Creating a custom image generator

If you want to generate a conversion for a file type that is not covered out of the box you can easily create your own media generator.

Generators can only be used to generate images, intended to be used as a thumbnail representation of files. Converting to any other file format other than images is unsupported.

In the following example we'll create a custom generator that can convert a Powerpoint to an image.

##Creating a custom image generator

The first step for creating a custom generator is to create a class that extends Spatie\MediaLibrary\Conversions\ImageGenerators\ImageGenerator:

use Illuminate\Support\Collection;
use Spatie\MediaLibrary\Conversions\Conversion;
use Spatie\MediaLibrary\Conversions\ImageGenerators\ImageGenerator;

class PowerPoint extends ImageGenerator
{
    /**
    * This function should return a path to an image representation of the given file.
    */
    public function convert(string $file, Conversion $conversion = null) : string
    {
        $pathToImageFile = pathinfo($file, PATHINFO_DIRNAME).'/'.pathinfo($file, PATHINFO_FILENAME).'.jpg';

        // Here you should convert the file to an image and return generated conversion path.
        \PowerPoint::convertFileToImage($file)->store($pathToImageFile);

        return $pathToImageFile;
    }

    public function requirementsAreInstalled() : bool
    {
        return true;
    }

    public function supportedExtensions() : Collection
    {
        return collect(['ppt', 'pptx']);
    }

    public function supportedMimeTypes() : Collection
    {
        return collect([
            'application/vnd.ms-powerpoint',
            'application/vnd.openxmlformats-officedocument.presentationml.presentation'
        ]);
    }
}

##Registering the custom generator

After creating your custom image generator, you should add the class name to the image_generators key of the media-library config file.

// in config/laravel-medialibrary.php
'image_generators' => [
    // ...
    YourImageGenerator::class,
], 

##Passing configuration to a custom image generator

When registering a custom image generator in the media-library config file, you can pass values like this

// in config/laravel-medialibrary.php
'image_generators' => [
    // ...
    YourImageGenerator::class => ['myArgument' => 'value', 'myOtherArgument' => 'otherValue'],
], 

In your custom image generator you can accept those arguments in the constructor.

class YourImageGenerator
{
    public function __construct(string $myArgument, string $myOtherArgument)
    {
        // do something with these arguments
    }
}

##Only using a custom image generator a specific model

If the generator only needs to be applied to one of your models you can override the getImageGenerators in that model like this:

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Spatie\MediaLibrary\InteractsWithMedia;
use Spatie\MediaLibrary\Interfaces\HasMedia;

class News extends Model implements HasMedia
{
   ...

   /**
    * Collection of all ImageGenerator drivers.
    */
   public function getImageGenerators() : Collection
   {
       return parent::getImageGenerators()->push(\App\ImageGenerators\PowerPoint::class);
   }
}