Class: ActiveRecordSurvey::Node::Answer

Inherits:
ActiveRecordSurvey::Node show all
Defined in:
lib/active_record_survey/node/answer.rb

Direct Known Subclasses

Boolean, Rank, Scale, Text

Defined Under Namespace

Classes: Boolean, Rank, Scale, Text

Instance Method Summary collapse

Methods inherited from ActiveRecordSurvey::Node

#answers, #has_instance_node_for_instance?, #instance_node_for_instance, #instance_node_path_to_root?, #is_answered_for_instance?, #validate_instance_node, #validate_parent_instance_node

Instance Method Details

Build a link from this node to another node Building a link actually needs to throw off a whole new clone of all children nodes



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# File 'lib/active_record_survey/node/answer.rb', line 84

def build_link(to_node)
  # build_link only accepts a to_node that inherits from Question
  if !to_node.class.ancestors.include?(::ActiveRecordSurvey::Node::Question)
    raise ArgumentError.new "to_node must inherit from ::ActiveRecordSurvey::Node::Question"
  end

  if self.question.nil?
    raise ArgumentError.new "A question is required before calling #build_link"
  end

  if self.survey.nil?
    raise ArgumentError.new "A survey is required before calling #build_link"
  end

  from_node_maps = self.survey.node_maps.select { |i| i.node == self && !i.marked_for_destruction? }

  # Answer has already got a question - throw error
  if from_node_maps.select { |i|
    i.children.length === 0
  }.length === 0
    raise RuntimeError.new "This answer has already been linked" 
  end

  # Because we need something to clone - filter this further below
  to_node_maps = self.survey.node_maps.select { |i| i.node == to_node && !i.marked_for_destruction? }

  if to_node_maps.first.nil?
    to_node_maps << self.survey.node_maps.build(:survey => self.survey, :node => to_node)
  end

  # Ensure we can through each possible path of getting to this answer
  to_node_map = to_node_maps.first
  to_node_map.survey = self.survey # required due to voodoo - we want to use the same survey with the same object_id

  # We only want node maps that aren't linked somewhere
  to_node_maps = to_node_maps.select { |i| i.parent.nil? }
  while to_node_maps.length < from_node_maps.length do
    to_node_maps.push(to_node_map.recursive_clone)
  end

  # Link unused node_maps to the new parents
  from_node_maps.each_with_index { |from_node_map, index|
    from_node_map.children << to_node_maps[index]
  }

  # Ensure no infinite loops were created
  from_node_maps.each { |node_map|
    # There is a path from Q -> A that is a loop
    if node_map.has_infinite_loop?
      raise RuntimeError.new "Infinite loop detected"
    end
  }
end

#next_question ⇒ Object

Returns the question that follows this answer



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# File 'lib/active_record_survey/node/answer.rb', line 34

def next_question
  self.survey.node_maps.select { |i|
    i.node == self && !i.marked_for_destruction?
  }.each { |answer_node_map|
    answer_node_map.children.each { |child|
      if !child.node.nil? && !child.marked_for_destruction?
        if child.node.class.ancestors.include?(::ActiveRecordSurvey::Node::Question)
          return child.node
        elsif child.node.class.ancestors.include?(::ActiveRecordSurvey::Node::Answer)
          return child.node.next_question 
        end
      else
        return nil
      end
    }
  }
  return nil
end

#question ⇒ Object

Returns the question that preceeds this answer



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# File 'lib/active_record_survey/node/answer.rb', line 15

def question
  self.survey.node_maps.select { |i|
    i.node == self
  }.collect { |node_map|
    if node_map.parent && node_map.parent.node
      # Question is not the next parent - recurse!
      if node_map.parent.node.class.ancestors.include?(::ActiveRecordSurvey::Node::Answer)
        node_map.parent.node.question
      else
        node_map.parent.node
      end
    # Root already
    else
      nil
    end
  }.first
end

#remove_link ⇒ Object

Removes the link



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# File 'lib/active_record_survey/node/answer.rb', line 54

def remove_link
  # not linked to a question - nothing to remove!
  return true if (question = self.next_question).nil?

  count = 0
  to_remove = []
  self.survey.node_maps.each { |node_map|
    if node_map.node == question
      if count > 0
        to_remove.concat(node_map.self_and_descendants)
      else
        node_map.parent = nil
      end
      count = count + 1
    end

    if node_map.node == self
      node_map.children = []
    end
  }
  self.survey.node_maps.each { |node_map|
    if to_remove.include?(node_map)
      node_map.parent = nil
      node_map.mark_for_destruction
    end
  }
end

#validate_node(instance) ⇒ Object

Answer nodes are valid if their questions are valid! Validate this node against an instance



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# File 'lib/active_record_survey/node/answer.rb', line 5

def validate_node(instance)
  # Ensure each parent node to this node (the goal here is to hit a question node) is valid
  !self.survey.node_maps.select { |i|
    i.node == self
  }.collect { |node_map|
    node_map.parent.node.validate_node(instance)
  }.include?(false)
end