An unopinionated flow oriented blackbox designer, executor and debugger to interface your service classes and allow users to manipulate or completely redesign processes using your code.

Add this line to your application's Gemfile:

gem 'caixanegra'

or

bundler add caixanegra

caixanegra implements a self-contained flow designer and executor.
To get started, the only thing you need is to point to your transient store implementation and point out which classes on your codebase should represent units.

First, mount the engine. Add the line below to routes.rb file:

mount Caixanegra::Engine, at: "/caixanegra", as: :caixanegra

Then, let's create a caixanegra.rb initializer (or any name you prefer)

Caixanegra.setup do |config|
  config.units = [
    Caixanegra::Units::AwesomeUnit,
    Some::Other::Namespace::AnotherAwesomeUnit,
    [Caixanegra::Units::NamespaceOne::SuperUnit, :ns1_super_unit],
    [Caixanegra::Units::NamespaceTwo::SuperUnit, :ns2_super_unit],
  ]
  config.transient_store = GreatTransientStore.new
end

While configuring units from your codebase, if provided in the array form, caixanegra will use the second array item as the class name. Otherwise it will infer from class.
NOTE: You can't have two classes with the same name as caixanegra will use the last one

With the designer configured, you can use Caixanegra::Manager to handle the previously stored definition (or an empty one).
This will give you the UID that caixanegra designer will understand, using transient store.

my_flow = somewhere.get_flow # get from your own persistence or transport solution
uid = Caixanegra::Manager.handler(flow_definition: my_flow || {})

You can then safely navigate to the designer.

link_to "Some flow", "/caixanegra/design/#{@uid}?unit_scope=optional_scope,another_optional_scope", target: :_blank

Saved changes will update the flow definition through the transient store, and you must then persist them. You can get the flow definition for any specified caixanegra handled UID, given that the transient store is able to correctly sort them out:

updated_flow = Caixanegra::Manager.get(my_uid)
persist_flow(updated_flow) # your own persistence or transport solution. It's a JSON

Please, refer to the wiki to get to know more about units.

caixanegra is available as open source under the terms of the MIT License.