Maintain record index in Angular Gantt component

17 May 202511 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.

import { Component, ViewEncapsulation, OnInit } from '@angular/core';
import { ganttData } from './data';
import { Gantt } from '@syncfusion/ej2-gantt';

@Component({
    selector: 'app-root',
    template:
       `<ejs-gantt id="ganttDefault" height="450px" [dataSource]="data" [allowRowDragAndDrop]='true'
       [taskFields]="taskSettings"></ejs-gantt>`,
    encapsulation: ViewEncapsulation.None
})
export class AppComponent{
    public data: DataManager;
    public taskSettings: object;
    public ngOnInit(): void {
         this.data = new DataManager({
            url: 'https://localhost:44379/Home/UrlDatasource',
            adaptor: new UrlAdaptor,
            crossDomain: true,
            batchUrl: 'https://localhost:44379/Home/BatchUpdate'
        });
        this.taskSettings = {
            id: 'TaskID',
            name: 'TaskName',
            startDate: 'StartDate',
            duration: 'Duration',
            progress: 'Progress',
            dependency: 'Predecessor',
            child: 'subtasks'
        };
    }
    public rowDrop: function (args) {
        public record = this.flatData[args.fromIndex][this.taskFields.id];
        public record2 = this.flatData[args.dropIndex][this.taskFields.id];
        public data: IGanttData = args.data[0];
        public uri = 'https://localhost:44379/Home/RowDropMethod';
        public dragdropdata = {
             record: data[0].taskData,
             position: args.dropIndex,
             dragidMapping: record,
             dropidMapping: record2
        };
        public ajax = new Ajax(
        {
            url: uri,
            type: 'POST',
            contentType: "application/json",
            data: JSON.stringify(dragdropdata),
        });
        ajax.send();
     };
}

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 });
        }