Dynamically create x-media-library-collection component

[Rexy-Gamaliel]

I'm using laravel-medialibrary-pro v2.7.3 and livewire v2.12.8 to make a form page for a content management system. I have 2 Laravel models: Partner and PartnerDocument in a one-to-many relationship. The PartnerDocument model contains some additional data for the file that is associated with it, so this model uses the Spatie\MediaLibraryPro\Http\Livewire\Concerns\WithMedia trait.

I've tried the example here and wondered how to apply it in a situation where the x-media-library-collection has to be created dynamically. My idea was to use an "Add" button that does the following:

1. in MyForm class:
   1.1. generate a random unique string $key, append it to $this->keys array
   1.2. create custom properties: $this->{'partner_document_' . $key} of type PartnerDocument and $this->{'media_' . $key}
   1.3. add 'media_' . $key to $this->mediaComponentNames
2. in MyForm's component blade template:

@foreach ( $keys as $key )
    @php
        $model = 'partner_document_' . $key;
        $media = 'media_' . $key;
    @endphp
    <x-media-library-collection
        :name="$media"
        :model="$this->{$model}"
        collection="attachments" />
@endforeach

Lastly, when the submit button is clicked, it calls save method as such:

use Livewire\Component;

class MyForm extends Component {
    ...
    public function save() {
        ...
        foreach ( $this->keys as $key ) {
            $model = 'model_' . $key;
            $media = 'media_' . $key;
            $this->$model->addFromMediaLibraryRequest($this->$media)
                        ->toMediaCollection('attachments');
        }
    }
    ...
}

But the uploaded file cannot be associated with the model. On the media table, it is associated with Spatie\MediaLibraryPro\Models\TemporaryUpload but not PartnerDocument. The property $this->$media is always an empty array.

I've been trying to make it work for quite a while but can't seem to find a solution. Any help is greatly appreciated, thank you!