WIP: Lev 7.0

[joemsak]

• Adds outputs option which must declare all outputs and their sources

class MyRoutine
  lev_routine outputs: { title: :_self,
                         description: { name: DescriptionRoutine, as: :desc }
                         _verbatim: [SubRoutine, :totally_exists, { name: OtherSub, as: :other }] }
end

• Adds a set function which sets the attributes mentioned in the outputs map

class MyRoutine
  lev_routine outputs: { title: :_self }

  def exec
    set(title: 'Hello, world')
  end
end

result = MyRoutine.call
result.title #=> 'Hello, world'

• When you use run it sets all mapped attributes automatically

class OtherSub
  lev_routine outputs: { description: :_self }

  def exec
    set(description: 'Wow a description')
  end
end

class SubRoutine
  lev_routine outputs: { title: :_self, description: OtherSub }

  def exec
    set(title: 'Hello world')
    run(:other_sub)
  end
end

class MyRoutine
  lev_routine outputs: { _verbatim: { name: SubRoutine, as: :sub } }

  def exec
    run(:sub)
  end
end

result = MyRoutine.call

result.title #=> 'Hello world'
result.description #=> 'Wow a description'

[Dantemss]

Currently lev's fatal_error won't actually rollback the DB state if the lev routine is called from inside a non-lev transaction. We could potentially either use requires_new: true when creating the transaction (in which case Lev should rollback its own internal state but not the outer transaction) or, if we want to rollback the entire thing, have Lev raise its own class of rollback error and/or maybe monkeypatch ActiveRecord::Transaction to rollback properly when that error is caught.

[Dantemss]

This is because Lev raises ActiveRecord::Rollback, which is caught and silently ignored by nested transactions: http://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html#module-ActiveRecord::Transactions::ClassMethods-label-Nested+transactions

[Dantemss]

OBE