JavaScript Data GridColumn Definitions
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Each column in the grid is defined using a Column Definition (ColDef). Columns are positioned in the grid according to the order the Column Definitions are specified in the Grid Options.

The following example shows a simple grid with 3 columns defined:

const gridOptions = {
    // define 3 columns
    columnDefs: [
        { field: 'athlete' },
        { field: 'sport' },
        { field: 'age' },

    // other grid options ...

See Column Properties for a list of all properties that can be applied to a column.

If you want the columns to be grouped, you can include them as children like so:

// put the three columns into a group
columnDefs: [
        headerName: 'Group A',
        children: [
            { field: 'athlete' },
            { field: 'sport' },
            { field: 'age' }

Groups are explained in more detail in the section Column Groups.

Accessing Row Data Values

The colDef.field property is used to access values from the row data object. In most cases the field will be a property name from the row data object. If, however, the row data contains nested objects, you can use dot notation to reference deep property values.

For example, if the row data has an object property medals that contains the individual medal counts, then to display gold medals won use the field value ''.

const gridOptions = {
    rowData: [
            athlete: 'Michael Phelps',
            medals: {
                gold: 8, silver: 1, bronze: 0
    columnDefs: [
        { field: 'athlete' },
        // Using dot notation to access nested property
        { field: '', headerName: 'Gold' },

    // other grid options ...

For alternative ways to provide cell data, such as value getters, see the documentation on Value Getters.

Suppress Field Dot Notation

If your row data objects have dots in their property names, that should not be treated as deep references, then set the grid property suppressFieldDotNotation to true. This prevents the dots being interpreted as deep references across all column definitions.

Custom Column Types

In addition to the above, the grid provides additional ways to help simplify and avoid duplication of column definitions. This is done through the following:

  • defaultColDef: contains properties that all columns will inherit.
  • defaultColGroupDef: contains properties that all column groups will inherit.
  • columnTypes: contains a set of properties that can be reused by referencing them in the type property of a column definition.

Default columns can specify any of the column properties available on a column. Column types can specify any of the column properties except type.

Column Types are designed to work on Columns only, i.e. they won't be applied to Column Groups.

The following code snippet demonstrates these three properties:

const gridOptions = {
    columnDefs: [
        // uses the default column properties
        { headerName: 'Col A', field: 'a'},
        // overrides the default with a number filter
        { headerName: 'Col B', field: 'b', filter: 'agNumberColumnFilter' },
        // overrides the default using a column type
        { headerName: 'Col C', field: 'c', type: 'nonEditableColumn' },
        // overrides the default using a multiple column types
        { headerName: 'Col D', field: 'd', type: ['dateColumn', 'nonEditableColumn'] }

    // a default column definition with properties that get applied to every column
    defaultColDef: {
        // set every column width
        width: 100,
        // make every column editable
        editable: true,
        // make every column use 'text' filter by default
        filter: 'agTextColumnFilter',

    // a default column group definition with properties that get applied to every column group 
    defaultColGroupDef: {
      marryChildren: true,

    // define a column type (you can define as many as you like)
    columnTypes: {
        nonEditableColumn: { editable: false },
        dateColumn: {
            filter: 'agDateColumnFilter',
            filterParams: { comparator: myDateComparator },
            suppressMenu: true

    // other grid options ...

When the grid creates a column it starts with the default column definition, then adds properties defined on the Cell Data Type if enabled, then adds properties defined via column types, and then finally adds in properties from the specific column definition.

At each stage if a column property already exists, the latter will override the existing value. For example, if the defaultColDef sets editable: true but a columnType sets editable: false then this column will not be editable.

For example, the following is an outline of the steps used when creating 'Col C' shown above:

// Step 1: the grid starts with an empty definition

// Step 2: default column properties are merged in
{ width: 100, editable: true, filter: 'agTextColumnFilter' }

// Step 3: column type properties are merged in (using the 'type' property), overriding where necessary
{ width: 100, editable: false, filter: 'agTextColumnFilter' }

// Step 4: finally column definition properties are merged in, overriding where necessary
{ headerName: 'Col C', field: 'c', width: 100, editable: false, filter: 'agTextColumnFilter' }

The following example demonstrates the different configuration properties in action.

Right Aligned and Numeric Columns

The grid provides a handy shortcut for aligning columns to the right. Setting the column definition type to rightAligned aligns the column header and contents to the right, which makes the scanning of the data easier for the user.

Because right alignment is used for numbers, we also provided an alias numericColumn that can be used to align the header and cell text to the right.

const gridOptions = {
    columnDefs: [
        { headerName: 'Column A', field: 'a' },
        { headerName: 'Column B', field: 'b', type: 'rightAligned' },
        { headerName: 'Column C', field: 'c', type: 'numericColumn' },

    // other grid options ...

The rightAligned column type works by setting the header and cell class properties as follows. If you manually set either headerClass or cellClass then you may need to include the right aligned CSS classes yourself as column type properties are overridden by explicitly defined column properties.

rightAligned: {
    headerClass: 'ag-right-aligned-header',
    cellClass: 'ag-right-aligned-cell'

Column IDs

Each column generated by the grid is given a unique Column ID, which is used in parts of the Grid API.

If you are using the API and the column IDs are a little complex (e.g. if two columns have the same field, or if you are using valueGetter instead of field) then it is useful to understand how column IDs are generated.

If the user provides colId in the column definition, then this is used, otherwise the field is used. If both colId and field exist then colId gets preference. If neither colId nor field exists then a number is assigned. Finally, the ID is ensured to be unique by appending '_n' if necessary, where n is the first positive number that allows uniqueness.

In the example below, columns are set up to demonstrate the different ways IDs are generated. Open the example in a new tab and observe the output in the dev console. Note the following:

  • Col 1 and Col 2 both use colId. The grid appends '_1' to Col 2 to make the ID unique.
  • Col 3 and Col 4 both use field. The grid appends '_1' to Col 4 to make the ID unique.
  • Col 5 and Col 6 have neither colId or field so the grid generates column IDs.