How to add PDF attachment in queue mails In Laravel?

I was able to send an email but when I put the attachData() in the UserMail there was an error. I think because of the parameter $this->pdf that should be declared in UserEmailJob, and I don't know how to fix it.

UserEmailJob

public $details;
/**
 * Create a new job instance.
 *
 * @return void
 */
public function __construct($details)
{
    $this->details = $details;
}

/**
 * Execute the job.
 *
 * @return void
 */
public function handle()
{
    $email = new UserEmail();
    Mail::to($this->details['email'])->send($email);
}

UserEmail - mail class
I'm having error with this line $this->pdf->output()

public function __construct()
{

}

/**
 * Build the message.
 *
 * @return $this
 */
public function build()
{
    return $this->from('info@gmail.com', 'Mailtrap')
        ->subject('Stock Report - Laravel Tutorial')
        ->view('emails.userEmail')
        ->attachData($this->pdf->output(), 'stock_report.pdf');
}

UserController

public function mailClass()
{
    $users = User::all();
    $data['name'] = 'Hi';

    $pdf = app('dompdf.wrapper');
    $pdf->loadView('cert', $data);
    $pdf->setPaper('A4', 'landscape');

    $details = ['email' => 'abc@gamil.com'];
    UserEmailJob::dispatch($details);
    return response()->json(['status' => 'success', 'message' => 'Report has been sent successfully.']);
}

Because $this->pdf is not defined in your class.

try this:

private $pdf;

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

public function build(){

      return $this->from('info@gmail.com', 'Mailtrap')
        ->subject('Stock Report - Laravel Tutorial')
        ->view('emails.userEmail')
        ->attach($this->pdf);
    }

and in your UserController

UserEmailJob::dispatch($details, $pdf->output());

So modify it

public $details;
    public $pdfStream;
        /**
         * Create a new job instance.
         *
         * @return void
         */
        public function __construct($details, $pdfStream)
        {
            $this->details = $details;
            $this->pdfStream = $pdfStream;
        }
    
    public function handle()
    {
        $email = new UserEmail($this->pdfStream);
        Mail::to($this->details['email'])->send($email);
    }

EDIT: it is probably not recommended to stream the pdf via json

UserEmailJob

public $details;
public $data;
/**
 * Create a new job instance.
 *
 * @return void
 */
public function __construct($details, $data)
{
    $this->details = $details;
    $this->data = $data;
}

/**
 * Execute the job.
 *
 * @return void
 */
public function handle()
{
    $email = new UserEmail($this->data);
    Mail::to($this->details['email'])->send($email);
    
    
    }

UserEmail

private $data;
    
    public function __construct($data)
{
        $this->data = $data;
}

/**
 * Build the message.
 *
 * @return $this
 */
public function build()
{
    $pdf = app('dompdf.wrapper');
    $pdf->loadView('cert', $this->data);
    $pdf->setPaper('A4', 'landscape');
    
    return $this->from('info@gmail.com', 'Mailtrap')
        ->subject('Stock Report - Laravel Tutorial')
        ->view('emails.userEmail')
        ->attachData($pdf->output(), 'stock_report.pdf');
}

UserController

public function mailClass()
{
    $users = User::all();
    $data['name'] = 'Hi';
    $details = ['email' => 'abc@gamil.com'];
    UserEmailJob::dispatch($details, $data);
    return response()->json(['status' => 'success', 'message' => 'Report has been sent successfully.']);
}