Grouping APIs

State#

Grouping state is stored on the table using the following shape:

export type GroupingState = string[]

export type GroupingTableState = {
  grouping: GroupingState
}

Aggregation Functions#

The following aggregation functions are built-in to the table core:

• sum
  • Sums the values of a group of rows
• min
  • Finds the minimum value of a group of rows
• max
  • Finds the maximum value of a group of rows
• extent
  • Finds the minimum and maximum values of a group of rows
• mean
  • Finds the mean/average value of a group of rows
• median
  • Finds the median value of a group of rows
• unique
  • Finds the unique values of a group of rows
• uniqueCount
  • Finds the number of unique values of a group of rows
• count
  • Calculates the number of rows in a group

Every grouping function receives:

• A function to retrieve the leaf values of the groups rows
• A function to retrieve the immediate-child values of the groups rows

and should return a value (usually primitive) to build the aggregated row model.

This is the type signature for every aggregation function:

export type AggregationFn<TData extends AnyData> = (
  getLeafRows: () => Row<TData>[],
  getChildRows: () => Row<TData>[]
) => any

Using Aggregation Functions#

Aggregation functions can be used/referenced/defined by passing the following to columnDefinition.aggregationFn:

• A string that references a built-in aggregation function
• A string that references a custom aggregation functions provided via the tableOptions.aggregationFns option
• A function directly provided to the columnDefinition.aggregationFn option

The final list of aggregation functions available for the columnDef.aggregationFn use the following type:

export type AggregationFnOption<TData extends AnyData> =
  | 'auto'
  | keyof AggregationFns
  | BuiltInAggregationFn
  | AggregationFn<TData>

Column Def Options#

aggregationFn#

aggregationFn?: AggregationFn | keyof AggregationFns | keyof BuiltInAggregationFns

The aggregation function to use with this column.

Options:

• A string referencing a built-in aggregation function)
• A custom aggregation function

aggregatedCell#

aggregatedCell?: Renderable<
  {
    table: Table<TData>
    row: Row<TData>
    column: Column<TData>
    cell: Cell<TData>
    getValue: () => any
    renderValue: () => any
  }
>

The cell to display each row for the column if the cell is an aggregate. If a function is passed, it will be passed a props object with the context of the cell and should return the property type for your adapter (the exact type depends on the adapter being used).

enableGrouping#

enableGrouping?: boolean

Enables/disables grouping for this column.

getGroupingValue#

getGroupingValue?: (row: TData) => any

Specify a value to be used for grouping rows on this column. If this option is not specified, the value derived from accessorKey / accessorFn will be used instead.

Column API#

aggregationFn#

aggregationFn?: AggregationFnOption<TData>

The resolved aggregation function for the column.

getCanGroup#

getCanGroup: () => boolean

Returns whether or not the column can be grouped.

getIsGrouped#

getIsGrouped: () => boolean

Returns whether or not the column is currently grouped.

getGroupedIndex#

getGroupedIndex: () => number

Returns the index of the column in the grouping state.

toggleGrouping#

toggleGrouping: () => void

Toggles the grouping state of the column.

getToggleGroupingHandler#

getToggleGroupingHandler: () => () => void

Returns a function that toggles the grouping state of the column. This is useful for passing to the onClick prop of a button.

getAutoAggregationFn#

getAutoAggregationFn: () => AggregationFn<TData> | undefined

Returns the automatically inferred aggregation function for the column.

getAggregationFn#

getAggregationFn: () => AggregationFn<TData> | undefined

Returns the aggregation function for the column.

Row API#

groupingColumnId#

groupingColumnId?: string

If this row is grouped, this is the id of the column that this row is grouped by.

groupingValue#

groupingValue?: any

If this row is grouped, this is the unique/shared value for the groupingColumnId for all of the rows in this group.

getIsGrouped#

getIsGrouped: () => boolean

Returns whether or not the row is currently grouped.

getGroupingValue#

getGroupingValue: (columnId: string) => unknown

Returns the grouping value for any row and column (including leaf rows).

Table Options#

aggregationFns#

aggregationFns?: Record<string, AggregationFn>

This option allows you to define custom aggregation functions that can be referenced in a column's aggregationFn option by their key. Example:

declare module '@tanstack/table-core' {
  interface AggregationFns {
    myCustomAggregation: AggregationFn<unknown>
  }
}

const column = columnHelper.data('key', {
  aggregationFn: 'myCustomAggregation',
})

const table = useReactTable({
  columns: [column],
  aggregationFns: {
    myCustomAggregation: (columnId, leafRows, childRows) => {
      // return the aggregated value
    },
  },
})

manualGrouping#

manualGrouping?: boolean

Enables manual grouping. If this option is set to true, the table will not automatically group rows using getGroupedRowModel() and instead will expect you to manually group the rows before passing them to the table. This is useful if you are doing server-side grouping and aggregation.

onGroupingChange#

onGroupingChange?: OnChangeFn<GroupingState>

If this function is provided, it will be called when the grouping state changes and you will be expected to manage the state yourself. You can pass the managed state back to the table via the tableOptions.state.grouping option.

enableGrouping#

enableGrouping?: boolean

Enables/disables grouping for all columns.

getGroupedRowModel#

getGroupedRowModel?: (table: Table<TData>) => () => RowModel<TData>

Returns the row model after grouping has taken place, but no further.

groupedColumnMode#

groupedColumnMode?: false | 'reorder' | 'remove' // default: `reorder`

Grouping columns are automatically reordered by default to the start of the columns list. If you would rather remove them or leave them as-is, set the appropriate mode here.

Table API#

setGrouping#

setGrouping: (updater: Updater<GroupingState>) => void

Sets or updates the state.grouping state.

resetGrouping#

resetGrouping: (defaultState?: boolean) => void

Resets the grouping state to initialState.grouping, or true can be passed to force a default blank state reset to [].

getPreGroupedRowModel#

getPreGroupedRowModel: () => RowModel<TData>

Returns the row model for the table before any grouping has been applied.

getGroupedRowModel#

getGroupedRowModel: () => RowModel<TData>

Returns the row model for the table after grouping has been applied.

Cell API#

getIsAggregated#

getIsAggregated: () => boolean

Returns whether or not the cell is currently aggregated.

getIsGrouped#

getIsGrouped: () => boolean

Returns whether or not the cell is currently grouped.

getIsPlaceholder#

getIsPlaceholder: () => boolean

Returns whether or not the cell is currently a placeholder.