# BaseFilterPanel

> _Since v0.13.0_

Base class for Angular filter panel components.

Provides a ready-made `params` input and common lifecycle helpers
(`applyAndClose`, `clearAndClose`) so consumers only need to implement
their filter logic in `applyFilter()`.

## Usage

```typescript
import { Component, viewChild, ElementRef } from '@angular/core';
import { BaseFilterPanel } from '@toolbox-web/grid-angular';

@Component({
  selector: 'app-text-filter',
  template: `
    <input #input (keydown.enter)="applyAndClose()" />
    <button (click)="applyAndClose()">Apply</button>
    <button (click)="clearAndClose()">Clear</button>
  `
})
export class TextFilterComponent extends BaseFilterPanel {
  input = viewChild.required<ElementRef<HTMLInputElement>>('input');

  applyFilter(): void {
    this.params().applyTextFilter('contains', this.input().nativeElement.value);
  }
}
```

## Template Syntax

The grid's filtering plugin will mount this component and provide `params`
automatically. No manual wiring is required:

```typescript
gridConfig = {
  columns: [
    { field: 'name', filterable: true, filterPanel: TextFilterComponent },
  ],
};
```

## Properties

| Property | Type | Description |
| -------- | ---- | ----------- |
| `params` | <code>InputSignal&lt;<a href="/grid/plugins/filtering/interfaces/filterpanelparams/">FilterPanelParams</a>&gt;</code> | Filter panel parameters injected by the grid's filtering plugin. |

## Methods

### applyFilter()

Implement this to apply your filter logic.

Called by applyAndClose before closing the panel.
Use `this.params()` to access the filter API.

```ts
applyFilter(): void
```

***

### applyAndClose()

Apply the filter then close the panel.

Calls applyFilter followed by `params().closePanel()`.
Bind this to your "Apply" button or Enter key handler.

```ts
applyAndClose(): void
```

***

### clearAndClose()

Clear the filter then close the panel.

Calls `params().clearFilter()` followed by `params().closePanel()`.
Bind this to your "Clear" / "Reset" button.

```ts
clearAndClose(): void
```

***