Updating row drag and dropped index position on server side

17 Feb 202210 minutes to read

Row dropped record’s index position can be maintained in the Gantt chart by changing the database table index position using the rowDrop event. In this event, the fromIndex and dropIndex values can be passed to the server side using Ajax request. On the server side, the insert and insertAtTop methods are used to update the row index position. The following code snippets explain the solution.

CSHTML

<ejs-gantt id='DragAndDrop' height="450px" allowRowDragAndDrop="true" highlightWeekends="true" treeColumnIndex="1">
    <e-data-manager url="https://localhost:44379/Home/UrlDatasource" adaptor="UrlAdaptor" batchUrl="https://localhost:44379/Home/BatchUpdate"></e-data-manager>
    <e-gantt-taskfields id="TaskId" name="TaskName" startDate="StartDate" endDate="EndDate" duration="Duration" progress="Progress" dependency="Predecessor"
                        child="SubTasks">
    </e-gantt-taskfields>
</ejs-gantt>

<script>
    function rowDrop(args) {
        var record = this.flatData[args.fromIndex][this.taskFields.id];
        var record2 = this.flatData[args.dropIndex][this.taskFields.id];
        var data = args.data[0];
        var uri = 'https://localhost:44379/Home/RowDropMethod';
        var dragdropdata = {
            record: data[0].taskData,
            position: args.dropIndex,
            dragidMapping: record,
            dropidMapping: record2
        };
        var ajax = new Ajax(
            {
                url: uri,
                type: 'POST',
                contentType: "application/json",
                data: JSON.stringify(dragdropdata),
            });
        ajax.send();
    }
</script>

Maintainrecordindex.cs

public IActionResult RowDropMethod([FromBody]DragDropData value)
        {
            var data = new CRUDModel();
            copyRecord = true;
            if (value.position == "bottomSegment" || value.position == "topSegment")
            {
                {
                    var childCount = 0;
                    int parent1 = (int)value.record.parentID;
                    childCount += FindChildRecords(parent1);
                    if (childCount == 1)
                    {
                        var i = 0;
                        for (; i < DataList.Count; i++)
                        {
                            if (DataList[i].taskID == parent1)
                            {
                                DataList[i].isParent = false;
                                break;
                            }
                            if (DataList[i].taskID == value.record.taskID)
                            {
                                DataList[i].parentID = null;
                                break;
                            }


                        }
                    }
                }
                DataList.Remove(DataList.Where(ds => ds.taskID == value.dragidMapping).FirstOrDefault());
                var j = 0;
                for (; j < DataList.Count; j++)
                {
                    if (DataList[j].taskID == value.dropidMapping)
                    {
                        value.record.parentID = DataList[j].parentID;
                        break;
                    }
                }

                data.Value = value.record;
                if (value.position == "bottomSegment")
                {
                    this.Insert(data, value.dropidMapping);
                }
                else if (value.position == "topSegment")
                {
                    this.InsertAtTop(data, value.dropidMapping);
                }
            }
            else if (value.position == "middleSegment")
            {
                DataList.Remove(DataList.Where(ds => ds.taskID == value.dragidMapping).FirstOrDefault());
                value.record.parentID = value.dropidMapping;
                FindDropdata(value.dropidMapping);
                data.Value = value.record;
                this.Insert(data, value.dropidMapping);
            }
            copyRecord = false;
            return Json(new { updatedRecords = value.record });
        }