blob: ca146d669aa987acf9d8195b70babfb71532c92f [file] [log] [blame]
// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:meta/meta.dart';
import 'step.dart';
/// The types of errors that can be encountered while a step is running.
enum Error { undefined }
/// Interface for sending results from [Action] clients.
/// ignore: one_member_abstracts
abstract class ActionResultSender {
void sendResult(String result);
/// Interface for receiving results from an [Action].
/// ignore: one_member_abstracts
abstract class ActionResultReceiver {
void onResult(ActionResult result);
/// Instructions for assembling an [Action].
abstract class Blueprint {
/// The name of the action
final String key;
/// A description of the action. Used for logging and debugging purposes
final String description;
/// Default constructor requires at least the action name
Blueprint(this.key, this.description);
/// Creates an instance of the action for use
Action assemble(Step step, ActionResultReceiver callback);
/// A running action instance generated from a [Blueprint].
abstract class Action<T extends Blueprint> {
final T blueprint;
final Step step;
final ActionResultReceiver callback;
Action(this.step, this.blueprint, this.callback);
/// Called by client to return result
void onResult(String result) {
callback.onResult(ActionResult(step, result));
/// Called by owner to start the action
void launch();
/// A store for action names mapped to steps.
class Roster {
final Map<String, Blueprint> _plans = {};
/// Adds the specified [Blueprint] to the roster using its action name
/// as the key.
void add(Blueprint blueprint) {
_plans[blueprint.key] = blueprint;
/// Searches for a [Blueprint] matching the [Step]'s action and then assembles
/// an [Action] with the given [ActionResultReceiver].
Action getAction(Step step, ActionResultReceiver callback) {
return _plans.containsKey(step.action)
? _plans[step.action].assemble(step, callback)
: null;
int get actionCount => _plans.length;
/// A PODO for capturing a step's execution results.
class ActionResult {
/// The associated Step.
final Step step;
/// The return code from the step that can be used to map to the next step
/// to transition to. Note this can be null.
final String code;
/// The type of error if one is encountered during the step. In a normal
/// expected flow, this should be null.
final Error error;
ActionResult(this.step, this.code, [this.error]);