stream method

@override Stream<String> stream(File file)

Extracts text content from a file and returns it as a stream of strings.

Implementing classes must define how to parse their specific file format. @param file The file to extract text from

Implementation

@override
Stream<String> stream(File file) async* {
  Excel x = Excel.decodeBytes(await file.readAsBytes());

  for (String table in x.tables.keys) {
    yield table;
    yield "\n";
    for (var row in x.tables[table]!.rows) {
      StringBuffer buffer = StringBuffer();
      for (Data? cell in row) {
        buffer.write(",");
        CellValue? value = cell?.value;
        buffer.write(switch (value) {
          TextCellValue() => value.value,
          FormulaCellValue() => value.formula,
          IntCellValue() => value.value.toString(),
          DoubleCellValue() => value.value.toString(),
          BoolCellValue() => value.value.toString(),
          DateCellValue() => value.asDateTimeUtc().toIso8601String(),
          TimeCellValue() =>
            '${value.hour}h:${value.minute}m:${value.second}s',
          DateTimeCellValue() => value.asDateTimeUtc().toIso8601String(),
          null => "",
        });
      }

      buffer.write("\n");
      yield buffer.toString().substring(1);
    }

    yield "\n\n";
  }
}