soveran / micromachine Goto Github PK

This is by far one of the cleanest code I've ever encountered.
You deserve my LOVE.
❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️ ❤️

it would be useful if one could do

machine.when(:event,:any => :state)

it is especially useful for events like :reset, for example a connection is dropped and everything must begin anew.

Latest release on Rubygems is 2.0.0, which does not include triggerable_events method.
This issue can be easily solved by releasing a new [bumped] version, since the code is already in place.

Ref: https://rubygems.org/gems/micromachine/versions/

It seems to me that bang methods in a state machine model suggests that the change in state will be saved. I think it's better not to use ! in the example code. What do you think?

This is probably a very rare case, but the change in fc9635c is not compatible with the previous version and could result in failures.

The code below demonstrates:

require 'micromachine'

class CallbackBug
  def initialize
    @fsm = MicroMachine.new(:new).tap do |fsm|
      fsm.when(:first,  new: :first_stage)
      fsm.when(:second, first_stage: :second_stage)

      fsm.on(:first_stage, &method(:first_stage))
      fsm.on(:second_stage, &method(:second_stage))

      fsm.on(:any) do |event|
        puts "Event #{event} => #{@fsm.state}"
      end
    end
  end

  def run
    @fsm.trigger!(:first)
    @fsm.trigger!(:second)
  end

  private

  def first_stage(event)
    p event
  end

  def second_stage
  end
end

CallbackBug.new.run

The output of this is:

:first
Event first => first_stage
ArgumentError: wrong number of arguments (1 for 0)
from (pry):28:in `second_stage'

Hello,

I love the simplicity of this library, thank you for creating it!

I am looking for a FSM framework and micormachine is a close match. However, we want to automate some part of our workflow. In order to do that, the object needs to know its available next states it can transition into, all its available events (to transition into the next state) and possibly the previous state.

Here is a code example to better describe this feature:

(irb): machine.state
=> :confirmed
# This is what I'd need
(irb): machine.next_events
=> [:reset]
(irb): machine.next_states
=> [:new]
(irb): machine.previous_states
=> [:new]

I understand this tool is very simple and you might want to keep it simple. I figured I need to build this functionality and others might take advantage of it.

What do you think?

If i run rake or rake test i get:

Warning: you should require 'minitest/autorun' instead.
Warning: or add 'gem "minitest"' before 'require "minitest/autorun"'

and the suite stops with the error

MiniTest::Unit::TestCase is now Minitest::Test. From /Users/xxx/.rbenv/versions/2.1.2/lib/ruby/2.1.0/test/unit/testcase.rb:8:in `<module:Unit>'
/Users/xxx/.rbenv/versions/2.1.2/lib/ruby/2.1.0/test/unit.rb:676:in `<class:Runner>': undefined method `_run_suite' for class `Test::Unit::Runner' (NameError)

I'm on OS X Yosemite (v 10.10) with
ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-darwin13.0]
installed with rbenv

In order to have the test suite working i had to:

rbenv local 1.9.3-p547
gem install contest
rake

Side note: I've tried to use dep install to get contest installed but it failed with:

gem install contest:0.1.3
ERROR:  Could not find a valid gem 'contest:0.1.3' (>= 0) in any repository

Not really used to IRC, so felt like i could ask here; sorry if it does not fit. Plus I'm pretty ne to fsm,
I found this gem very understandable, and somehow not bloated compared to other solutions, so 'id like to go further using it

I have a simple use case; let's say sending a specific mail when a state change for one to another.

So in a controller's action, and compared to the example you provide :

@model = Model.find(params[:id])
@model.confirm!
@model.save # to have the new sate effectively saved

In the model I have this :

...
fsm.on(:confirmed) do
  ... sending some mail ...
end
...

If for some reason the model does not save, the mail is still sent (the fsm.on event occurs right when you call confirm! on it). Is it possible able to fire the vent only if the model is valid to save ?

To keep a simple syntax, only calling .confirm! on the model (not overriding with .save to effectively having the state changed in the db), to validate and save the new state. Is that something possible ?

Again, I know it is not stack overflow; hope I'm clear and that it's okay to ask this kind of thing

Best.

MicroMachine exposes an events method, which lists all events that may be possible at any time. But only a subset of those can be triggered from a given state.

In an application it's sometimes useful to present that subset to users. For instance, if a post is in "draft" status, display buttons to trigger :publish or :archive, but not to :unpublish.

I'm using this code to find triggerable events:

sm.transitions_for.keys.select { |event| sm.trigger?(event) }

Might this be worth adding to MicroMachine itself?