---
product: "AG Grid"
title: "External Filter"
description: "External filtering allows custom filtering logic to be mixed with the grid's inbuilt filtering."
framework: react
version: "36.2.0"
related:
    - title: "Overview"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/filtering-overview/"
    - title: "Column Filters"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/filtering/"
    - title: "Custom Column Filters"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/component-filter/"
    - title: "Floating Filters"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/floating-filters/"
    - title: "Custom Floating Filters"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/component-floating-filter/"
    - title: "Advanced Filter"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/filter-advanced/"
    - title: "Quick Filter"
      url: "https://www.ag-grid.com/archive/36.2.0/react-data-grid/filter-quick/"
llms: "https://www.ag-grid.com/archive/36.2.0/llms.txt"
---

# External Filter

External filtering allows custom filtering logic to be mixed with the grid's inbuilt filtering.

> **Warning**
>
> This form of filtering is only compatible with the Client-Side Row Model, see [Row Models](https://www.ag-grid.com/archive/36.2.0/react-data-grid/row-models/) for more details.

#### External Filter

```tsx
import { useFetchJson } from './useFetchJson';
"use client";

import React, { StrictMode, useCallback, useMemo, useState } from "react";
import { createRoot } from "react-dom/client";

import type { ColDef, IDateFilterParams, IRowNode } from "ag-grid-community";
import {
  ClientSideRowModelModule,
  DateFilterModule,
  ExternalFilterModule,
  NumberFilterModule,
  enableDevValidations,
} from "ag-grid-community";
import {
  ColumnMenuModule,
  ColumnsToolPanelModule,
  ContextMenuModule,
  SetFilterModule,
} from "ag-grid-enterprise";
import { AgGridProvider, AgGridReact } from "ag-grid-react";

import type { IOlympicData } from "./interfaces";
import "./styles.css";

if (process.env.NODE_ENV !== "production") {
  // Enable extended validations only for development
  enableDevValidations();
}

const modules = [
  ExternalFilterModule,
  ClientSideRowModelModule,
  ColumnsToolPanelModule,
  ColumnMenuModule,
  ContextMenuModule,
  SetFilterModule,
  NumberFilterModule,
  DateFilterModule,
];

const asDate = (dateAsString: string): Date => {
  const splitFields = dateAsString.split("/");
  return new Date(
    Number.parseInt(splitFields[2]),
    Number.parseInt(splitFields[1]) - 1,
    Number.parseInt(splitFields[0]),
  );
};

const dateFilterParams: IDateFilterParams = {
  comparator: (filterLocalDateAtMidnight: Date, cellValue: string) => {
    const cellDate = asDate(cellValue);

    if (filterLocalDateAtMidnight.getTime() === cellDate.getTime()) {
      return 0;
    }
    if (cellDate < filterLocalDateAtMidnight) {
      return -1;
    }
    if (cellDate > filterLocalDateAtMidnight) {
      return 1;
    }
    return 0;
  },
};

const defaultColDef: ColDef = { flex: 1, minWidth: 120, filter: true };
const columnDefs: ColDef<IOlympicData>[] = [
  { field: "athlete", minWidth: 180 },
  { field: "age", filter: "agNumberColumnFilter" },
  { field: "country" },
  { field: "year" },
  {
    field: "date",
    filter: "agDateColumnFilter",
    filterParams: dateFilterParams,
  },
  { field: "total", filter: "agNumberColumnFilter" },
];

const GridExample = () => {
  const [ageType, setAgeType] = useState("everyone");

  const { data, loading } = useFetchJson<IOlympicData>(
    "https://www.ag-grid.com/example-assets/olympic-winners.json",
  );

  // Both callbacks depend on ageType, so changing it hands the grid new references and filtering re-runs.
  const isExternalFilterPresent = useCallback(
    (): boolean => ageType !== "everyone",
    [ageType],
  );

  const doesExternalFilterPass = useCallback(
    (node: IRowNode<IOlympicData>): boolean => {
      if (node.data) {
        switch (ageType) {
          case "below25":
            return node.data.age < 25;
          case "between25and50":
            return node.data.age >= 25 && node.data.age <= 50;
          case "above50":
            return node.data.age > 50;
          case "dateAfter2008":
            return asDate(node.data.date) > new Date(2008, 0, 1);
          default:
            return true;
        }
      }
      return true;
    },
    [ageType],
  );

  return (
    <AgGridProvider modules={modules}>
      <div className="test-container">
        <div className="test-header">
          <label>
            <input
              type="radio"
              name="filter"
              id="everyone"
              defaultChecked
              onChange={() => setAgeType("everyone")}
            />
            Everyone
          </label>
          <label>
            <input
              type="radio"
              name="filter"
              id="below25"
              onChange={() => setAgeType("below25")}
            />
            Below 25
          </label>
          <label>
            <input
              type="radio"
              name="filter"
              id="between25and50"
              onChange={() => setAgeType("between25and50")}
            />
            Between 25 and 50
          </label>
          <label>
            <input
              type="radio"
              name="filter"
              id="above50"
              onChange={() => setAgeType("above50")}
            />
            Above 50
          </label>
          <label>
            <input
              type="radio"
              name="filter"
              id="dateAfter2008"
              onChange={() => setAgeType("dateAfter2008")}
            />
            After 01/01/2008
          </label>
        </div>
        <div style={{ height: "100%" }}>
          <AgGridReact<IOlympicData>
            rowData={data}
            loading={loading}
            columnDefs={columnDefs}
            defaultColDef={defaultColDef}
            isExternalFilterPresent={isExternalFilterPresent}
            doesExternalFilterPass={doesExternalFilterPass}
          />
        </div>
      </div>
    </AgGridProvider>
  );
};

const root = createRoot(document.getElementById("root")!);
root.render(
  <StrictMode>
    <GridExample />
  </StrictMode>,
);
```

[Live example: External Filter](https://www.ag-grid.com/archive/36.2.0/examples/filter-external/external-filter/reactFunctionalTs/)

## Implementing External Filtering

The example above shows external filters in action. Two methods on `gridOptions` are required to be implemented: `isExternalFilterPresent` and `doesExternalFilterPass`.

| Property | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `isExternalFilterPresent` | `IsExternalFilterPresent` |  |  |  |
| `doesExternalFilterPass` | `DoesExternalFilterPass` |  |  |  |

## Re-running the External Filter

The filter state is held outside the grid, so the grid has to be told when that state has changed. Pick one of the following approaches:

- [Calling onFilterChanged](https://www.ag-grid.com/archive/36.2.0/react-data-grid/filter-external/#calling-onfilterchanged) - the callback references are kept stable and the filter is re-run only when the API is called.
- [Supplying New Callbacks](https://www.ag-grid.com/archive/36.2.0/react-data-grid/filter-external/#supplying-new-callbacks) - a new callback reference is handed to the grid and the filter is re-run automatically.

### Calling onFilterChanged

After the filter state has changed call `api.onFilterChanged()` to ask the grid to run filtering again.

| Property | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `onFilterChanged` | `FilterChangedEventSourceType` |  |  |  |

```js
// Filter state updated now re-run filtering
api.onFilterChanged();
```

Ensure the callbacks have stable references to avoid triggering filtering excessively.

> **Warning**
>
> Avoid passing an inline lambda as it will provide a new function on every render, so the grid re-filters every time the component renders:
>
> ```jsx
> // re-filters on every render
> <AgGridReact doesExternalFilterPass={(node) => node.data.age > minAge} />
> ```

### Supplying New Callbacks

`isExternalFilterPresent` and `doesExternalFilterPass` are reactive grid properties, so replacing either one with a new function re-runs filtering automatically.

Where the filter value is held in state ensure this is included in the callback dependency array so that the grid receives a new reference each time it changes to trigger filtering.

```jsx
const [ageType, setAgeType] = useState('everyone');

const isExternalFilterPresent = useCallback(() => ageType !== 'everyone', [ageType]);
const doesExternalFilterPass = useCallback((node) => ageType === 'everyone' || node.data.age > 50, [ageType]);
```

The example on this page takes the second path: `ageType` is component state, and both callbacks list it as a dependency.