xstate.dart

WIP xstate for dart & flutter

Example

CD Player:

final machine = Machine.fromJson({
  "key": "cd",
  "initial": "not_loaded",
  "states": {
    "not_loaded": {
      "on": {"INSERT_CD": "loaded"}
    },
    "loaded": {
      "initial": "stopped",
      "on": {"EJECT": "not_loaded"},
      "states": {
        "stopped": {
          "on": {"PLAY": "playing"}
        },
        "playing": {
          "on": {
            "STOP": "stopped",
            "EXPIRED_END": "stopped",
            "EXPIRED_MID": "playing",
            "PAUSE": "paused"
          }
        },
        "paused": {
          "initial": "not_blank",
          "states": {
            "blank": {
              "on": {"TIMER": "not_blank"}
            },
            "not_blank": {
              "on": {"TIMER": "blank"}
            }
          },
          "on": {"PAUSE": "playing", "PLAY": "playing", "STOP": "stopped"}
        }
      }
    }
  }
});

machine.start(); // not_loaded
machine.transition('not_loaded', 'INSERT_CD'); // loaded.stopped
machine.transition('loaded.paused', 'EJECT'); // not_loaded

Roadmap & Features

Core

• Core FSM and functions. machine.start() , machine.transition(current, event) & state.matches('state')
• Basic support for Hierarchical or Nested State Machines. State(child: Machine ...
• Complete implementation of Statecharts (guards, context, ...)
• Parallel State Machines
• History States
• Refrence by id. State(on: {"2": '#B'})
• Machine.fromJson({}) ability to create machines with JSON Schema
• Machine.fromSCXML('<></>') ability to create machines with SCXML
• Binding package for flutter
• Binding package for flutter_hook
• Utility package for writing tests
• More tests

Tooling

• Run a webserver in watch mode and show all the machines in xstatejs's visualizer

Dart Analyzer Plugin

• Show outline for a machine and its states

• [Quick Fix] Convert Machine.fromJson({}) & Machine.fromSCXML('<></>') to Machine()
• [Quick Fix] Convert Machine() to Machine.fromJson({}) or Machine.fromSCXML('<></>')
• [Diagnostic] machine.maches('state.state_that_doesnt_exists') validation. (throw state_that_doesnt_exists doesn't exists on the machine)
• [Diagnostic] Provide warning and errors when creating a machine for invalid transition, invalid paths and unused event and states.
• [Quick Fix] Extract nested machines.