Grouping

State

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

tsx
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:

tsx
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:

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

Column Def Options

aggregationFn

tsx
aggregationFn?: AggregationFn | keyof AggregationFns | keyof BuiltInAggregationFns

The aggregation function to use with this column.

Options:

aggregatedCell

tsx
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

tsx
enableGrouping?: boolean

Enables/disables grouping for this column.

Column API

aggregationFn

tsx
aggregationFn?: AggregationFnOption<TData>

The resolved aggregation function for the column.

getCanGroup

tsx
getCanGroup: () => boolean

Returns whether or not the column can be grouped.

getIsGrouped

tsx
getIsGrouped: () => boolean

Returns whether or not the column is currently grouped.

getGroupedIndex

tsx
getGroupedIndex: () => number

Returns the index of the column in the grouping state.

toggleGrouping

tsx
toggleGrouping: () => void

Toggles the grouping state of the column.

getToggleGroupingHandler

tsx
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

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

Returns the automatically inferred aggregation function for the column.

getAggregationFn

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

Row API

groupingColumnId

tsx
groupingColumnId?: string

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

groupingValue

tsx
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

tsx
getIsGrouped: () => boolean

Returns whether or not the row is currently grouped.

Table Options

aggregationFns

tsx
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:

tsx
declare module '@tanstack/table-core' {
interface AggregationFns {
myCustomAggregation: AggregationFn<unknown>
}
}
const column = columnHelper.data('key', {
aggregationFn: 'myCustomAggregation',
})
const table = useTable({
columns: [column],
aggregationFns: {
myCustomAggregation: (columnId, leafRows, childRows) => {
// return the aggregated value
},
},
})

manualGrouping

tsx
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

tsx
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

tsx
enableGrouping?: boolean

Enables/disables grouping for all columns.

getGroupedRowModel

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

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

groupedColumnMode

tsx
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 API

setGrouping

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

Sets or updates the state.grouping state.

resetGrouping

tsx
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

tsx
getPreGroupedRowModel: () => RowModel<TData>

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

getGroupedRowModel

tsx
getGroupedRowModel: () => RowModel<TData>

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