ITask

The ITask interface defines the shape of a task object in SVAR Svelte Gantt. Tasks are the primary data unit rendered as bars on the Gantt chart.

TypeScript definition

export interface ITask {
  id?: TID;
  start?: Date;
  end?: Date;
  duration?: number;
  text?: string;
  details?: string;
  progress?: number;
  type?: TTaskType;
  parent?: TID;
  open?: boolean;
  data?: ITask[];
  base_start?: Date;
  base_end?: Date;
  base_duration?: number;
  rollup?: boolean;
  unscheduled?: boolean;
  segments?: Partial<ITask>[];
  [key: string]: any;
}

export type TTaskType = "task" | "summary" | "milestone" | string;
export type TID = string | number;

Fields

string | number

Unique identifier for the task. Auto-generated if not provided when adding a task via api.exec("add-task", ...).

Date

The start date of the task. Provide a JavaScript Date object. Required unless the task is unscheduled.

Date

The end date of the task. If omitted, it is calculated from start and duration.

number

The task duration in durationUnit units (days by default). If both end and duration are provided, end takes precedence and duration is recalculated.

string

The display label rendered on the task bar and in the grid Name column.

string

Additional descriptive text shown in the task editor. Not rendered on the chart directly.

number

Task completion percentage, from 0 to 100. Rendered as a filled portion of the task bar.

'task' | 'summary' | 'milestone' | string

default:"task"

The task type. Built-in values:

"task" — regular task bar
"summary" — parent group bar that spans its children
"milestone" — zero-duration diamond marker

You can register custom types via the taskTypes config prop.

string | number

ID of the parent task. Set to 0 or omit for root-level tasks. Used to build the task hierarchy.

boolean

default:"false"

Whether the task’s subtree is expanded. Only relevant for tasks with children (type: "summary").

ITask[]

Inline array of child task objects. An alternative to using parent references. When present, the task is treated as a summary.

Date

Baseline start date used when the baselines PRO feature is enabled. Renders a secondary bar showing the original planned schedule.

Date

Baseline end date. Used alongside base_start when the baselines feature is enabled.

number

Baseline duration. Calculated automatically if base_start and base_end are provided.

boolean

When true, this task is displayed as a rollup bar inside its parent summary task. Requires the rollups config option to be enabled.

boolean

When true, the task has no scheduled dates and is shown in the unscheduled tasks area. Requires the unscheduledTasks PRO config option.

Partial<ITask>[]

Array of sub-task segments for split tasks. Each segment is a partial ITask with start, end, and duration. Requires the splitTasks PRO config option.

Example task objects

Regular task
Summary task with children
Milestone
With baseline (PRO)

const task: ITask = {
  id: 1,
  text: "Design phase",
  start: new Date("2024-03-01"),
  end: new Date("2024-03-15"),
  progress: 60,
  type: "task",
  parent: 0
};

const summary: ITask = {
  id: 10,
  text: "Phase 1",
  type: "summary",
  open: true,
  data: [
    {
      id: 11,
      text: "Research",
      start: new Date("2024-03-01"),
      duration: 5
    },
    {
      id: 12,
      text: "Planning",
      start: new Date("2024-03-06"),
      duration: 5
    }
  ]
};

const milestone: ITask = {
  id: 20,
  text: "Launch",
  start: new Date("2024-04-01"),
  type: "milestone"
};

const taskWithBaseline: ITask = {
  id: 30,
  text: "Development",
  start: new Date("2024-03-10"),
  end: new Date("2024-03-25"),
  base_start: new Date("2024-03-08"),
  base_end: new Date("2024-03-22")
};

You can attach arbitrary custom fields to any task object (the interface includes [key: string]: any). Custom fields are accessible in column templates and the task editor.

Components

Data Types

API Object

Data Provider

TypeScript definition

Fields

Example task objects

​TypeScript definition

​Fields

​Example task objects

TypeScript definition

Fields

Example task objects