---
title: Configuration
description: Constructor options for eSheep\Twigs\Extension — inject a configured TailwindMerge instance and set the default options of the merge_attributes filter.
sidebar:
  order: 3
---

The extension works without configuration. Its constructor takes two optional named arguments.

```php
use eSheep\Twigs\Extension;
use TalesFromADev\TailwindMerge\TailwindMerge;

$twig->addExtension(new Extension(
    tailwindMerge: new TailwindMerge(),
    mergeOptions: [
        'remove_duplicate_classes' => true,
        'tailwind_merge' => true,
    ],
));
```

## `tailwindMerge`

An instance of `TalesFromADev\TailwindMerge\TailwindMergeInterface`, used by [`|tailwind_merge`](/twigs/reference/filters#tailwind_merge) and by [`|merge_attributes`](/twigs/reference/filters#merge_attributes).

Without one, the extension creates a `TailwindMerge` with the default configuration the first time it needs to merge classes. Pass your own to use a custom Tailwind configuration or a PSR-16 cache:

```php
use TalesFromADev\TailwindMerge\TailwindMerge;

$twig->addExtension(new Extension(
    tailwindMerge: new TailwindMerge(
        additionalConfiguration: [/* see the tailwind-merge-php docs */],
        cache: $psr16Cache,
    ),
));
```

The options `additionalConfiguration` accepts are covered in the [tailwind-merge-php documentation](https://github.com/tales-from-a-dev/tailwind-merge-php/blob/main/docs/index.md#configuration).

## `mergeOptions`

Defaults for [`|merge_attributes`](/twigs/reference/filters#merge_attributes). A call can still override them through the filter's third argument.

| Key | Type | Default | Effect |
| --- | --- | --- | --- |
| `remove_duplicate_classes` | `bool` | `true` | Removes repeated class names after merging. |
| `tailwind_merge` | `bool` | `true` | Resolves conflicting Tailwind classes after merging, so later classes win. |

If your project doesn't use Tailwind CSS, turn off `tailwind_merge`. Otherwise classes that happen to look like Tailwind utilities can be dropped:

```php
$twig->addExtension(new Extension(
    mergeOptions: ['tailwind_merge' => false],
));
```