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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.

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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;

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Fields

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id
string | number
Unique identifier for the task. Auto-generated if not provided when adding a task via api.exec("add-task", ...).
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start
Date
The start date of the task. Provide a JavaScript Date object. Required unless the task is unscheduled.
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end
Date
The end date of the task. If omitted, it is calculated from start and duration.
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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.
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text
string
The display label rendered on the task bar and in the grid Name column.
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details
string
Additional descriptive text shown in the task editor. Not rendered on the chart directly.
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progress
number
Task completion percentage, from 0 to 100. Rendered as a filled portion of the task bar.
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type
'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.
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parent
string | number
ID of the parent task. Set to 0 or omit for root-level tasks. Used to build the task hierarchy.
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open
boolean
default:"false"
Whether the task’s subtree is expanded. Only relevant for tasks with children (type: "summary").
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data
ITask[]
Inline array of child task objects. An alternative to using parent references. When present, the task is treated as a summary.
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base_start
Date
Baseline start date used when the baselines PRO feature is enabled. Renders a secondary bar showing the original planned schedule.
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base_end
Date
Baseline end date. Used alongside base_start when the baselines feature is enabled.
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base_duration
number
Baseline duration. Calculated automatically if base_start and base_end are provided.
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rollup
boolean
When true, this task is displayed as a rollup bar inside its parent summary task. Requires the rollups config option to be enabled.
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unscheduled
boolean
When true, the task has no scheduled dates and is shown in the unscheduled tasks area. Requires the unscheduledTasks PRO config option.
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segments
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.

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Example task objects

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
};
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.

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