sendZplToPrinter method

Future<String> sendZplToPrinter(String macAddress, String zplData)

Sends ZPL code to the printer

macAddress MAC address of the printer zplData ZPL code

Returns result message if successful, throws an error if failed

Implementation

Future<String> sendZplToPrinter(String macAddress, String zplData) async {
  if (macAddress.isEmpty) {
    throw Exception("MAC address cannot be empty.");
  }
  try {
    // If ZPL code already starts with ^XA and ends with ^XZ, send as is
    final String finalZplToSend;
    if (zplData.trim().startsWith("^XA") && zplData.trim().endsWith("^XZ")) {
      finalZplToSend = zplData;
    } else {
      // Otherwise, wrap the ZPL code between ^XA and ^XZ
      const String initCommands = "^XA";
      finalZplToSend = "$initCommands$zplData^XZ";
    }

    final String result = await _channel.invokeMethod('printLabel', {'address': macAddress, 'data': finalZplToSend});
    return result;
  } on PlatformException catch (e) {
    throw Exception("Print Error (${e.code}): ${e.message}");
  }
}