gistfile1.rb

module PiProcessing
  class TaskInitializer

    attr_accessor :result

    def initialize(flow, shared_context, tokens)
      @flow = flow
      @shared_context = shared_context
      @dependency_manager = DependencyManager.new(tokens)
    end

    def create(assignment: nil)
      shared_context = @shared_context
      dependencies = @dependency_manager

      if assignment
        root = dependencies.by_name(assignment.reference).first
      end

      result = @result = PiProcessing::ProcessingResult.new({}, dependencies: dependencies)

      @flow.task(declares: [ root ]) do
        tokens = assignment && dependencies.get(assignment.calculation_dependencies) || dependencies.all

        dep_vars = [*import(*tokens)]
        result.save(tokens.zip(dep_vars.map(&:value)))

        if assignment
          variable = import root
          variable.value = assignment.calculate result.merge(shared_context)
        end
      end
    end
  end
end