contextdart 1.2.0

pure golang context.Context implements in dart

pure golang context.Context implements in dart

Totally inspected by context.Context from golang, and dart style fit.

Usage

inject value or singleton in context

import 'package:contextdart/contextdart.dart';

class Logger {
  info(String msg) {
    
  }
}

void main() async {
  var ctx = Context.withValue(Logger());

  ctx.run(() {
    var log = Context.value<Logger>();

    log?.info("log");
  });
}

Cancelable context.

import 'package:contextdart/contextdart.dart';

class Logger {
  info(String msg);
}

void main() async {
  var cctx = Context.withCancel();

  cctx.run(() {
    doAction();
    doDBAction();

    // cancel 
    cctx.cancel();
  });
}

doAction() async {
  return await Future.any([
    // if canceled, should ignore real action
    Context.done?.fisrt,
    Future(() => "do action"),
  ].whereType<Future>());
}

doDBAction() async {
  Context.done?.listen(() {
    // do some think like db rollback.
  });
}