate button that is  used to select the dropdown item after the form loads ("Take It" button), which works fine. I'm just trying to figure out what is missing after setting the datasource that is causing the dataSource.view() to still be empty. 

UPDATE: I overlooked this info about select(): 

• If the widget is not bound (e.g. autoBind is set to false), the select method will not pre-fetch the data before continuing with the selection and value setting (unlike the value method), and no item will be selected.

            However, setting autoBind to true still does not solve the problem.

I have attached:

-Screenshot of the edit form

-Edit form html with ajax form

-InitAssigneeDropdown() basic dropdown initialization

-GetAllAssigneesDataSource() returns the remote data for the dropdown via kendo.data.DataSource

- onEditTask function (executes when button is clicked to open the edit form - where issue happens)

- "Take It" button event (where select(function()) works successfully)

Any help is greatly appreciated. Thanks! 

@model Models.Tasking.TaskModel

<div class="modal-content">

    @using (Ajax.BeginForm("SaveEditTask", "Tasking", null, new AjaxOptions()
    {
        UpdateTargetId = "frmEditTask",
        InsertionMode = InsertionMode.Replace,
        OnSuccess = "taskingSaveSuccess"
    }, new { id = "frmEditTask", autocomplete = "off" }))
    {
        <div class="modal-header">
            <h5 class="modal-title" id="modalTitle">Edit Task</h5>
        </div>
        <div class="modal-body" style="max-height:70vh; overflow-y:auto">
            @Html.AntiForgeryToken()

            @Html.ValidationSummary(false, "", new { @class = "text-danger" })

            @Html.HiddenFor(m => m.ID)
            @Html.HiddenFor(m => m.PtOID)
            @Html.HiddenFor(m => m.PtMRN)
            @Html.HiddenFor(m => m.CreatedByUserFK)
            @Html.HiddenFor(m => m.CreatedDTTM)

            <div class="form-group">
                @Html.LabelFor(m => m.PtFullName, new { @class = "text-dark font-weight-bold" })
                @Html.TextBoxFor(m => m.PtFullName, new { @class = "form-control mb-2", @readonly = "readonly" })
            </div>
            <div class="form-group">
                @Html.LabelFor(m => m.TypeFK, new { @class = "text-dark font-weight-bold" })
                @Html.DropDownListFor(m => m.TypeFK, (IList<SelectListItem>)ViewBag.TaskTypeOptions, new { @class = "form-control p-1 w-auto mb-2", @disabled = "disabled", @readonly = "readonly" })
            </div>
            <div class="form-group">
                @Html.LabelFor(m => m.StatusFK, new { @class = "text-dark font-weight-bold" })
                <br />
                @Html.DropDownListFor(m => m.StatusFK, (IList<SelectListItem>)ViewBag.TaskStatusOptions, new { @id = "ddTaskStatusType", @class = "form-control p-1 w-auto mb-2" })
            </div>
            <div class="form-group">
                @Html.LabelFor(m => m.PriorityFK, new { @class = "text-dark font-weight-bold" })
                <br />
                @Html.DropDownListFor(m => m.PriorityFK, (IList<SelectListItem>)ViewBag.TaskPriorityOptions, new { @id = "ddTaskPriorityType", @class = "form-control p-1 w-auto mb-2", data_default_due_date_url = Url.Action("GetDefaultDueDate", "Tasking", new { area = "" }) })
            </div>

            <div class="form-group">
                @Html.LabelFor(m => m.DueDTTM, new { @class = "text-dark font-weight-bold" })
                @if (Model.CreatedByUserFK == User.Identity.GetUserId())
                {
                    @(Html.Kendo().DateTimePickerFor(m => m.DueDTTM).HtmlAttributes(new { @id="dtpTaskDueDate", data_toggle = "tooltip", data_placement = "bottom", data_trigger = "focus", required = "required" }))
                }
                else
                {
                    @Html.TextBoxFor(m => m.DueDTTM, new { @class = "form-control mb-2", @readonly = "readonly" })
                }
            </div>

            <div class="form-group">
                @Html.LabelFor(m => m.AssigneeFK, new { @class = "text-dark font-weight-bold" })
                <br />
                <div class="row">
                    <div class="col-9 pr-0">
                        <select id="ddTaskAssignee" name="AssigneeFK" data-all-assignees-url="@Url.Action("GetAllTaskAssigneeOptions", "Tasking", new { area = "" })" />
                    </div>
                    <div class="col-3 pl-2">
                        <button id="btnSelfAssignTask" type="button" class="btn btn-secondary" data-user-id-url="@Url.Action("GetUserId", "Tasking", new { area = "" })">Take It</button>
                    </div>
                </div>
                @Html.HiddenFor(m => m.AssigneeTypeFK, new { @id = "hiddenAssigneeTypeFK" })
            </div>

            <div class="form-group">
                @Html.LabelFor(m => m.Description, new { @class = "text-dark font-weight-bold" })
                @if (Model.CreatedByUserFK == User.Identity.GetUserId())
                {
                    @Html.TextAreaFor(m => m.Description, new { @class = "form-control" })
                }
                else
                {
                    @Html.TextAreaFor(m => m.Description, new { @class = "form-control", @readonly = "readonly" })
                }
            </div>

        </div>

        <div class="modal-footer">
            @if (Model.CreatedByUserFK == User.Identity.GetUserId())
            {
                <button id="btnDeleteTask" type="button" class="btn btn-danger" data-target-url="@Url.Action("DeleteTask", "Tasking", new { area = "" })">Delete Task</button>
            }
            <button type="button" class="btn btn-secondary" data-dismiss="modal">Cancel</button>
            <button type="submit" class="btn btn-primary">Save</button>
        </div>
    }

</div>

function initAssigneeDropDown() {
    $("#ddTaskAssignee").kendoDropDownList({
        optionLabel: 'Select Assignee ...',
        filter: "contains",
        dataTextField: 'AssigneeName',
        dataValueField: 'AssigneeFK',
        template: function (dataItem) {
            //TODO - improve logic
            if (dataItem.AssigneeTypeFK == 1)
                return '<span><i class="fas fa-user pr-2"></i>' + dataItem.AssigneeName + '</span>';
            else if (dataItem.AssigneeTypeFK == 2)
                return '<span><i class="fas fa-users pr-2"></i>' + dataItem.AssigneeName + '</span>';
        }
    });
}

function getAllAssigneesDataSource() {
    var url = $('#ddTaskAssignee').data('all-assignees-url');

    var dataSource = new kendo.data.DataSource({
        transport: {
            read: {
                type: "POST",
                url: url
            }
        }
    });

    return dataSource;
}

function onEditTask(e) {
    //Fetch the ID, assigneeTypeFK, and assigneeFK from the grid item that's getting edited
    var grid = $('#taskGrid').data('kendoGrid');
    var taskDataItem = grid.dataItem($(e).closest("tr"));
    var taskId = taskDataItem.ID;
    var assigneeTypeFK = taskDataItem.AssigneeTypeFK;
    var assigneeFK = taskDataItem.AssigneeFK; 

    $('#taskModal').modal('show'); //Show the edit modal

    $('#taskModal .modal-content').html(''); //Clear out the modal container

    //ajax to return partial view for editing task
    $.ajax({
        url: $(e).data("target-url"), 
        type: "POST",
        cache: false,
        data: JSON.stringify({ taskId: taskId }), //Pass the task id to controller
        contentType: "application/json; charset=utf-8",
        success: function (response) {
            $('#taskModal .modal-content').replaceWith(response); //add edit view html to modal

            initAssigneeDropDown();
            var ddAssignee = $('#ddTaskAssignee').data('kendoDropDownList');
            ddAssignee.setDataSource(dataSource);
            var assigneeDataSourceView = ddAssignee.dataSource.view(); //Issue - this is empty so select (below) will not work

            ddAssignee.select(function (dataItem) {
                return dataItem.AssigneeTypeFK == assigneeTypeFK && dataItem.AssigneeFK == assigneeFK;
            });

        },
        error: function (jqXHR, exception) {
            if (jqXHR.statusText !== 'abort') {
                // Our error logic here
                $('#kNotification').data('kendoNotification').error("An error occurred while loading the page.");
            }
        }
    });
    
}

$('#taskModal').on('click', '#btnSelfAssignTask', function (e) {
 
    //Ajax to return the current user's ID from the controller
    $.ajax({
        url: $(e.currentTarget).data("user-id-url"),
        type: "POST",
        cache: false,
        contentType: "application/json; charset=utf-8",
        success: function (response) {
            var userId = response;

            //Set the value of the dropdown based on the user's id
            var ddAssignee = $('#ddTaskAssignee').data('kendoDropDownList');
            var assigneeDataSource = ddAssignee.dataSource.view(); //For testing
            //TODO improve logic
            ddAssignee.select(function (dataItem) {
                return dataItem.AssigneeTypeFK == 1 && dataItem.AssigneeFK == userId;
            });
        },
        error: function (jqXHR, exception) {
            if (jqXHR.statusText !== 'abort') {
                $('#kNotification').data('kendoNotification').error("An error occurred while assigning task");
            }
        }
    });

});

[Georgi Denchev]

Hello, Anna,

Thank you for the provided details.

Based on the described issue, my guess is that the data hasn't finished binding when you attempt to select the item. This is also why the view is logged as empty.

Try to execute the select logic inside a dataBound event and see if that makes a difference:

        let dd = $("#ddTaskAssignee").data("kendoDropDownList");
        // Bind the databound event to the DropDownList once.
        dd.one("dataBound", () => {
          // Log the view to check the data.
          console.log(dd.dataSource.view())
          
          // Call the select method.
          dd.select(function()...);
        });
        // Set the dataSource.
        dd.setDataSource(ds);

Dojo

https://dojo.telerik.com/@gdenchev/ILEMAtoV 

Best Regards,
Georgi Denchev
Progress Telerik

[Anna]

That worked. Thank you so much!