App\Http\Controllers\InvoiceController::emailInvoice PHP Method

    private function emailInvoice($invoice, $pdfUpload)
    {
        $entityType = $invoice->getEntityType();
        $pdfUpload = Utils::decodePDF($pdfUpload);
        if (!Auth::user()->confirmed) {
            $errorMessage = trans(Auth::user()->registered ? 'texts.confirmation_required' : 'texts.registration_required');
            Session::flash('error', $errorMessage);
            return Redirect::to('invoices/' . $invoice->public_id . '/edit');
        }
        if ($invoice->is_recurring) {
            $response = $this->emailRecurringInvoice($invoice);
        } else {
            $response = $this->mailer->sendInvoice($invoice, false, $pdfUpload);
        }
        if ($response === true) {
            $message = trans("texts.emailed_{$entityType}");
            Session::flash('message', $message);
        } else {
            Session::flash('error', $response);
        }
    }