---
title: Grid
description: Grid
element: vaadin-grid
---

## Description

`<vaadin-grid>` is a free, high quality data grid / data table Web Component. The content of the
the grid can be populated by using renderer callback function.

### Quick Start

Start with an assigning an array to the [`items`](/elements/vaadin-grid#items) property to visualize your data.

Use the [`<vaadin-grid-column>`](/elements/vaadin-grid-column) element to configure the grid columns. Set `path` and `header`
shorthand properties for the columns to define what gets rendered in the cells of the column.

#### Example:
```html
<vaadin-grid>
  <vaadin-grid-column path="name.first" header="First name"></vaadin-grid-column>
  <vaadin-grid-column path="name.last" header="Last name"></vaadin-grid-column>
  <vaadin-grid-column path="email"></vaadin-grid-column>
</vaadin-grid>
```

For custom content `vaadin-grid-column` element provides you with three types of `renderer` callback functions: `headerRenderer`,
`renderer` and `footerRenderer`.

Each of those renderer functions provides `root`, `column`, `model` arguments when applicable.
Generate DOM content, append it to the `root` element and control the state
of the host element by accessing `column`. Before generating new content,
users are able to check if there is already content in `root` for reusing it.

Renderers are called on initialization of new column cells and each time the
related row model is updated. DOM generated during the renderer call can be reused
in the next renderer call and will be provided with the `root` argument.
On first call it will be empty.

#### Example:
```html
<vaadin-grid>
  <vaadin-grid-column></vaadin-grid-column>
  <vaadin-grid-column></vaadin-grid-column>
  <vaadin-grid-column></vaadin-grid-column>
</vaadin-grid>
```
```js
const grid = document.querySelector('vaadin-grid');
grid.items = [{'name': 'John', 'surname': 'Lennon', 'role': 'singer'},
              {'name': 'Ringo', 'surname': 'Starr', 'role': 'drums'}];

const columns = grid.querySelectorAll('vaadin-grid-column');

columns[0].headerRenderer = function(root) {
  root.textContent = 'Name';
};
columns[0].renderer = function(root, column, model) {
  root.textContent = model.item.name;
};

columns[1].headerRenderer = function(root) {
  root.textContent = 'Surname';
};
columns[1].renderer = function(root, column, model) {
  root.textContent = model.item.surname;
};

columns[2].headerRenderer = function(root) {
  root.textContent = 'Role';
};
columns[2].renderer = function(root, column, model) {
  root.textContent = model.item.role;
};
```

The following properties are available in the `model` argument:

Property name | Type | Description
--------------|------|------------
`index`| Number | The index of the item.
`item` | String or Object | The item.
`level` | Number | Number of the item's tree sublevel, starts from 0.
`expanded` | Boolean | True if the item's tree sublevel is expanded.
`selected` | Boolean | True if the item is selected.
`detailsOpened` | Boolean | True if the item's row details are open.
`hasChildren` | Boolean | True if the item has children

The following helper elements can be used for further customization:
- [`<vaadin-grid-column-group>`](/elements/vaadin-grid-column-group)
- [`<vaadin-grid-filter>`](/elements/vaadin-grid-filter)
- [`<vaadin-grid-sorter>`](/elements/vaadin-grid-sorter)
- [`<vaadin-grid-selection-column>`](/elements/vaadin-grid-selection-column)
- [`<vaadin-grid-tree-toggle>`](/elements/vaadin-grid-tree-toggle)

__Note that the helper elements must be explicitly imported.__
If you want to import everything at once you can use the `all-imports.js` entrypoint.

### Lazy Loading with Function Data Provider

In addition to assigning an array to the items property, you can alternatively
provide the `<vaadin-grid>` data through the
[`dataProvider`](/elements/vaadin-grid#dataprovider) function property.
The `<vaadin-grid>` calls this function lazily, only when it needs more data
to be displayed.

See the [`dataProvider`](/elements/vaadin-grid#dataprovider) property
documentation for the detailed data provider arguments description.

__Note that expanding the tree grid's item will trigger a call to the `dataProvider`.__

__Also, note that when using function data providers, the total number of items
needs to be set manually. The total number of items can be returned
in the second argument of the data provider callback:__

```javascript
grid.dataProvider = ({page, pageSize}, callback) => {
  // page: the requested page index
  // pageSize: number of items on one page
  const url = `https://api.example/data?page=${page}&per_page=${pageSize}`;

  fetch(url)
    .then((res) => res.json())
    .then(({ employees, totalSize }) => {
      callback(employees, totalSize);
    });
};
```

__Alternatively, you can use the `size` property to set the total number of items:__

```javascript
grid.size = 200; // The total number of items
grid.dataProvider = ({page, pageSize}, callback) => {
  const url = `https://api.example/data?page=${page}&per_page=${pageSize}`;

  fetch(url)
    .then((res) => res.json())
    .then((resJson) => callback(resJson.employees));
};
```

### Styling

The following shadow DOM parts are available for styling:

Part name                  | Description
---------------------------|----------------
`row`                      | Row in the internal table
`body-row`                 | Body row in the internal table
`header-row`               | Header row in the internal table
`footer-row`               | Footer row in the internal table
`collapsed-row`            | Collapsed row
`expanded-row`             | Expanded row
`selected-row`             | Selected row
`nonselectable-row`        | Row that the user may not select or deselect
`details-opened-row`       | Row with details open
`odd-row`                  | Odd row
`even-row`                 | Even row
`first-row`                | The first body row
`first-header-row`         | The first header row
`first-footer-row`         | The first footer row
`last-row`                 | The last body row
`last-header-row`          | The last header row
`last-footer-row`          | The last footer row
`dragstart-row`            | Set on the row for one frame when drag is starting.
`dragover-above-row`       | Set on the row when the a row is dragged over above
`dragover-below-row`       | Set on the row when the a row is dragged over below
`dragover-on-top-row`      | Set on the row when the a row is dragged over on top
`drag-disabled-row`        | Set to a row that isn't available for dragging
`drop-disabled-row`        | Set to a row that can't be dropped on top of
`cell`                     | Cell in the internal table
`header-cell`              | Header cell in the internal table
`body-cell`                | Body cell in the internal table
`footer-cell`              | Footer cell in the internal table
`details-cell`             | Row details cell in the internal table
`focused-cell`             | Focused cell in the internal table
`odd-row-cell`             | Cell in an odd row
`even-row-cell`            | Cell in an even row
`first-row-cell`           | Cell in the first body row
`last-row-cell`            | Cell in the last body row
`first-header-row-cell`    | Cell in the first header row
`first-footer-row-cell`    | Cell in the first footer row
`last-header-row-cell`     | Cell in the last header row
`last-footer-row-cell`     | Cell in the last footer row
`loading-row-cell`         | Cell in a row that is waiting for data from data provider
`selected-row-cell`        | Cell in a selected row
`nonselectable-row-cell`   | Cell in a row that the user may not select or deselect
`collapsed-row-cell`       | Cell in a collapsed row
`expanded-row-cell`        | Cell in an expanded row
`details-opened-row-cell`  | Cell in an row with details open
`dragstart-row-cell`       | Cell in the ghost image row, but not in a source row
`drag-source-row-cell`     | Cell in a source row, but not in the ghost image
`dragover-above-row-cell`  | Cell in a row that has another row dragged over above
`dragover-below-row-cell`  | Cell in a row that has another row dragged over below
`dragover-on-top-row-cell` | Cell in a row that has another row dragged over on top
`drag-disabled-row-cell`   | Cell in a row that isn't available for dragging
`drop-disabled-row-cell`   | Cell in a row that can't be dropped on top of
`frozen-cell`              | Frozen cell in the internal table
`frozen-to-end-cell`       | Frozen to end cell in the internal table
`last-frozen-cell`         | Last frozen cell
`first-frozen-to-end-cell` | First cell frozen to end
`first-column-cell`        | First visible cell on a row
`last-column-cell`         | Last visible cell on a row
`reorder-allowed-cell`     | Cell in a column where another column can be reordered
`reorder-dragging-cell`    | Cell in a column currently being reordered
`resize-handle`            | Handle for resizing the columns
`empty-state`              | The container for the content to be displayed when there are no body rows to show
`reorder-ghost`            | Ghost element of the header cell being dragged

The following state attributes are available for styling:

Attribute             | Description                                                                                       | Part name
----------------------|---------------------------------------------------------------------------------------------------|-----------
`loading`             | Set when the grid is loading data from data provider                                              | :host
`interacting`         | Keyboard navigation in interaction mode                                                           | :host
`navigating`          | Keyboard navigation in navigation mode                                                            | :host
`overflow`            | Set when rows are overflowing the grid viewport. Possible values: `top`, `bottom`, `start`, `end` | :host
`reordering`          | Set when the grid's columns are being reordered                                                   | :host
`dragover`            | Set when the grid (not a specific row) is dragged over                                            | :host
`dragging-rows`       | Set when grid rows are dragged                                                                    | :host
`reorder-status`      | Reflects the status of a cell while columns are being reordered                                   | cell
`frozen`              | Frozen cell                                                                                       | cell
`frozen-to-end`       | Cell frozen to end                                                                                | cell
`last-frozen`         | Last frozen cell                                                                                  | cell
`first-frozen-to-end` | First cell frozen to end                                                                          | cell
`first-column`        | First visible cell on a row                                                                       | cell
`last-column`         | Last visible cell on a row                                                                        | cell
`selected`            | Selected row                                                                                      | row
`expanded`            | Expanded row                                                                                      | row
`details-opened`      | Row with details open                                                                             | row
`loading`             | Row that is waiting for data from data provider                                                   | row
`odd`                 | Odd row                                                                                           | row
`first`               | The first body row                                                                                | row
`last`                | The last body row                                                                                 | row
`dragstart`           | Set for one frame when starting to drag a row. The value is a number when dragging multiple rows  | row
`dragover`            | Set when the row is dragged over                                                                  | row
`drag-disabled`       | Set to a row that isn't available for dragging                                                    | row
`drop-disabled`       | Set to a row that can't be dropped on top of                                                      | row

See [Styling Components](https://vaadin.com/docs/latest/styling/styling-components) documentation.

## Properties

### accessibleName

**Type:** `string`

String used to label the grid to screen reader users.

### activeItem

**Type:** `any`

The item user has last interacted with. Turns to `null` after user deactivates
the item by re-interacting with the currently active item.

### allRowsVisible

**Type:** `boolean`

If true, the grid's height is defined by its rows.

Effectively, this disables the grid's virtual scrolling so that all the rows are rendered in the DOM at once.
If the grid has a large number of items, using the feature is discouraged to avoid performance issues.

### cellPartNameGenerator

**Type:** `GridCellPartNameGenerator<any> | null | undefined`

A function that allows generating CSS `part` names for grid cells in Shadow DOM based
on their row and column, for styling from outside using the `::part()` selector.

The return value should be the generated part name as a string, or multiple part names
separated by whitespace characters.

Receives two arguments:
- `column` The `<vaadin-grid-column>` element (`undefined` for details-cell).
- `model` The object with the properties related with
  the rendered item, contains:
  - `model.index` The index of the item.
  - `model.item` The item.
  - `model.expanded` Sublevel toggle state.
  - `model.level` Level of the tree represented with a horizontal offset of the toggle button.
  - `model.selected` Selected state.

See also: [GridCellPartNameGenerator](#gridcellpartnamegenerator)

### columnRendering

**Type:** `ColumnRendering`

Allows you to choose between modes for rendering columns in the grid:

"eager" (default): All columns are rendered upfront, regardless of their visibility within the viewport.
This mode should generally be preferred, as it avoids the limitations imposed by the "lazy" mode.
Use this mode unless the grid has a large number of columns and performance outweighs the limitations
in priority.

"lazy": Optimizes the rendering of cells when there are multiple columns in the grid by virtualizing
horizontal scrolling. In this mode, body cells are rendered only when their corresponding columns are
inside the visible viewport.

Using "lazy" rendering should be used only if you're dealing with a large number of columns and performance
is your highest priority. For most use cases, the default "eager" mode is recommended due to the
limitations imposed by the "lazy" mode.

When using the "lazy" mode, keep the following limitations in mind:

- Row Height: When only a number of columns are visible at once, the height of a row can only be that of
the highest cell currently visible on that row. Make sure each cell on a single row has the same height
as all other cells on that row. If row cells have different heights, users may experience jumpiness when
scrolling the grid horizontally as lazily rendered cells with different heights are scrolled into view.

- Auto-width Columns: For the columns that are initially outside the visible viewport but still use auto-width,
only the header content is taken into account when calculating the column width because the body cells
of the columns outside the viewport are not initially rendered.

- Screen Reader Compatibility: Screen readers may not be able to associate the focused cells with the correct
headers when only a subset of the body cells on a row is rendered.

- Keyboard Navigation: Tabbing through focusable elements inside the grid body may not work as expected because
some of the columns that would include focusable elements in the body cells may be outside the visible viewport
and thus not rendered.

See also: [ColumnRendering](#columnrendering)

### columnReorderingAllowed

**Type:** `boolean`

Set to true to allow column reordering.

### dataProvider

**Type:** `GridDataProvider<any> | null | undefined`

Function that provides items lazily. Receives arguments `params`, `callback`

`params.page` Requested page index

`params.pageSize` Current page size

`params.filters` Currently applied filters

`params.sortOrders` Currently applied sorting orders

`params.parentItem` When tree is used, and sublevel items
are requested, reference to parent item of the requested sublevel.
Otherwise `undefined`.

`callback(items, size)` Callback function with arguments:
  - `items` Current page of items
  - `size` Total number of items. When tree sublevel items
    are requested, total number of items in the requested sublevel.
    Optional when tree is not used, required for tree.

See also: [GridDataProvider](#griddataprovider)

### detailsOpenedItems

**Type:** `any[]`

An array containing references to items with open row details.

### dragFilter

**Type:** `GridDragAndDropFilter<any> | null | undefined`

A function that filters dragging of specific grid rows. The return value should be false
if dragging of the row should be disabled.

Receives one argument:
- `model` The object with the properties related with
  the rendered item, contains:
  - `model.index` The index of the item.
  - `model.item` The item.
  - `model.expanded` Sublevel toggle state.
  - `model.level` Level of the tree represented with a horizontal offset of the toggle button.
  - `model.selected` Selected state.

See also: [GridDragAndDropFilter](#griddraganddropfilter)

### dropFilter

**Type:** `GridDragAndDropFilter<any> | null | undefined`

A function that filters dropping on specific grid rows. The return value should be false
if dropping on the row should be disabled.

Receives one argument:
- `model` The object with the properties related with
  the rendered item, contains:
  - `model.index` The index of the item.
  - `model.item` The item.
  - `model.expanded` Sublevel toggle state.
  - `model.level` Level of the tree represented with a horizontal offset of the toggle button.
  - `model.selected` Selected state.

See also: [GridDragAndDropFilter](#griddraganddropfilter)

### dropMode

**Type:** `GridDropMode | null | undefined`

Defines the locations within the Grid row where an element can be dropped.

Possible values are:
- `between`: The drop event can happen between Grid rows.
- `on-top`: The drop event can happen on top of Grid rows.
- `on-top-or-between`: The drop event can happen either on top of or between Grid rows.
- `on-grid`: The drop event will not happen on any specific row, it will show the drop target outline around the whole grid.

See also: [GridDropMode](#griddropmode)

### expandedItems

**Type:** `any[]`

An array that contains the expanded items.

### isItemSelectable

**Type:** `(item: any) => boolean`

A function to check whether a specific item in the grid may be
selected or deselected by the user. Used by the selection column to
conditionally enable to disable checkboxes for individual items. This
function does not prevent programmatic selection/deselection of
items. Changing the function does not modify the currently selected
items.

Configuring this function hides the select all checkbox of the grid
selection column, which means users can not select or deselect all
items anymore, nor do they get feedback on whether all items are
selected or not.

Receives an item instance and should return a boolean indicating
whether users may change the selection state of that item.

### itemHasChildrenPath

**Type:** `string`

Path to an item sub-property that indicates whether the item has child items.

### itemIdPath

**Type:** `string | null | undefined`

Path to an item sub-property that identifies the item.

### items

**Type:** `any[] | null | undefined`

An array containing the items which will be passed to renderer functions.

### loading

**Type:** `boolean | null | undefined`

`true` while data is being requested from the data provider.

### multiSort

**Type:** `boolean`

When `true`, all `<vaadin-grid-sorter>` are applied for sorting.

### multiSortOnShiftClick

**Type:** `boolean`

When `true`, Shift-clicking an unsorted column's sorter adds it to the multi-sort.
Shift + Space does the same action via keyboard. This property has precedence over the
`multiSort` property. If `multiSortOnShiftClick` is true, the multiSort property is effectively ignored.

### multiSortPriority

**Type:** `"append" | "prepend"`

Controls how columns are added to the sort order when using multi-sort.
The sort order is visually indicated by numbers in grid sorters placed in column headers.

By default, whenever an unsorted column is sorted, or the sort-direction of a column is
changed, that column gets sort priority 1, thus affecting the priority for all the other
sorted columns. This is identical to using `multi-sort-priority="prepend"`.

Using this property allows to change this behavior so that sorting an unsorted column
would add it to the "end" of the sort, and changing column's sort direction would retain
it's previous priority. To set this, use `multi-sort-priority="append"`.

### pageSize

**Type:** `number`

Number of items fetched at a time from the dataprovider.

### rowDetailsRenderer

**Type:** `GridRowDetailsRenderer<any> | null | undefined`

Custom function for rendering the content of the row details.
Receives three arguments:

- `root` The row details content DOM element. Append your content to it.
- `grid` The `<vaadin-grid>` element.
- `model` The object with the properties related with
  the rendered item, contains:
  - `model.index` The index of the item.
  - `model.item` The item.
  - `model.level` The number of the item's tree sublevel, starts from 0.
  - `model.expanded` True if the item's tree sublevel is expanded.
  - `model.selected` True if the item is selected.

See also: [GridRowDetailsRenderer](#gridrowdetailsrenderer)

### rowsDraggable

**Type:** `boolean | null | undefined`

Marks the grid's rows to be available for dragging.

### selectedItems

**Type:** `any[]`

An array that contains the selected items.

### size

**Type:** `number`

The number of root-level items in the grid.

## Methods

### clearCache

**Type:** `() => void`

Clears the cached pages and reloads data from dataprovider when needed.

### closeItemDetails

**Type:** `(item: any) => void`

Close the details row of a given item.

### collapseItem

**Type:** `(item: any) => void`

Collapses the given item tree.

### deselectItem

**Type:** `(item: any) => void`

Deselects the given item if it is already selected.

### expandItem

**Type:** `(item: any) => void`

Expands the given item tree.

### filterDragAndDrop

**Type:** `() => void`

Runs the `dragFilter` and `dropFilter` hooks for the visible cells.
If the filter depends on varying conditions, you may need to
call this function manually in order to update the draggability when
the conditions change.

### generateCellPartNames

**Type:** `() => void`

Runs the `cellPartNameGenerator` for the visible cells.
If the generator depends on varying conditions, you need to
call this function manually in order to update the styles when
the conditions change.

### getEventContext

**Type:** `(event: Event) => GridEventContext<any>`

Returns an object with context information about the event target:
- `item`: the data object corresponding to the targeted row (not specified when targeting header or footer)
- `column`: the column element corresponding to the targeted cell (not specified when targeting row details)
- `section`: whether the event targeted the body, header, footer or details of the grid

These additional properties are included when `item` is specified:
- `index`: the index of the item
- `selected`: the selected state of the item
- `detailsOpened`: whether the row details are open for the item
- `expanded`: the expanded state of the tree toggle
- `level`: the tree hierarchy level
- `hasChildren`: whether the item has children

The returned object is populated only when a grid cell, header, footer or row details is found in `event.composedPath()`.
This means mostly mouse and keyboard events. If such a grid part is not found in the path, an empty object is returned.
This may be the case eg. if the event is fired on the `<vaadin-grid>` element and not any deeper in the DOM, or if
the event targets the empty part of the grid body.

### getItemId

**Type:** `(item: any) => unknown`

Returns a value that identifies the item. Uses `itemIdPath` if available.
Can be customized by overriding.

### openItemDetails

**Type:** `(item: any) => void`

Open the details row of a given item.

### requestContentUpdate

**Type:** `() => void`

Requests an update for the content of cells.

While performing the update, the following renderers are invoked:
- `Grid.rowDetailsRenderer`
- `GridColumn.renderer`
- `GridColumn.headerRenderer`
- `GridColumn.footerRenderer`

It is not guaranteed that the update happens immediately (synchronously) after it is requested.

### scrollToColumn

**Type:** `(indexOrColumn: number | GridColumn<any>) => void`

Scrolls horizontally so that the column becomes visible in the viewport.

The column can be specified either by its index (among visible columns
in visual order) or by the column element itself.

### scrollToIndex

**Type:** `(...indexes: number[]) => void`

Scroll to a specific row index in the virtual list. Note that the row index is
not always the same for any particular item. For example, sorting or filtering
items can affect the row index related to an item.

The `indexes` parameter can be either a single number or multiple numbers.
The grid will first try to scroll to the item at the first index on the top level.
In case the item at the first index is expanded, the grid will then try scroll to the
item at the second index within the children of the expanded first item, and so on.
Each given index points to a child of the item at the previous index.

Using `Infinity` as an index will point to the last item on the level.

### selectItem

**Type:** `(item: any) => void`

Selects the given item.

## Static Methods

### setDefaultMultiSortPriority

**Type:** `any`

Sets the default multi-sort priority to use for all grid instances.
This method should be called before creating any grid instances.
Changing this setting does not affect the default for existing grids.

## Events

### active-item-changed

**Type:** [GridActiveItemChangedEvent](#gridactiveitemchangedevent)

Fired when the `activeItem` property changes.

### cell-activate

**Type:** [GridCellActivateEvent](#gridcellactivateevent)

Fired when the cell is activated with click or keyboard.

### cell-focus

**Type:** [GridCellFocusEvent](#gridcellfocusevent)

Fired when a cell is focused with click or keyboard navigation.

Use context property of @see {@link GridCellFocusEvent} to get detail information about the event.

### column-reorder

**Type:** [GridColumnReorderEvent](#gridcolumnreorderevent)

Fired when the columns in the grid are reordered.

### column-resize

**Type:** [GridColumnResizeEvent](#gridcolumnresizeevent)

Fired when a column in the grid is resized by the user.

### data-provider-changed

**Type:** [GridDataProviderChangedEvent](#griddataproviderchangedevent)

Fired when the `dataProvider` property changes.

### expanded-items-changed

**Type:** [GridExpandedItemsChangedEvent](#gridexpandeditemschangedevent)

Fired when the `expandedItems` property changes.

### grid-dragend

**Type:** `CustomEvent`

Fired when the dragging of the rows ends.

### grid-dragstart

**Type:** `CustomEvent`

Fired when starting to drag grid rows.

### grid-drop

**Type:** `CustomEvent`

Fired when a drop occurs on top of the grid.

### item-toggle

**Type:** [GridItemToggleEvent](#griditemtoggleevent)

Fired when the user selects or deselects an item through the selection column.

### loading-changed

**Type:** [GridLoadingChangedEvent](#gridloadingchangedevent)

Fired when the `loading` property changes.

### selected-items-changed

**Type:** [GridSelectedItemsChangedEvent](#gridselecteditemschangedevent)

Fired when the `selectedItems` property changes.

### size-changed

**Type:** [GridSizeChangedEvent](#gridsizechangedevent)

Fired when the `size` property changes.

## Types

### ColumnRendering

```ts
export type ColumnRendering = 'eager' | 'lazy';
```

### DataProvider

```ts
export type DataProvider<TItem, TDataProviderParams extends Record<string, unknown>> = (
  params: DataProviderDefaultParams & TDataProviderParams,
  callback: DataProviderCallback<TItem>,
) => void;
```

### DataProviderCallback

```ts
export type DataProviderCallback<TItem> = (items: TItem[], size?: number) => void;
```

### GridActiveItemChangedEvent

```ts
/**
 * Fired when the `activeItem` property changes.
 */
export type GridActiveItemChangedEvent<TItem> = CustomEvent<{ value: TItem | null | undefined }>;
```

### GridCellActivateEvent

```ts
/**
 * Fired when the cell is activated with click or keyboard.
 */
export type GridCellActivateEvent<TItem> = CustomEvent<{ model: GridItemModel<TItem> }>;
```

### GridCellFocusEvent

```ts
/**
 * Fired when a cell is focused with click or keyboard navigation.
 */
export type GridCellFocusEvent<TItem> = CustomEvent<{ context: GridEventContext<TItem> }>;
```

### GridCellPartNameGenerator

```ts
export type GridCellPartNameGenerator<TItem> = (column: GridColumn<TItem>, model: GridItemModel<TItem>) => string;
```

### GridColumnReorderEvent

```ts
/**
 * Fired when the columns in the grid are reordered.
 */
export type GridColumnReorderEvent<TItem> = CustomEvent<{ columns: Array<GridColumn<TItem>> }>;
```

### GridColumnResizeEvent

```ts
/**
 * Fired when the grid column resize is finished.
 */
export type GridColumnResizeEvent<TItem> = CustomEvent<{ resizedColumn: GridColumn<TItem> }>;
```

### GridDataProvider

```ts
export type GridDataProvider<TItem> = DataProvider<TItem, GridDataProviderParams<TItem>>;
```

### GridDataProviderChangedEvent

```ts
/**
 * Fired when the `dataProvider` property changes.
 */
export type GridDataProviderChangedEvent<TItem> = CustomEvent<{ value: GridDataProvider<TItem> }>;
```

### GridDataProviderParams

```ts
export type GridDataProviderParams<TItem> = {
  page: number;
  pageSize: number;
  filters: GridFilterDefinition[];
  sortOrders: GridSorterDefinition[];
  parentItem?: TItem;
};
```

### GridDragAndDropFilter

```ts
export type GridDragAndDropFilter<TItem> = (model: GridItemModel<TItem>) => boolean;
```

### GridDropMode

```ts
export type GridDropMode = 'between' | 'on-grid' | 'on-top-or-between' | 'on-top';
```

### GridEventContext

```ts
export interface GridEventContext<TItem> {
  section?: 'body' | 'details' | 'footer' | 'header';
  item?: TItem;
  column?: GridColumn<TItem>;
  index?: number;
  selected?: boolean;
  detailsOpened?: boolean;
  hasChildren?: boolean;
  expanded?: boolean;
  level?: number;
}
```

### GridExpandedItemsChangedEvent

```ts
/**
 * Fired when the `expandedItems` property changes.
 */
export type GridExpandedItemsChangedEvent<TItem> = CustomEvent<{ value: TItem[] }>;
```

### GridFilterDefinition

```ts
export interface GridFilterDefinition {
  path: string;
  value: string;
}
```

### GridItemModel

```ts
export interface GridItemModel<TItem> {
  index: number;
  item: TItem;
  selected?: boolean;
  expanded?: boolean;
  level?: number;
  detailsOpened?: boolean;
  hasChildren?: boolean;
}
```

### GridItemToggleEvent

```ts
/**
 * Fired when the user selects or deselects an item through the selection column.
 */
export type GridItemToggleEvent<TItem> = CustomEvent<{ item: TItem; selected: boolean; shiftKey: boolean }>;
```

### GridLoadingChangedEvent

```ts
/**
 * Fired when the `loading` property changes.
 */
export type GridLoadingChangedEvent = CustomEvent<{ value: boolean }>;
```

### GridRowDetailsRenderer

```ts
export type GridRowDetailsRenderer<TItem> = (root: HTMLElement, grid: Grid<TItem>, model: GridItemModel<TItem>) => void;
```

### GridSelectedItemsChangedEvent

```ts
/**
 * Fired when the `selectedItems` property changes.
 */
export type GridSelectedItemsChangedEvent<TItem> = CustomEvent<{ value: TItem[] }>;
```

### GridSizeChangedEvent

```ts
/**
 * Fired when the `size` property changes.
 */
export type GridSizeChangedEvent = CustomEvent<{ value: number }>;
```

### GridSorterDefinition

```ts
export interface GridSorterDefinition {
  path: string;
  direction: GridSorterDirection;
}
```

### GridSorterDirection

```ts
export type GridSorterDirection = 'asc' | 'desc' | null;
```