---
title: "CallableStrategy"
description: "Wrap a closure as a translation backend – the simplest extension point and the migration path off the old translateFn option."
canonical_url: "https://kirby.tools/docs/content-translator/php-classes/strategies/callable-strategy"
---
# CallableStrategy
> Wrap a closure as a translation backend – the simplest extension point and the migration path off the old translateFn option.
Wrap a closure as a `Strategy`. The closure runs once per text – no batching. Reach for a custom `Strategy` implementation when batching matters.
This is what wraps the deprecated `translateFn` option behind the scenes. New code should set `strategy => $closure` directly, or implement `Strategy` for batching support.
## Construction
```php
public function __construct(Closure $translate)
```
Translation function. Returns the translated text. The same signature as the legacy `translateFn`.
## Usage
```php [config.php]
return [
'johannschopplich.content-translator' => [
'strategy' => function (string $text, string $target, ?string $source): string {
return myTranslateFunction($text, $target, $source);
},
],
];
```
The closure is auto-wrapped in `CallableStrategy`.
```php
use JohannSchopplich\ContentTranslator\Translation\Strategies\CallableStrategy;
return [
'johannschopplich.content-translator' => [
'strategy' => new CallableStrategy(
fn (string $text, string $target, ?string $source) => myTranslateFunction($text, $target, $source),
),
],
];
```
## When to Use Something Else
`CallableStrategy` is fine for low-volume sites and `translateFn` migration. For batching, per-field dispatch, or structured exceptions, see [Implementing a Custom Strategy](/docs/content-translator/php-classes/strategies#implementing-a-custom-strategy).
---
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