Dealing with Dependencies in Active Record Models — Option #3: Composing a new domain object

Invitation.php

<?php

// The Domain Object
class Invitation
{
    private $invitationRecord;
    private $mailer;

    public function __construct(InvitationRecord $invitationRecord, Mailer $mailer)
    {
        $this->invitationRecord = $invitationRecord;
        $this->mailer = $mailer;
    }

    public function send()
    {
        $this->mailer->send('emails.invitation', ['invited_by' => $this->invitationRecord->user], function ($m) {
            $m->to($this->invitationRecord->recipient)->subject("You've been invited to my app!");
        });
    }
}

InvitationBuilder.php

<?php

class InvitationBuilder
{
    private $mailer;

    public function __construct(Mailer $mailer)
    {
        $this->mailer = $mailer;
    }

    public function create($recipient, $invitedBy)
    {
        $invitationRecord = InvitationRecord::create([
            'recipient' => $recipient,
            'invited_by' => $invitedBy->id,
        ]);

        return new Invitation($invitationRecord, $this->mailer);
    }
}

InvitationRecord.php

<?php

// The Active Record model
class InvitationRecord extends Model
{
    protected $table = 'invitations';

    public function user()
    {
        return $this->belongsTo(User::class, 'invited_by');
    }
}

InvitationsController.php

<?php

class InvitationsController extends Controller
{
    private $invitationBuilder;

    public function __construct(InvitationBuilder $invitationBuilder)
    {
        $this->invitationBuilder = $invitationBuilder;
    }

    public function store()
    {
        $recipient = request('recipient');
        $invitedBy = auth()->user();

        $invitation = $this->invitationBuilder->create($recipient, $invitedBy);
        $invitation->send();

        return response('', 204);
    }
}