gistfile1.php

    public function Preview(Request $request)
    {
        $inputs = $request->all();

        $invoiceItems = array_map(function ($quantity, $description, $price) {
            return [
                'quantity' => $quantity,
                'description' => $description,
                'price' => $price
            ];
        }, $inputs['quantity'], $inputs['description'], $inputs['price']);

        $client = Client::find($inputs['client']);

        //combine dates
        $due_date = $request->year .'-'.$request->month .'-'.$request->day;

        //Save invoice
        $invoice = new Invoice;
        $invoice->client_id = $request->client;
        $invoice->user_id = Auth::user()->id;
        $invoice->due_date = $due_date;
        $invoice->status = 'created';
        $invoice->amount = $request->amount;
        $invoice->save();

        foreach ($invoiceItems as $invoiceItem)
        {
            $invoiceDB = new InvoiceItem;
            $invoiceDB->invoice_id    = $invoice->id;
            $invoiceDB->quantity      = $invoiceItem['quantity'];
            $invoiceDB->description   = $invoiceItem['description'];
            $invoiceDB->price         = $invoiceItem['price'];
            $invoiceDB->save();
        }

        return view('invoices.preview', compact('inputs', 'client', 'invoiceItems'));
    }