Transaction<T> class

The transaction class is an easy way to use the UsbPort class in a more linear way without blocking.

Example

// Create a parser that splits incoming data on endline newline combination ( \r\n)
var c = Transaction.terminated(p.inputStream, Uint8List.fromList([13, 10]));

// Listen asynchronously if you need this:
c.stream.listen((data) {
  print("ASYNC LISTEN $data");
});

var request_1 = Uint8List.fromList([65]);
// Wait two seconds for the answer

Uint8List response_1 = await c.transaction(p, request_1, Duration(seconds: 2));
if (response_1 == null ) {
   print("Failed to get a response.");
}

Constructors

Transaction(Stream<Uint8List> stream, DisposableStreamTransformer<Uint8List, T> transformer)

Transaction Constructor, pass it the untransformed input stream and the transformer to work on the stream.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

stream ↔ Stream<T>

getter/setter pair

Methods

dispose() → void

Call dispose when you are done with the object. this will release the underlying stream.

flush() → Future<void>

Flush all existing messages from the queue.

getMsg(Duration duration) → Future<T?>

Get the next message from the queue if any. returns data or null on error.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

transaction(AsyncDataSinkSource port, Uint8List message, Duration duration) → Future<T?>

The transaction functions does 3 things.

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

magicHeader(Stream<Uint8List> stream, List<int> header) → Transaction<Uint8List>

Create a transaction that uses MagicHeaderAndLengthByteTransformer

stringTerminated(Stream<Uint8List> stream, Uint8List terminator) → Transaction<String>

Create a transaction that transforms the incoming stream into events delimited by 'terminator', returning Strings.

terminated(Stream<Uint8List> stream, Uint8List terminator) → Transaction<Uint8List>

Create a transaction that transforms the incoming stream into events delimited by 'terminator'.