Virtualization in Blazor Gantt Chart Component

4 Aug 202124 minutes to read

Gantt Chart allows you to load a large amount of data without performance degradation.

Row Virtualization

Row virtualization allows you to render rows only in the content viewport on load time. It is an alternative way of paging in which the rows will be loaded while scrolling vertically. To set up the row virtualization, you need to define EnableVirtualization as true and content height by Height property.

The number of records displayed in the Gantt Chart is determined implicitly by the height of the content area.

namespace GanttComponent.Data
{
    public class GanttData
    {
        public class GanttDataSource
        {
            public int TaskId { get; set; }
            public string TaskName { get; set; }
            public DateTime StartDate { get; set; }
            public DateTime EndDate { get; set; }
            public string Duration { get; set; }
            public string Predecessor { get; set; }
            public int Progress { get; set; }
            public int? ParentID { get; set; }

        }

        public static List<GanttDataSource> VirtualData()
        {
            List<GanttDataSource> list = new List<GanttDataSource>();
            for (var i = 0; i < 2; i++)
            {
                var x = list.Count + 1;
                list.Add(new GanttDataSource()
                {
                    TaskId = x,
                    TaskName = "Project " + (i + 1)
                });
                for (var j = 0; j < TempData().ToList().Count; j++)
                {
                    list.Add(new GanttDataSource()
                    {
                        TaskId = TempData()[j].TaskId + x,
                        TaskName = TempData()[j].TaskName,
                        StartDate = TempData()[j].StartDate,
                        Duration = TempData()[j].Duration,
                        Progress = TempData()[j].Progress,
                        ParentID = TempData()[j].ParentID + x
                    });
                }
            }
            return list;
        }
        public static List<GanttDataSource> TempData()
        {
            List<GanttDataSource> GanttDataSourceCollection = new List<GanttDataSource>();

            GanttDataSource Record1 = new GanttDataSource()
            {
                TaskId = 1,
                TaskName = "Product concept",
                StartDate = new DateTime(2019, 04, 02),
                EndDate = new DateTime(2019, 04, 29),
                ParentID = 0
            };
            GanttDataSource Record2 = new GanttDataSource()
            {
                TaskId = 2,
                TaskName = "Defining the product and its usage",
                StartDate = new DateTime(2019, 04, 02),
                Duration = "3",
                Progress = 30,
                ParentID = 1,
            };
            GanttDataSource Record3 = new GanttDataSource()
            {
                TaskId = 3,
                TaskName = "Defining target audience",
                StartDate = new DateTime(2019, 04, 02),
                ParentID = 1,
                Duration = "3"
            };
            GanttDataSource Record4 = new GanttDataSource()
            {
                TaskId = 4,
                TaskName = "Prepare product sketch and notes",
                StartDate = new DateTime(2019, 04, 05),
                Duration = "2",
                ParentID = 1,
                Predecessor = "2",
                Progress = 30
            };
            GanttDataSource Record5 = new GanttDataSource()
            {
                TaskId = 5,
                TaskName = "Concept approval",
                StartDate = new DateTime(2019, 04, 08),
                ParentID = 0,
                Duration = "0",
                Predecessor = "3,4"
            };
            GanttDataSource Record6 = new GanttDataSource()
            {
                TaskId = 6,
                TaskName = "Market research",
                StartDate = new DateTime(2019, 04, 02),
                ParentID = 0,
                EndDate = new DateTime(2019, 04, 21),
            };
            GanttDataSource Record7 = new GanttDataSource()
            {
                TaskId = 7,
                TaskName = "Demand analysis",
                StartDate = new DateTime(2019, 04, 04),
                EndDate = new DateTime(2019, 04, 21),
                ParentID = 6,
            };
            GanttDataSource Record8 = new GanttDataSource()
            {
                TaskId = 8,
                TaskName = "Customer strength",
                StartDate = new DateTime(2019, 04, 09),
                Duration = "4",
                Predecessor = "5",
                ParentID = 7,
                Progress = 30
            };
            GanttDataSource Record9 = new GanttDataSource()
            {
                TaskId = 9,
                TaskName = "Market opportunity analysis",
                StartDate = new DateTime(2019, 04, 9),
                Duration = "4",
                ParentID = 7,
                Predecessor = "5"
            };
            GanttDataSource Record10 = new GanttDataSource()
            {
                TaskId = 10,
                TaskName = "Competitor analysis",
                StartDate = new DateTime(2019, 04, 15),
                Duration = "4",
                Predecessor = "7, 8",
                ParentID = 6,
                Progress = 30
            };
            GanttDataSource Record11 = new GanttDataSource()
            {
                TaskId = 11,
                TaskName = "Product strength analsysis",
                StartDate = new DateTime(2019, 04, 15),
                Duration = "4",
                ParentID = 6,
                Predecessor = "9"
            };
            GanttDataSource Record12 = new GanttDataSource()
            {
                TaskId = 12,
                TaskName = "Research complete",
                StartDate = new DateTime(2019, 04, 18),
                Duration = "0",
                ParentID = 6,
                Predecessor = "10"
            };
            GanttDataSource Record13 = new GanttDataSource()
            {
                TaskId = 13,
                TaskName = "Product design and development",
                StartDate = new DateTime(2019, 04, 04),
                ParentID = 0,
                EndDate = new DateTime(2019, 04, 21),
            };
            GanttDataSource Record14 = new GanttDataSource()
            {
                TaskId = 14,
                TaskName = "Functionality design",
                StartDate = new DateTime(2019, 04, 19),
                Duration = "3",
                ParentID = 13,
                Progress = 30,
                Predecessor = "12"
            };
            GanttDataSource Record15 = new GanttDataSource()
            {
                TaskId = 15,
                TaskName = "Quality design",
                StartDate = new DateTime(2019, 04, 19),
                Duration = "3",
                ParentID = 13,
                Predecessor = "12"
            };
            GanttDataSource Record16 = new GanttDataSource()
            {
                TaskId = 16,
                TaskName = "Define reliability",
                StartDate = new DateTime(2019, 04, 24),
                Duration = "2",
                Progress = 30,
                ParentID = 13,
                Predecessor = "15"
            };
            GanttDataSource Record17 = new GanttDataSource()
            {
                TaskId = 17,
                TaskName = "Identifying raw materials",
                StartDate = new DateTime(2019, 04, 24),
                Duration = "2",
                ParentID = 13,
                Predecessor = "15"
            };
            GanttDataSource Record18 = new GanttDataSource()
            {
                TaskId = 18,
                TaskName = "Define cost plan",
                StartDate = new DateTime(2019, 04, 04),
                ParentID = 13,
                EndDate = new DateTime(2019, 04, 21),
            };
            GanttDataSource Record19 = new GanttDataSource()
            {
                TaskId = 19,
                TaskName = "Manufacturing cost",
                StartDate = new DateTime(2019, 04, 26),
                Duration = "2",
                Progress = 30,
                ParentID = 18,
                Predecessor = "17"
            };
            GanttDataSource Record20 = new GanttDataSource()
            {
                TaskId = 20,
                TaskName = "Selling cost",
                StartDate = new DateTime(2019, 04, 26),
                Duration = "2",
                ParentID = 18,
                Predecessor = "17"
            };
            GanttDataSource Record21 = new GanttDataSource()
            {
                TaskId = 21,
                TaskName = "Development of the final design",
                StartDate = new DateTime(2019, 04, 30),
                ParentID = 13,
                EndDate = new DateTime(2019, 04, 21),
            };
            GanttDataSource Record22 = new GanttDataSource()
            {
                TaskId = 22,
                TaskName = "Defining dimensions and package volume",
                StartDate = new DateTime(2019, 04, 30),
                Duration = "2",
                ParentID = 21,
                Progress = 30,
                Predecessor = "19,20"
            };
            GanttDataSource Record23 = new GanttDataSource()
            {
                TaskId = 23,
                TaskName = "Develop design to meet industry standards",
                StartDate = new DateTime(2019, 05, 02),
                Duration = "2",
                ParentID = 21,
                Predecessor = "22"
            };
            GanttDataSource Record24 = new GanttDataSource()
            {
                TaskId = 24,
                TaskName = "Include all the details",
                StartDate = new DateTime(2019, 05, 06),
                Duration = "3",
                ParentID = 21,
                Predecessor = "23"
            };
            GanttDataSource Record25 = new GanttDataSource()
            {
                TaskId = 25,
                TaskName = "CAD computer-aided design",
                StartDate = new DateTime(2019, 05, 09),
                Duration = "3",
                ParentID = 13,
                Progress = 30,
                Predecessor = "24"
            };
            GanttDataSource Record26 = new GanttDataSource()
            {
                TaskId = 26,
                TaskName = "CAM computer-aided manufacturing",
                StartDate = new DateTime(2019, 05, 14),
                Duration = "3",
                ParentID = 13,
                Predecessor = "25"
            };
            GanttDataSource Record27 = new GanttDataSource()
            {
                TaskId = 27,
                TaskName = "Design complete",
                StartDate = new DateTime(2019, 05, 16),
                Duration = "0",
                ParentID = 13,
                Predecessor = "26"
            };
            GanttDataSource Record28 = new GanttDataSource()
            {
                TaskId = 28,
                TaskName = "Prototype testing",
                StartDate = new DateTime(2019, 05, 17),
                Duration = "4",
                Progress = 30,
                ParentID = 0,
                Predecessor = "27"
            };
            GanttDataSource Record29 = new GanttDataSource()
            {
                TaskId = 29,
                TaskName = "Include feedback",
                StartDate = new DateTime(2019, 05, 17),
                Duration = "4",
                ParentID = 0,
                Predecessor = "28ss"
            };
            GanttDataSource Record30 = new GanttDataSource()
            {
                TaskId = 30,
                TaskName = "Manufacturing",
                StartDate = new DateTime(2019, 05, 23),
                Duration = "5",
                Progress = 30,
                ParentID = 0,
                Predecessor = "28,29"
            };
            GanttDataSource Record31 = new GanttDataSource()
            {
                TaskId = 31,
                TaskName = "Assembling materials to finsihed goods",
                StartDate = new DateTime(2019, 05, 30),
                Duration = "5",
                ParentID = 0,
                Predecessor = "30"
            };
            GanttDataSource Record32 = new GanttDataSource()
            {
                TaskId = 32,
                TaskName = "Feedback and testing",
                StartDate = new DateTime(2019, 05, 04),
                ParentID = 0,
                EndDate = new DateTime(2019, 05, 21),
            };
            GanttDataSource Record33 = new GanttDataSource()
            {
                TaskId = 33,
                TaskName = "Internal testing and feedback",
                StartDate = new DateTime(2019, 06, 06),
                Duration = "3",
                ParentID = 32,
                Progress = 45,
                Predecessor = "31"
            };
            GanttDataSource Record34 = new GanttDataSource()
            {
                TaskId = 34,
                TaskName = "Customer testing and feedback",
                StartDate = new DateTime(2019, 06, 11),
                Duration = "3",
                ParentID = 32,
                Progress = 50,
                Predecessor = "33"
            };
            GanttDataSource Record35 = new GanttDataSource()
            {
                TaskId = 35,
                TaskName = "Final product development",
                StartDate = new DateTime(2019, 06, 06),
                ParentID = 0,
                EndDate = new DateTime(2019, 06, 06),
            };
            GanttDataSource Record36 = new GanttDataSource()
            {
                TaskId = 36,
                TaskName = "Important improvements",
                StartDate = new DateTime(2019, 06, 14),
                Duration = "4",
                Progress = 30,
                ParentID = 35,
                Predecessor = "34"
            };
            GanttDataSource Record37 = new GanttDataSource()
            {
                TaskId = 37,
                TaskName = "Address any unforeseen issues",
                StartDate = new DateTime(2019, 06, 14),
                Duration = "4",
                Progress = 30,
                ParentID = 35,
                Predecessor = "36ss"
            };
            GanttDataSource Record38 = new GanttDataSource()
            {
                TaskId = 38,
                TaskName = "Final product",
                StartDate = new DateTime(2019, 06, 06),
                ParentID = 0,
                EndDate = new DateTime(2019, 06, 06),
            };
            GanttDataSource Record39 = new GanttDataSource()
            {
                TaskId = 39,
                TaskName = "Branding product",
                StartDate = new DateTime(2019, 06, 20),
                Duration = "4",
                ParentID = 38,
                Predecessor = "37"
            };
            GanttDataSource Record40 = new GanttDataSource()
            {
                TaskId = 40,
                TaskName = "Marketing and presales",
                StartDate = new DateTime(2019, 06, 26),
                Duration = "4",
                Progress = 30,
                ParentID = 38,
                Predecessor = "39"
            };
            GanttDataSourceCollection.Add(Record1);
            GanttDataSourceCollection.Add(Record2);
            GanttDataSourceCollection.Add(Record3);
            GanttDataSourceCollection.Add(Record4);
            GanttDataSourceCollection.Add(Record5);
            GanttDataSourceCollection.Add(Record6);
            GanttDataSourceCollection.Add(Record7);
            GanttDataSourceCollection.Add(Record8);
            GanttDataSourceCollection.Add(Record9);
            GanttDataSourceCollection.Add(Record10);
            GanttDataSourceCollection.Add(Record11);
            GanttDataSourceCollection.Add(Record12);
            GanttDataSourceCollection.Add(Record13);
            GanttDataSourceCollection.Add(Record14);
            GanttDataSourceCollection.Add(Record15);
            GanttDataSourceCollection.Add(Record16);
            GanttDataSourceCollection.Add(Record17);
            GanttDataSourceCollection.Add(Record18);
            GanttDataSourceCollection.Add(Record19);
            GanttDataSourceCollection.Add(Record20);
            GanttDataSourceCollection.Add(Record21);
            GanttDataSourceCollection.Add(Record22);
            GanttDataSourceCollection.Add(Record23);
            GanttDataSourceCollection.Add(Record24);
            GanttDataSourceCollection.Add(Record25);
            GanttDataSourceCollection.Add(Record26);
            GanttDataSourceCollection.Add(Record27);
            GanttDataSourceCollection.Add(Record28);
            GanttDataSourceCollection.Add(Record29);
            GanttDataSourceCollection.Add(Record30);
            GanttDataSourceCollection.Add(Record31);
            GanttDataSourceCollection.Add(Record32);
            GanttDataSourceCollection.Add(Record33);
            GanttDataSourceCollection.Add(Record34);
            GanttDataSourceCollection.Add(Record35);
            GanttDataSourceCollection.Add(Record36);
            GanttDataSourceCollection.Add(Record37);
            GanttDataSourceCollection.Add(Record38);
            GanttDataSourceCollection.Add(Record39);
            GanttDataSourceCollection.Add(Record40);
            return GanttDataSourceCollection;
        }
    }
}

Limitations for Virtualization

  • Due to the element height limitation in browsers, the maximum number of records loaded by the Gantt chart is limited by the browser capability.
  • It is necessary to mention the height of the Gantt in pixels when enabling Virtual Scrolling.
  • Cell selection will not be persisted in a row.
  • Programmatic selection using the SelectRows method is not supported in virtual scrolling.
  • Currently Editing, Row Drag and Drop are not supported with Virtual scrolling.