Class: Smartdown::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/smartdown/engine.rb,
lib/smartdown/engine/state.rb,
lib/smartdown/engine/errors.rb,
lib/smartdown/engine/transition.rb,
lib/smartdown/engine/interpolator.rb,
lib/smartdown/engine/node_presenter.rb,
lib/smartdown/engine/predicate_evaluator.rb,
lib/smartdown/engine/conditional_resolver.rb

Defined Under Namespace

Classes: ConditionalResolver, IndeterminateNextNode, Interpolator, NodePresenter, PredicateEvaluator, State, Transition, UndefinedValue

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(flow) ⇒ Engine

Returns a new instance of Engine.



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# File 'lib/smartdown/engine.rb', line 9

def initialize(flow)
  @flow = flow
end

Instance Attribute Details

#flow ⇒ Object (readonly)

Returns the value of attribute flow.



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# File 'lib/smartdown/engine.rb', line 7

def flow
  @flow
end

Instance Method Details

#default_predicates ⇒ Object 



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# File 'lib/smartdown/engine.rb', line 21

def default_predicates
  {
    otherwise: ->(_) { true }
  }
end

#default_start_state ⇒ Object 



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# File 'lib/smartdown/engine.rb', line 13

def default_start_state
  Smartdown::Engine::State.new(
    default_predicates.merge(
      current_node: flow.name
    )
  )
end

#evaluate_node(state) ⇒ Object 



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# File 'lib/smartdown/engine.rb', line 49

def evaluate_node(state)
  current_node = flow.node(state.get(:current_node))
  NodePresenter.new.present(current_node, state)
end

#process(responses, start_state = nil) ⇒ Object 



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# File 'lib/smartdown/engine.rb', line 27

def process(responses, start_state = nil)
  state = start_state || default_start_state
  unprocessed_responses = responses
  while !unprocessed_responses.empty? do
    nb_questions = 0
    current_node = flow.node(state.get(:current_node))
    nb_questions += current_node.elements.select{|element|
      element.is_a? Smartdown::Model::Element::MultipleChoice
    }.count

    #There is at least one relevant input per transition for now:
    #Transition from start to first question relies on an input, regardless of its value
    nb_relevant_inputs = [nb_questions, 1].max
    input_array = unprocessed_responses.take(nb_relevant_inputs)
    unprocessed_responses = unprocessed_responses.drop(nb_relevant_inputs)

    transition = Transition.new(state, current_node, input_array)
    state = transition.next_state
  end
  state
end