API Reference

For full TypeScript definitions and detailed signatures, see the generated API documentation.

Properties

list: TaskList	All tasks and links (read-only).
resources: ResourceList	All resources (read-only).
sheet: GanttSheet	The sheet (table) component (read-only).
selectedTasks: Task[]	Currently selected tasks (read-only).
locale: TimelineKitLocale	Shorthand for settings.locale.
settings: GanttChartSettings	Settings object — access theme, locale, currency (read-only).
events: GanttChartEvents	Event emitters (read-only).
canEdit: boolean	Enable/disable editing. Default: true.
autoZoomToFit: boolean	Automatically zoom to fit when projectTimeline is set or data is loaded. Default: true.
showGridLines: boolean	Show/hide grid lines on the chart. Default: true.
showCriticalPath: boolean	Enable/disable critical path highlighting. Default: false.
showBaseline: boolean	Show/hide baseline overlay. Default: false.
showTodayLine: boolean	Show/hide today indicator line. Default: true.
allowTaskSplitting: boolean	Allow splitting tasks into multiple parts via mouse. Default: true.
hasBaseline: boolean	Whether a baseline has been saved (read-only).
markers: Marker[]	Timeline markers.
filter: TaskFilterFn \| null	Active task filter function.
projectTimeline: DateRange	Project start/end date bounds.
workingCalendar: WorkingCalendar	Working calendar (get/set).
canUndo$: BehaviorSubject<boolean>	Whether undo is available (observable, read-only).
canRedo$: BehaviorSubject<boolean>	Whether redo is available (observable, read-only).

Methods

load(json: string): void	Load data from a JSON string.
save(): string	Serialize current state to a JSON string.
zoomIn(): boolean	Zoom in. Returns false if already at max zoom.
zoomOut(): boolean	Zoom out. Returns false if already at min zoom.
zoomToFit(tasks?: Task[]): void	Fit the view to show all (or specified) tasks.
scrollToDate(date: Date): void	Scroll the timeline to a specific date.
scrollToTask(task: Task): void	Scroll to make a task visible (horizontal + vertical).
goToProjectStart(): void	Scroll to the project start date.
indent(): void	Indent selected tasks (make subtasks).
outdent(): void	Outdent selected tasks (promote level).
moveUp(): void	Move selected tasks up.
moveDown(): void	Move selected tasks down.
undo(): void	Undo the last action.
redo(): void	Redo the last undone action.
copy(): Promise<void>	Copy selected tasks to clipboard.
cut(): Promise<void>	Cut selected tasks to clipboard.
paste(): Promise<TasksPastedEventArgs \| null>	Paste tasks from clipboard.
addMarker(marker: Marker): void	Add a timeline marker.
removeMarker(marker: Marker): void	Remove a timeline marker.
clearMarkers(): void	Remove all timeline markers.
clearFilter(): void	Clear the active task filter.
saveBaseline(): void	Save current schedule as baseline.
clearBaseline(): void	Clear the saved baseline.
saveColumns(): ColumnState[]	Save column layout (widths, order, visibility).
loadColumns(states: ColumnState[]): void	Restore column layout.
exportToImage(): Promise<Blob>	Export chart as PNG.
exportToCsv(options?: GanttCsvExportOptions): string	Export as CSV string.
exportToPdf(options?: GanttPdfExportOptions): Promise<Blob>	Export as PDF (requires jspdf).
exportToExcel(options?: GanttExcelExportOptions): Promise<Blob>	Export as Excel (requires exceljs).
destroy(): void	Destroy the chart and release all DOM resources. Called automatically in React and Angular; required for vanilla/direct core usage.

TaskList Methods

Available via gantt.list.

createTask(id?: string): Task	Create a new Task wired to the chart's calendar and project timeline, without adding it to the list. Use addTask() to insert it.
addTask(task: Task): Task	Add a task to the end of the list.
insertTask(index: number, task: Task): Task	Insert a task at a specific position.
addEmptyTask(): Task	Append an empty placeholder row at the end.
insertEmptyTask(index: number): Task	Insert an empty placeholder row at a specific position.
getTask(index: number): Task	Get a task by flat index.
getTaskById(id: string): Task \| null	Find a task by ID.
length: number	Total number of tasks (read-only).
removeTask(task: Task): void	Remove a single task.
removeTasks(tasks: Task[]): void	Remove multiple tasks.
clear(): void	Remove all tasks and links.
addLink(from: Task, to: Task, type: TaskLinkType, lag?: Lag): TaskLink	Add a dependency link.
removeLink(link: TaskLink): void	Remove a dependency link.
existsLinkBetween(from: Task, to: Task): boolean	Check if a link already exists.
wouldCreateCycle(from: Task, to: Task): boolean	Check if adding a link would create a cycle.
getTasksUsingResource(resource: Resource): Task[]	Find all tasks assigned to a resource.
indent(tasks: Task[]): void	Indent tasks (make subtasks of preceding task).
outdent(tasks: Task[]): void	Outdent tasks (promote one level).
moveUp(tasks: Task[]): void	Move tasks up in the list.
moveDown(tasks: Task[]): void	Move tasks down in the list.

Events

All events are RxJS Subject instances. Subscribe via gantt.events.eventName$.subscribe(callback).

taskAdded$: Subject<TaskEventArgs>	A task was added.
taskChanged$: Subject<TaskEventArgs>	A task property changed.
taskRemoved$: Subject<TaskEventArgs>	A task was removed.
taskClick$: Subject<TaskEventArgs>	A task bar was clicked.
taskDblClick$: Subject<TaskEventArgs>	A task bar was double-clicked.
taskContextMenu$: Subject<TaskContextMenuArgs>	Right-click on task bar.
chartContextMenu$: Subject<ChartContextMenuArgs>	Right-click on chart area.
sheetRowContextMenu$: Subject<TableRowContextMenuEventArgs>	Right-click on sheet row.
sheetColumnHeaderContextMenu$: Subject<TableColumnHeaderEventArgs>	Right-click on column header.
sheetColumnResized$: Subject<TableColumnEventArgs>	A column was resized.
sheetColumnReordered$: Subject<TableColumnEventArgs>	A column was reordered.
sheetCellEditing$: Subject<TableCellEditing \| null>	Cell editing started (payload) or ended (null).
sheetCellDialogEdit$: Subject<DialogEditorArgs>	A cell requires dialog editing (e.g. resources).
sheetCellInputEdit$: Subject<InputEditorArgs>	A cell requires input editing.
sheetCellInvalidValue$: Subject<void>	An invalid value was entered.
linkAdded$: Subject<TaskLinkEventArgs>	A dependency link was added.
linkRemoved$: Subject<TaskLinkEventArgs>	A dependency link was removed.
tasksPasted$: Subject<TasksPastedEventArgs>	Tasks were pasted from clipboard.
projectTimeline$: Subject<DateRange>	Project timeline bounds changed.
undone$: Subject<void>	An undo was performed.
redone$: Subject<void>	A redo was performed.

Types & Enums

Task

A schedulable item in the Gantt chart. Can be a Task, Milestone, Summary, or Empty row.

id: string	Unique identifier (read-only, auto-generated).
name: string \| null	Display name. Setting a name on an Empty row converts it to a Task.
type: TaskType	Current type: 'task' \| 'milestone' \| 'summary' \| 'empty'.
startTime: Date \| null	Start date/time. Computed from subtasks for Summary tasks.
endTime: Date \| null	End date/time. Computed from subtasks for Summary tasks.
length: Length \| null	Computed duration (read-only for Summary). Null for Empty tasks.
customLengthUnit: LengthUnit \| null	Override for the length display unit. When null, the calendar's default unit is used.
progress: number \| null	Completion percentage (0–100). Computed for Summary tasks. Null for Empty/Milestone.
color: ColorValue	Color index into the theme's taskColors array, or a custom ColorDefinition. Default: 0.
note: string \| null	Free-form text note.
parent: Task \| null	Parent summary task (read-only). Null for top-level tasks.
collapsed: boolean	Whether a Summary task's subtasks are collapsed. Default: false.
level: number	Nesting depth (read-only). 0 for top-level, 1 for first-level subtasks, etc.
constraintType: ConstraintType	Scheduling constraint. Default: 'asap'.
constraintDate: Date \| null	Date for the scheduling constraint. Null for ASAP/ALAP.
work: Work \| null	Total work effort. Computed from resources, or set manually when none assigned.
cost: number \| null	Total cost. Computed from resource rates, or set manually.
baselineStartTime: Date \| null	Baseline start time for variance tracking.
baselineEndTime: Date \| null	Baseline end time for variance tracking.
warnings: string[]	Active warning messages (e.g. behind schedule).
filtered: boolean	Whether excluded by the active filter (read-only).
hidden: boolean	Whether hidden (filtered out or inside a collapsed Summary, read-only).
isCritical: boolean	Whether this task is on the critical path (read-only, computed).
earlyStart: Date \| null	CPM early start (read-only, computed).
earlyFinish: Date \| null	CPM early finish (read-only, computed).
lateStart: Date \| null	CPM late start (read-only, computed).
lateFinish: Date \| null	CPM late finish (read-only, computed).
totalFloat: number \| null	Total float in working hours (read-only, computed).
freeFloat: number \| null	Free float in working hours (read-only, computed).

Task also supports custom properties via addProperty(), getPropertyValue(), setPropertyValue(), and removeProperty().

TaskLink

A dependency link between two tasks.

id: string	Unique identifier (read-only).
from: Task	Predecessor task (read-only).
to: Task	Successor task (read-only).
type: TaskLinkType	Dependency type (read-only).
lag: Lag	Time offset applied to the dependency (read-only).

Resource

A named resource (person, equipment, etc.) that can be assigned to tasks.

id: string	Unique identifier (read-only).
name: string	Display name.
type: ResourceType	'unique' \| 'generic'.
rate: Rate \| null	Hourly or daily cost rate.
fixedCostPerUse: number	Fixed cost charged each time this resource is used. Default: 0.
fixedCostPerResource: number	Fixed cost per resource assignment. Default: 0.
avatarIconUrl: string \| null	URL to an avatar image. Default: null.

TaskResource

Assignment of a resource to a task with a capacity percentage.

id: string	Unique identifier (read-only).
resource: Resource	The underlying resource definition (read-only).
capacity: number	Allocation percentage (100 = full-time, 200 = double allocation).

TaskPart

A contiguous time segment of a split task.

startTime: Date	Start date/time of this part.
endTime: Date	End date/time of this part.
length: Length	Duration of this part.

WorkingCalendar

Defines working days, shifts, and holidays for scheduling calculations.

workingDays: DayOfWeek[]	Days of the week that are working days. Default: Mon–Fri.
nationalHolidays: Date[]	Dates that are non-working regardless of the day. Default: [].
shifts: WorkingShift[]	Working time ranges within each day. Default: 8:00–12:00, 13:00–17:00.
startOfWeek: DayOfWeek	First day of the week for calendar display. Default: 'sunday'.
defaultLengthUnit: LengthUnit	Default unit for new task durations. Default: 'day'.

Methods

isWorkingDay(date: Date): boolean	Check whether a date falls on a working day.
getHoursPerDay(): number	Total working hours in a day based on configured shifts.
getHoursBetween(time1: Date, time2: Date): number	Working hours between two dates, respecting shifts and non-working days.
addHours(date: Date, hours: number): Date	Add/subtract working hours, skipping non-working time.

WorkingShift

A working time range within a day (e.g. 8:00–12:00).

start: TimeOfDay	Start time of the shift.
end: TimeOfDay	End time of the shift.

TimeOfDay

A time of day represented as hour and minute.

hour: number	Hour (0–23).
minute: number	Minute (0–59).

DateRange

Project timeline bounds.

startDate: Date	Start date of the range.
endDate: Date	End date of the range.

Length

Represents a task duration with a time unit. Create via Length.parse('5d') or new Length('day', 5).

value: number	Numeric amount (read-only).
unit: LengthUnit	Time unit (read-only).

Static methods

parse(value: string): Length	Parse a length string (e.g. '5d', '2w'). Throws on invalid input.
tryParse(value: string): Length \| null	Parse a length string. Returns null if invalid.
getLength(start: Date, end: Date, unit: LengthUnit, calendar: WorkingCalendar): Length	Calculate duration between two dates.

Lag

Time offset (positive or negative) applied to a dependency link. Create via Lag.parse('+2d').

value: number	Numeric amount — positive = lag, negative = lead (read-only).
unit: LengthUnit	Time unit (read-only).

Static methods

parse(value: string): Lag	Parse a lag string (e.g. '+2d', '-1h'). Throws on invalid input.
tryParse(value: string): Lag \| null	Parse a lag string. Returns null if invalid.
zero(): Lag	Create a zero lag (0 days).

Work

Represents a work effort amount with a time unit. Create via Work.tryParse('40h').

value: number	Numeric amount (read-only).
unit: WorkUnit	Time unit (read-only).

Rate

Cost rate associated with a resource.

value: number	Monetary value of the rate (read-only).
type: RateType	'perDay' \| 'perHour' (read-only).

Marker

A vertical date marker displayed on the chart.

date: Date	Date position of the marker line.
label?: string	Optional text label.
color?: string	CSS color string.
lineWidth?: number	Width of the marker line in pixels.
lineStyle?: 'solid' \| 'dashed' \| 'dotted'	Dash style of the marker line.

CustomProperty

Custom task property (name + value).

name: string	Property name.
value: any	Property value.

GanttChartSettings

Gantt chart settings — theme, locale, and currency configuration.

theme: GanttChartTheme	Current theme.
locale: TimelineKitLocale	Current locale.
currencySymbol: string	Currency symbol used in cost columns. Default: '$'.
currencySymbolDisplayMode: CurrencySymbolDisplayMode	How the currency symbol is positioned relative to the amount. Default: 'beforeAmountWithSpace'.

ColumnState

Saved column layout state.

code: string	Column identifier.
width: number	Column width in pixels.
isVisible: boolean	Whether the column is visible.

ColorDefinition

Custom color definition that can be used instead of a theme color index. All properties except color1 and color2 are optional — unspecified values are inherited from the first theme palette entry.

color1: string	Primary fill color (top of gradient).
color2: string	Secondary fill color (bottom of gradient).
highlightColor?: string	Hover/highlight overlay color.
borderColor?: string \| null	Border color. Null = no border.
progressColor1?: string	Primary progress bar fill color (top of gradient).
progressColor2?: string	Secondary progress bar fill color (bottom of gradient).
progressHighlightColor?: string	Progress bar hover/highlight overlay color.

Event args types

TaskEventArgs

task: Task

The task that triggered the event.

TaskLinkEventArgs

link: TaskLink

The link that was added or removed.

TaskContextMenuArgs

task: Task	The task that was right-clicked.
mouseEvent: MouseEvent	The native mouse event.

ChartContextMenuArgs

date: Date	Date at the click position.
area: 'header' \| 'content'	Whether the click was on the header or the content area.
task: Task \| null	Task at the click position, or null.
mouseEvent: MouseEvent	The native mouse event.

TasksPastedEventArgs

tasks: Task[]	The pasted tasks.
links: TaskLink[]	The pasted links.
taskIdMap: Map<string, Task>	Maps original task ID → pasted task.
droppedLinks: DroppedLinkInfo[]	Links that could not be recreated.

DroppedLinkInfo

type: TaskLinkType	Original link type.
fromId: string	Original predecessor task ID.
toId: string	Original successor task ID.
externalSide: 'from' \| 'to'	Which end is outside the pasted set.

Export options

GanttCsvExportOptions

delimiter?: ',' \| ';' \| '\t'	Column delimiter. Default: ','.
includeHeaders?: boolean	Include column headers. Default: true.
columns?: string[]	Which columns to export (by code). Default: all visible.
includeLinks?: boolean	Append dependency links as a separate section. Default: false.

GanttPdfExportOptions

pageSize?: 'A4' \| 'A3' \| 'Letter' \| 'Legal'	Page format. Default: 'A4'.
orientation?: 'portrait' \| 'landscape'	Page orientation. Default: 'landscape'.
margin?: { top, right, bottom, left }	Page margins in mm. Default: 10mm on all sides.
header?: string \| ((page, total) => string)	Header text on each page.
footer?: string \| ((page, total) => string)	Footer text on each page.
includeSheet?: boolean	Include the sheet (left panel). Default: true.
includeChart?: boolean	Include the chart (timeline). Default: true.
quality?: number	Image quality (0–1). Default: 1.
fitToSinglePage?: boolean	Export as a single page. Default: false.

GanttExcelExportOptions

sheetName?: string	Name of the tasks sheet. Default: 'Tasks'.
includeLinksSheet?: boolean	Include a sheet with dependency links. Default: true.
includeResourcesSheet?: boolean	Include a sheet with resources. Default: true.
includeFormatting?: boolean	Apply cell formatting (bold summaries, column widths). Default: true.
columns?: string[]	Which columns to export (by code). Default: all visible.

TaskFilters

Built-in filter predicates. Each is a TaskFilterFn or a factory that returns one.

criticalPath	Tasks on the critical path.
incomplete	Tasks with progress below 100%.
complete	Tasks with 100% progress.
behindSchedule	Tasks past their end date with incomplete progress.
milestones	Milestone tasks only.
byResource(resource: Resource)	Tasks assigned to a specific resource.
byDateRange(start: Date, end: Date)	Tasks overlapping a date range.
byName(search: string)	Tasks whose name contains the search string (case-insensitive).
combine(...filters: TaskFilterFn[])	Combines multiple filters with AND logic.

Enums

TaskType

'task'	A regular schedulable task with start, end, and duration.
'milestone'	A zero-duration event marking a key date.
'summary'	A parent task whose dates and progress are computed from subtasks.
'empty'	An empty row placeholder.

TaskLinkType

'finishToStart'	Successor starts after predecessor finishes (most common).
'startToStart'	Both tasks start at the same time.
'finishToFinish'	Both tasks finish at the same time.
'startToFinish'	Successor finishes when predecessor starts.

ConstraintType

'asap'	As Soon As Possible (default).
'alap'	As Late As Possible.
'mso'	Must Start On — task must start on the constraint date.
'mfo'	Must Finish On — task must finish on the constraint date.
'snet'	Start No Earlier Than — task cannot start before the constraint date.
'snlt'	Start No Later Than — task cannot start after the constraint date.
'fnet'	Finish No Earlier Than — task cannot finish before the constraint date.
'fnlt'	Finish No Later Than — task cannot finish after the constraint date.

LengthUnit

'minute'	Duration in minutes.
'hour'	Duration in hours.
'day'	Duration in working days (default).
'week'	Duration in weeks.
'month'	Duration in months.

WorkUnit

'minute'	Work effort in minutes.
'hour'	Work effort in hours.
'day'	Work effort in days.

DayOfWeek

Day of the week.

ResourceType

'unique'	A unique resource (e.g. a specific person).
'generic'	A generic resource (e.g. 'Developer' role).

RateType

'perDay'	Cost rate per working day.
'perHour'	Cost rate per working hour.

ConnectorSide

'start' | 'finish'

Which end of a task a link connects to.

ColorValue

number | ColorDefinition

A theme color index (number) or a custom color definition.

TaskFilterFn

(task: Task) => boolean

Predicate function used to filter tasks.

TaskLabelPosition

'none'	No label.
'inside'	Label inside the task bar.
'right'	Label to the right of the task bar.
'insideOrRight'	Inside if it fits, otherwise to the right.

TaskLabelContent

'name'	Display task name.
'resource'	Display assigned resource names.
'progress'	Display progress percentage.
'nameAndProgress'	Display name and progress.
'nameAndResource'	Display name and resource names.

SummaryMarkType

'full'	Full triangle marks at both ends.
'half'	Half-height marks at both ends.

CurrencySymbolDisplayMode

'beforeAmount'	Symbol directly before amount ($100).
'afterAmount'	Symbol directly after amount (100$).
'beforeAmountWithSpace'	Symbol before amount with space ($ 100).
'afterAmountWithSpace'	Symbol after amount with space (100 $).

Utility functions

getLinkType(from: ConnectorSide, to: ConnectorSide): TaskLinkType

Determine the link type from which sides of the tasks are connected.