Registers system wide services.

Each service/2 macro registers system-wide service and function with documentation in module that uses this module.

servicep/2 is considered as private service and is not introduced to other nodes in the cluster.

Service functions invoke function of the same name of specified module. If result of that invocation is {:reply, %X3m.System.Message{}}, it sends message to message.reply_to pid.

If result of invocation is :noreply, nothing is sent to that pid.

In any case function returns :ok.

Examples

Defining router

defmodule MyRouter do
  use X3m.System.Router

  @servicedoc false
  service :create_user, MessageHandler

  @servicedoc """
  overridden!
  """
  service :get_user, MessageHandler

  service :edit_user, MessageHandler

  servicep :private_service, MessageHandler
end

When defining a router you can pass :ensure_local_logging? argument in options which is expected to be boolean(). This argument is optional and if not passed is treated as true thus ensuring logs of the called node are not shown on the calling node.

When this argument is passed as false, log messages sent to stdout by the called node will be shown in the caller node stdout, thus keeping REPL behaviour is maintained.

Examples

Defining router ensuring remote callers don't receive logger stdout

defmodule MyRouter do
  use X3m.System.Router

  ...
end

is identical to

defmodule MyRouter do
  use X3m.System.Router

  ...
end

Defining router with default logger behaviour

defmodule MyRouter do
  use X3m.System.Router, ensure_local_logging?: false

  ...
end

Getting registered services (public, private, or by default all)

iex> MyRouter.registered_services()
[create_user: 1, get_user: 1, edit_user: 1, private_service: 1]

iex> MyRouter.registered_services(:public)
[create_user: 1, get_user: 1, edit_user: 1]

Invoking service as a function

iex> :create_user |>
...>   X3m.System.Message.new() |>
...>   MyRouter.create_user()
:ok