Blazorise Gantt: Data Binding

Bind Gantt to your own task model through configurable field mappings.

Data Model

Gantt<TItem> binds to your own model type through field mapping parameters such as IdField, StartField, and EndField. You can keep your existing model names and map them without creating a dedicated DTO.

Must-Have Fields

For most production scenarios, these are the fields you should map:

  • StartField and EndField: Required to render timeline bars. If either value is missing/unassigned, the item cannot be drawn on the timeline.
  • TitleField: Recommended for readable tree rows and task labels.
  • IdField: Strongly recommended for stable identity, selection/state behavior, and CRUD operations.
  • DurationField (optional): Used for duration column/editing. If not mapped, duration is calculated from StartField and EndField.
  • ProgressField (optional): Enables progress percentage in bars, columns, and the edit dialog slider.

Flat vs Hierarchical Data

Gantt supports both data shapes:

  • Flat data: One collection with IdField and ParentIdField. This is usually best for API-driven data.
  • Hierarchical data: Nested child collections mapped through ItemsField.
  • If both ParentIdField and ItemsField exist, Gantt uses flat mode by default. Set HierarchicalData="true" to force hierarchical mode.
  • If ItemsField exists and ParentIdField does not, hierarchical mode is used automatically.

Flat Data Binding

Use the classic Id + ParentId model when your API already returns a flat task list.
Aug 10 - Aug 16, 2026
Task
Start
Website redesign
Aug 11, 2026
Discovery
Aug 11, 2026
Implementation
Aug 15, 2026
Components
Aug 16, 2026
Accessibility pass
Aug 21, 2026
Launch
Aug 25, 2026
Mon 10
Tue 11
Wed 12
Thu 13
Fri 14
Sat 15
Sun 16
Website redesign
Discovery
Implementation
Components
<Gantt TItem="TaskItem"
       Data="@tasks"
       Date="@selectedDate"
       SelectedView="GanttView.Week"
       DurationField="Duration">
    <GanttColumns>
        <GanttColumn Field="Title" Title="Task" Expandable Width="Width.Px(220)" />
        <GanttColumn Field="Start" Width="Width.Px(130)" />
        <GanttColumn Field="End" Width="Width.Px(130)" Visible="false" />
        <GanttColumn Field="Duration" Width="Width.Px(90)" TextAlignment="TextAlignment.Center" Visible="false" />
    </GanttColumns>
    <GanttToolbar />
    <GanttViews>
        <GanttWeekView TimelineCellWidth="90" RowHeight="44" />
    </GanttViews>
</Gantt>

@code {
    private DateOnly selectedDate = DateOnly.FromDateTime( DateTime.Today );

    private List<TaskItem> tasks = CreateTasks();

    private static List<TaskItem> CreateTasks()
    {
        var baseDate = DateTime.Today.AddDays( -2 );

        var result = new List<TaskItem>
        {
            new() { Id = "1", Title = "Website redesign", Start = baseDate, End = baseDate.AddDays( 16 ) },
            new() { Id = "2", ParentId = "1", Title = "Discovery", Start = baseDate, End = baseDate.AddDays( 4 ) },
            new() { Id = "3", ParentId = "1", Title = "Implementation", Start = baseDate.AddDays( 4 ), End = baseDate.AddDays( 14 ) },
            new() { Id = "4", ParentId = "3", Title = "Components", Start = baseDate.AddDays( 5 ), End = baseDate.AddDays( 10 ) },
            new() { Id = "5", ParentId = "3", Title = "Accessibility pass", Start = baseDate.AddDays( 10 ), End = baseDate.AddDays( 13 ) },
            new() { Id = "6", ParentId = "1", Title = "Launch", Start = baseDate.AddDays( 14 ), End = baseDate.AddDays( 16 ) },
        };

        foreach ( var item in result )
        {
            item.Duration = Math.Max( 1, (int)Math.Ceiling( ( item.End - item.Start ).TotalDays ) );
        }

        return result;
    }

    public class TaskItem
    {
        public string Id { get; set; }

        public string ParentId { get; set; }

        public string Title { get; set; }

        public DateTime Start { get; set; }

        public DateTime End { get; set; }

        public int Duration { get; set; }
    }
}

Hierarchical Data Binding

Bind directly to nested task collections with ItemsField for tree-shaped data models.
Aug 10 - Aug 16, 2026
WBS
Task
Start
1
Mobile app release
Aug 11, 2026
1.1
Planning
Aug 11, 2026
1.2
Execution
Aug 15, 2026
1.2.1
API integration
Aug 16, 2026
1.2.2
QA
Aug 22, 2026
1.3
Go-live
Aug 27, 2026
Mon 10
Tue 11
Wed 12
Thu 13
Fri 14
Sat 15
Sun 16
Mobile app release
Planning
Execution
API integration
<Gantt TItem="TaskItem"
       Data="@tasks"
       Date="@selectedDate"
       SelectedView="GanttView.Week"
       ItemsField="Children"
       HierarchicalData
       DurationField="Duration">
    <GanttColumns>
        <GanttColumn Field="Wbs" Width="Width.Px(76)" TextAlignment="TextAlignment.Center" Visible="false" />
        <GanttColumn Field="Title" Title="Task" Expandable Width="Width.Px(220)" />
        <GanttColumn Field="Start" Width="Width.Px(130)" />
        <GanttColumn Field="End" Width="Width.Px(130)" Visible="false" />
        <GanttColumn Field="Duration" Width="Width.Px(90)" TextAlignment="TextAlignment.Center" Visible="false" />
    </GanttColumns>
    <GanttToolbar />
    <GanttViews>
        <GanttWeekView TimelineCellWidth="90" RowHeight="44" />
    </GanttViews>
</Gantt>

@code {
    private DateOnly selectedDate = DateOnly.FromDateTime( DateTime.Today );

    private List<TaskItem> tasks = CreateTasks();

    private static List<TaskItem> CreateTasks()
    {
        var baseDate = DateTime.Today.AddDays( -2 );

        var result = new List<TaskItem>
        {
            new()
            {
                Id = "1",
                Title = "Mobile app release",
                Start = baseDate,
                End = baseDate.AddDays( 18 ),
                Children = new()
                {
                    new()
                    {
                        Id = "2",
                        Title = "Planning",
                        Start = baseDate,
                        End = baseDate.AddDays( 4 ),
                    },
                    new()
                    {
                        Id = "3",
                        Title = "Execution",
                        Start = baseDate.AddDays( 4 ),
                        End = baseDate.AddDays( 16 ),
                        Children = new()
                        {
                            new()
                            {
                                Id = "4",
                                Title = "API integration",
                                Start = baseDate.AddDays( 5 ),
                                End = baseDate.AddDays( 11 ),
                            },
                            new()
                            {
                                Id = "5",
                                Title = "QA",
                                Start = baseDate.AddDays( 11 ),
                                End = baseDate.AddDays( 16 ),
                            },
                        },
                    },
                    new()
                    {
                        Id = "6",
                        Title = "Go-live",
                        Start = baseDate.AddDays( 16 ),
                        End = baseDate.AddDays( 18 ),
                    },
                },
            },
        };

        UpdateDuration( result );

        return result;
    }

    private static void UpdateDuration( IEnumerable<TaskItem> items )
    {
        foreach ( var item in items )
        {
            item.Duration = Math.Max( 1, (int)Math.Ceiling( ( item.End - item.Start ).TotalDays ) );
            UpdateDuration( item.Children );
        }
    }

    public class TaskItem
    {
        public string Id { get; set; }

        public string Title { get; set; }

        public DateTime Start { get; set; }

        public DateTime End { get; set; }

        public int Duration { get; set; }

        public List<TaskItem> Children { get; set; } = new();
    }
}

API

See the documentation below for a complete reference to all of the props and classes available to the components mentioned here.

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