RobotlegsJS Macrobot

Macrobot is a macro command utility for RobotlegsJS which provides the ability to execute batches of commands in sequential or parallel fashion. It was originally implemented by Alessandro Bianco in AS3 and now is ported to TypeScript.

Introduction

While using RobotlegsJS and encapsulating your business logic inside commands, you may find yourself in a situation where you wish to batch commands, instead of relying on events to trigger every step.

Macrobot simplifies the process and provide two ways to group commands:

• Sequence: The commands will be executed in order one after the other. A command will not be executed until the previous one is complete. The macro itself will not be complete until all its commands are complete.

• Parallel: The commands will be executed as quickly as possible, with no regards to the order in which they were registered. The macro itself will not be complete until all its commands are complete.

Installation

You can get the latest release and the type definitions using NPM:

npm install @robotlegsjs/macrobot --save-prod

Or using Yarn:

yarn add @robotlegsjs/macrobot

Usage

To create a macro command, extend one of the two classes Macrobot provides: SequenceMacro or ParallelMacro. Override the prepare() method and add sub commands by calling add() specifying the command class to use. At the appropriate time, the command will be created, instantiated by satisfying the injection points and then executed. This automated process of instantiation, injection, and execution is very similar to how commands are normally prepared and executed in RobotlegsJS.

You could use Guards and Hooks as you would normally use with regular commands to control the execution workflow. Additionally you could use the withPayloads() method to add some data that can be used to satisfy the injection points of the sub commands. The data provided will be available to the guards and hooks applied to the sub command as well.

Here's an example of a simple sequential macro:

import { injectable } from "@robotlegsjs/core";

import { SequenceMacro } from "@robotlegsjs/macrobot";

@injectable()
export class MyMacro extends SequenceMacro {
    public prepare(): void {
        this.add(CommandA);
        this.add(CommandB);
        this.add(CommandC);
    }
}

And here's an example of a simple parallel macro:

import { injectable } from "@robotlegsjs/core";

import { ParallelMacro } from "@robotlegsjs/macrobot";

@injectable()
export class MyMacro extends ParallelMacro {
    public prepare(): void {
        this.add(AwaitForCommand).withPayloads(25);
        this.add(AwaitForCommand).withPayloads(50);
        this.add(AwaitForCommand).withPayloads(75);
    }
}

Using Guards

Guards are used to approve or deny the execution of one of the subcommands.

import { injectable, IGuard } from "@robotlegsjs/core";

import { SequenceMacro } from "@robotlegsjs/macrobot";

@injectable()
export class DailyRoutine extends SequenceMacro {
    public prepare() {
        this.add(Work);
        this.add(Party).withGuards(IsFriday); // It will only party on fridays
        this.add(Sleep);
    }
}

@injectable()
class IsFriday implements IGuard {
    public approve():boolean {
        return (new Date()).getDay() === 5;
    }
}

Using Hooks

Hooks run before the subcommands. They are typically used to run custom actions based on environmental conditions. Hooks will run only if the applied Guards approve the execution of the command.

import { inject, injectable, IGuard, IHook } from "@robotlegsjs/core";

import { SequenceMacro } from "@robotlegsjs/macrobot";

@injectable()
export class DailyRoutine extends SequenceMacro {
    public prepare() {
        this.add(Work);
        this.add(Party).withGuards(IsFriday); // It will only party on fridays
        this.add(Sleep).withHook(GoToHome); // Try to avoid sleeping at the office or the pub
    }
}

@injectable()
class IsFriday implements IGuard {
    public approve():boolean {
        return (new Date()).getDay() === 5;
    }
}

@injectable()
class GoToHome implements IHook {
    @inject(Person)
    public me: Person;

    public hook():void {
        this.me.goHome();
    }
}

Using Payloads

Payloads are used to temporary inject some data, which would not be available otherwise, and make it available to the subcommand, it's guards and it's hooks.

You can pass the data to be injected directly to the withPayloads() method, for a normal injection.

import { inject, injectable, ICommand } from "@robotlegsjs/core";

import { SequenceMacro } from "@robotlegsjs/macrobot";

@injectable()
export class Macro extends SequenceMacro {
    public prepare() {
        const data: SomeModel = new SomeModel();

        this.add(Action).withPayloads(data);
    }
}

@injectable()
class Action implements ICommand {

    @inject(SomeModel)
    public data: SomeModel;

    public execute():void {
        this.data.property = "value";
    }
}

Or you can use the SubCommandPayload class to create a more complex injection.

import { inject, injectable, ICommand } from "@robotlegsjs/core";

import { SequenceMacro, SubCommandPayload } from "@robotlegsjs/macrobot";

@injectable()
export class Macro extends SequenceMacro {

    public prepare() {
        const data: SomeModel = new SomeModel();
        const payload: SubCommandPayload = new SubCommandPayload(data);

        payload.
            .withName("mydata")
            .ofType(IModel);

        this.add(Action).withPayloads(payload);
	}
}

@injectable()
class Action implements ICommand {
    @inject(IModel) @named("mydata")
    public data: IModel;

    public function execute():void {
        this.data.property = "value";
	}
}

Asynchronous commands

While Macrobot can work with synchronous commands, it is most effective when you have to deal with asynchronous ones. Your sub command may wait for a response from a server or for user interaction before being marked as complete. In this case you command can subclass Macrobot's AsyncCommand and call dispatchComplete() when it should be marked as complete. dispatchComplete() receives a single parameter which reports whether the subcommand completed successfully.

Here's an example of a simulated asynchronous sub command:

import { injectable, inject } from "@robotlegsjs/core";

import { AsyncCommand, SequenceMacro } from "@robotlegsjs/macrobot";

@injectable()
export class DelayCommand extends AsyncCommand {
    @inject(Number)
    protected _delay: number;

    public execute(): void {
        setTimeout(this.onTimeout.bind(this), this._delay);
    }

    protected onTimeout(): void {
        this.dispatchComplete(true);
    }
}

@injectable()
export class MyMacro extends SequenceMacro {

    public prepare():void {
        this.add(DelayCommand).withPayloads(50);
        this.add(DelayCommand).withPayloads(100);

        this.registerCompleteCallback(this.onComplete.bind(this));
    }

    protected onComplete(success): void {
        console.log("All commands have been executed!");
    }
}

Atomic execution

For sequential macros, when the atomic property is set to false (it is true by default) and one of the sub commands dispatches a failure (using dispatchComplete(false)), subsequent sub commands will not be executed and the macro itself will dispatch failure.

Here's an example of a non atomic sequence:

import { injectable, inject } from "@robotlegsjs/core";

import { SequenceMacro, AsyncCommand } from "@robotlegsjs/macrobot";

@injectable()
export class NonAtomicSequenceCommand extends SequenceMacro {
    public prepare(): void {
        this.atomic = false;

        this.add(DelayAsyncCommand).withPayloads(25, true);
        this.add(DelayAsyncCommand).withPayloads(50, false);
        this.add(DelayAsyncCommand).withPayloads(750, false);
        this.add(DelayAsyncCommand).withPayloads(100, false);
    }
}

@injectable()
class DelayAsyncCommand extends AsyncCommand {
    @inject(Number)
    protected _delay: number;

    @inject(Boolean)
    protected _succeed: boolean;

    public execute(): void {
        setTimeout(this.onTimeout.bind(this), this._delay);
    }

    protected onTimeout(): void {
        this.dispatchComplete(this._succeed);
    }
}

In the example above, the DelayAsyncCommand will be executed only two times, since the second execution will report a failure and all remaining mappings will be ignored.

This behaviour does not apply to parallel commands.

Macro Command Triggers

Macro commands can be triggered by Events or Signals. In both cases, it is common to have to send payloads to the macro command or sub-commands through the Event or Signal trigger.

The macro command can capture the CommandPayload provided by the CommandExecutor and map it into the context of the sub-commands.

Events

The Event class from @robotlegsjs/core package can send parameters through the optional data property. In more complex cases, you can create your own CustomEvent class that extends the Event class, adding as many payloads as you wish.

When dispatching an event, the IEventCommandMap will map the triggered Event into the context of the macro command, allowing you to access it from inside the macro, from inside guards and hooks or even from inside the context of each sub-command.

Here's an example of a macro command that will load all the assets for your application based on the options of each user. In this case, the user can disable the sound system through user options. When loading the assets, you don't need to load the sound files when the muted option is enabled.

import { inject, IEventCommandMap, IEventDispatcher } from "@robotlegsjs/core";

import { LoadAssetsMacro } from "./commands/LoadAssetsMacro";

import { AssetsEvent } from "./events/AssetsEvent";

export class LoadAssets {
    @inject(IEventCommandMap)
    protected _eventCommandMap: IEventCommandMap;

    @inject(IEventDispatcher)
    protected _eventDispatcher: IEventDispatcher;

    public loadAssets(): void {
        this._eventCommandMap.map(AssetsEvent.LOAD_ASSETS, AssetsEvent).toCommand(LoadAssetsMacro);

        let assetsEvent: AssetsEvent = new AssetsEvent(AssetsEvent.LOAD_ASSETS);
        assetsEvent.muted = false;

        this._eventDispatcher.dispatchEvent(assetsEvent);
    }
}

Since the AssetsEvent will be mapped into the context of the macro command, you can use it on a Guard that can allow the execution of the LoadSoundsCommand only when the sound system is not muted:

import { inject, injectable } from "@robotlegsjs/core";

import { ParallelMacro } from "@robotlegsjs/macrobot";

import { LoadDataCommand } from "./commands/LoadDataCommand";
import { LoadSpriteSheetsCommand } from "./commands/LoadSpriteSheetsCommand";
import { LoadSoundsCommand } from "./commands/LoadSoundsCommand";

@injectable()
export class LoadAssetsMacro extends ParallelMacro {
    public prepare(): void {
        // load data for all users
        this.add(LoadDataCommand);

        // load sprite sheets for all users
        this.add(LoadSpriteSheetsCommand);

        // load sounds only for users who enabled sound system
        this.add(LoadSoundsCommand).withGuards(NotMuted);
    }
}

@injectable()
class NotMuted implements IGuard {
    @inject(AssetsEvent)
    protected _assetsEvent: AssetsEvent;

    public approve():boolean {
        return !_assetsEvent.muted;
    }
}

Signals

The Signal class from @robotlegsjs/signals package can be extended to send parameters through the dispatch trigger.

When dispatching an signal, the ISignalCommandMap from @robotlegsjs/signalcommandmap package will map the payloads into the context of the macro command, allowing you to access them from inside the macro, from inside guards and hooks or even from inside the context of each sub-command.

Here's an example of a macro command that will load all the assets for your application based on the options of each user. In this case, the user can disable the sound system through user options. When loading the assets, you don't need to load the sound files when the muted option is enabled.

The AssetsSignal extends the Signal class adding an Boolean as payload:

import { injectable } from "@robotlegsjs/core";

import { Signal } from "@robotlegsjs/signals";

@injectable()
export class AssetsSignal extends Signal {
    constructor() {
        super(Boolean);
    }
}

Then you can map the AssetsSignal to the LoadAssetsMacro command using the ISignalCommandMap extension:

import { inject, IInjector } from "@robotlegsjs/core";

import { ISignalCommandMap } from "@robotlegsjs/signalcommandmap";

import { LoadAssetsMacro } from "./commands/LoadAssetsMacro";

import { AssetsSignal } from "./signals/AssetsSignal";

export class LoadAssets {
    @inject(IInjector)
    protected _injector: IInjector;

    @inject(ISignalCommandMap)
    protected _signalCommandMap: ISignalCommandMap;

    public loadAssets(): void {
        this._signalCommandMap.map(AssetsSignal).toCommand(LoadAssetsMacro);

        let assetsSignal: AssetsSignal = this._injector.get(AssetsSignal);

        // dispatch the signal telling the macro command that the muted option is disabled
        assetsSignal.dispatch(false);
    }
}

Since the payload of the AssetsSignal will be mapped into the context of the macro command, you can use it on a Guard that can allow the execution of the LoadSoundsCommand only when the sound system is not muted:

import { inject, injectable } from "@robotlegsjs/core";

import { ParallelMacro } from "@robotlegsjs/macrobot";

import { LoadDataCommand } from "./commands/LoadDataCommand";
import { LoadSpriteSheetsCommand } from "./commands/LoadSpriteSheetsCommand";
import { LoadSoundsCommand } from "./commands/LoadSoundsCommand";

@injectable()
export class LoadAssetsMacro extends ParallelMacro {
    public prepare(): void {
        // load data for all users
        this.add(LoadDataCommand);

        // load sprite sheets for all users
        this.add(LoadSpriteSheetsCommand);

        // load sounds only for users who enabled sound system
        this.add(LoadSoundsCommand).withGuards(NotMuted);
    }
}

@injectable()
class NotMuted implements IGuard {
    @inject(Boolean)
    protected _muted: Boolean;

    public approve():boolean {
        return !this._muted;
    }
}

Contributing

If you want to contribute to the project refer to the contributing document for guidelines.

RobotlegsJS Macrobot for enterprise

Available as part of the Tidelift Subscription

The maintainers of @robotlegsjs/macrobot and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.

License

MIT