Thumb component for document

Kirby 3 Questions 🤔
4

That’s how I create thumbs for my pdf files:

'file.create:after' => function (Kirby\Cms\File $file) {
    if ($file->template() == "flyer") {
        $im = new Imagick();
        $im->setResolution(72,72);
        $im->readimage($file->root() . '[0]');
        $im->setImageFormat('jpeg');
        $im->writeImage(dirname($file->root()) . '/' . $file->name() . '.jpg'); // temp
        $im->clear();
        $im->destroy();

        Kirby\Cms\File::create([
            'source'     => dirname($file->root()) . '/' . $file->name() . '.jpg',
            'parent'     => $file->page(),
            'filename'   => $file->name() . '-preview.jpg',
            'template'   => 'preview'
        ]);

        Kirby\Toolkit\F::remove(dirname($file->root()) . '/' . $file->name() . '.jpg'); // delete temp
    }
},

And I realize that I am not checking if it actually is a pdf. So I might should do that before creating the thumb…