[This is not an issue per se, rather a question] How to pass in positional arguments, and no keyword arguments?

[alfuken]

How to pass in positional arguments, and no keyword arguments? And at the same time keep the input validation, i.e. input :user, type: User. Is that possible to do here? And, preferably, painlessly. :)

[sunny]

Hi @alfuken! No, positional arguments are not possible on actors.

One way you could make it work for your use-case would be to create a new class method that turns positional arguments into named arguments.

E.g.:

class Pay < Actor
  input :user, type: User

  def self.trigger(user)
    call(user: user)
  end

  # Or even
  def self.call(user)
    super(user: user)
  end

  def call
    puts "Paying #{user.id}…"
  end
end

Pay.trigger(User.first)
# => Paying 32…
Pay.call(User.first)
# => Paying 32…

[alfuken]

The use-case itself is about dynamic steps composition:

conveyor = Conveyor.find(x)
result = conveyor.steps.split(',').map(&:constantize).reduce(&:>>).(JSON.parse(conveyor.input))

Currently steps are just PORO, but the input validation is really something that could be improved, hence Actor :)

self.call with super is actually a good example, and it solves the question. Thanks! 👍

PS. Would be nice to see this in a readme too, in some kind of FAQ or smth, in case someone else has a similar question.

[sunny]

Good idea. As a first step I’ve started a wiki with a link pointing to this issue/question :)