Flowly

A lightweight workflow library.

Workflow creation

You will need to define/extend a workflow somewhere with an initial task, an ExecutionContextFactory, and a repository.

new Workflow {
    override def initialTask: Task = firstTask
    override val executionContextFactory: ExecutionContextFactory = new ExecutionContextFactory(serializer)
    override val repository: Repository = new InMemoryRepository
}

InMemoryRepository is for testing purpose only, but Flowly provides MongoDBRepository implementation to store real workflows.

override val repository: Repository = 
    new MongoDBRepository(
        client = new MongoClient("localhost"),
        databaseName = "flowly-hello-world",
        collectionName = "flows",
        objectMapper = objectMapperContext
    )

Furthermore, you will need an objectMapper that you can construct with Jackson library(provided with flowly) to create then your ExecutionContextFactory

lazy val objectMapperContext = new ObjectMapper with ScalaObjectMapper
objectMapperContext.registerModule(new DefaultScalaModule)
objectMapperContext.registerModule(new JavaTimeModule)
objectMapperContext.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
objectMapperContext.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false)

override val executionContextFactory: ExecutionContextFactory = new ExecutionContextFactory(new JacksonSerializer(objectMapperContext))

Finally, you have to define your initialTask.

override def initialTask: Task = new MyFirstTask(new SecondTask(new ThirdTask(FinishTask("OK"))))

Basic Tasks

//TODO

Execution task

Blocking task

Disjunction task

Composable Tasks

You can't create these tasks without mixing with Basic tasks. They provide retry, cancel, and Skippable behaviors for tasks.

//TODO: Alternative, Condition, Dependencies

Retryable task

//TODO

Scheduling and Stopping strategies

//TODO

Cancellable task

You can make your task 'cancellable' by mixing Cancellable trait.

Then call cancel workflow method with sessionId(will fail if current task does not support cancellation)

You can also define task to run when the cancellation process starts by overriding followedByAfterCancel method. Take care with your last task, It should be CancelTask like in base method.

Alternative

//TODO

Condition

//TODO

Dependencies

//TODO