CommandKU

This library is so similar to an event bus or a message queue. The differences are

• For what we called event or message in other libraries here we named them command.
• Commands are in request-result pairs, which means for each request command we have a result
  command.
• No broadcast command, because this library matches the results with requests, which is not
  achievable for broadcasts.

To handle the request-result pairs we used Kotlin coroutines’ biggest power, which is making
callbacks similar to ordinary lines of code with an input and output.

Usage

Let’s have some RequestCommand and ResultCommand like

data class RequestCommand(val request: String) : Command
data class ResultCommand(val result: String) : Command

we want to have a few lines of coroutines code to send the request and receive the result.

suspend fun CommandExecutor.runCommand(request: String): CommandResult<ResultCommand> =
  exe(RequestCommand(request))
scope.launch {
  when (val result = executor.runCommand("Are you there?")) {
    is Available<*> -> assert(result.command == ResultCommand("Yes! Of course!"))
  }
}

There are a few notes here.

• It doesn’t have any thread executor, so the coroutine context of calling exe will be used to
  run all suspend functions.
• As you can see it’s possible that no callback is registered to handle the requested command,
  in that case the is Available<*> branch of when will not be called.

To receive the request and respond to it

val registration = commandRegister.register(RequestCommand::class,
  CommandCallbackImpl(commandShooter) {
    ResultCommand("Yes! Of course!")
  })

whenever is needed we can dispose the registration.

Download

Download via gradle

implementation "com.github.hadilq:command-ku-api:$libVersion"
implementation "com.github.hadilq:command-ku-impl:$libVersion"

where you can find the libVersion in the Releases page of this repository.

Snapshots of the development version are available in Sonatype’s snapshots repository.

Contribution

Create an issue and suggest your idea and raise your hand if you want to implement it. If it’s okay
please create a pull request. Thank you, you’re awesome.