Trax.Effect.StateMachine 1.57.4

Trax.Effect

Part of Trax: business logic you can call, schedule, or serve as an API, with every run recorded in your Postgres. Docs · Getting started · All repos

Trax.Effect adds run records, dependency injection and storage providers to Trax trains, plus the portable state-machine engine. Its ServiceTrain runs the same chain as a Trax.Core Train, resolves junctions from DI, and writes a metadata row for every run. Trax.Mediator, Trax.Scheduler and the layers above it all run trains through it.

Install

dotnet add package Trax.Effect
dotnet add package Trax.Effect.Data.Postgres   # or Trax.Effect.Data.Sqlite, or Trax.Effect.Data.InMemory

Install one storage package, since runs are recorded only through one: Postgres for production, SQLite for a single process, InMemory for tests.

Example

Adapted from the game server sample:

builder.Services.AddTrax(trax => trax
    .AddEffects(effects => effects
        .UsePostgres(connectionString)
        .SaveTrainParameters()
        .AddJunctionLogger()));

builder.Services.AddScopedTraxRoute<IRecalculateLeaderboardTrain, RecalculateLeaderboardTrain>();

public interface IRecalculateLeaderboardTrain
    : IServiceTrain<RecalculateLeaderboardInput, RecalculateLeaderboardOutput>;

public class RecalculateLeaderboardTrain
    : ServiceTrain<RecalculateLeaderboardInput, RecalculateLeaderboardOutput>,
        IRecalculateLeaderboardTrain
{
    protected override Task<Either<Exception, RecalculateLeaderboardOutput>> Junctions() =>
        Chain<AggregateScoresJunction>()
            .Chain<RankPlayersJunction>()
            .Resolve();
}

public class RankPlayersJunction(ILogger<RankPlayersJunction> logger)
    : Junction<RecalculateLeaderboardInput, RecalculateLeaderboardOutput> { /* ... */ }

Inject IRecalculateLeaderboardTrain and call Run(input). Each run writes a row to trax.metadata: when it started, how it ended, and on failure the junction that threw and its exception. SaveTrainParameters() adds the input and output.

Where this fits

Trax is split into layers, one repo each. Take the ones you need; the trains you wrote do not change. You are here: Trax.Effect.

Docs live in Trax.Docs and are published at traxsharp.net/docs.

Contributing

Read AGENTS.md before changing code. Report vulnerabilities privately as described in SECURITY.md.

License

MIT. There is no commercial edition, and there will not be one.

Trax is an independent open-source project and is not affiliated with the Utah Transit Authority, Trax Retail, or any other organization using the Trax name.