Class: ActiveRecordSurvey::Node

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/active_record_survey/node.rb

Direct Known Subclasses

Answer, Question

Defined Under Namespace

Classes: Answer, Question

Instance Method Summary collapse

Instance Method Details

#answers ⇒ Object

All the answer nodes that follow from this node



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# File 'lib/active_record_survey/node.rb', line 12

def answers
	self.survey.node_maps.select { |i|
		i.node == self
	}.collect { |i|
		# Get all the children from this node
		i.children
	}.flatten.collect { |i|
		# Get the nodes
		i.node
	}.select { |i|
		# Only the nodes that are answers
		i.class.ancestors.include?(::ActiveRecordSurvey::Node::Answer)
	}.uniq.collect { |i|
		i.survey = self.survey # ensure that the survey being referenced by the answers is the original survey - needed for keeping consistent node_maps between build_link and remove_link
		[i] + i.answers
	}.flatten.uniq
end

#build_link(to_node) ⇒ Object

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.rb', line 150

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.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 node 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

#has_instance_node_for_instance?(instance) ⇒ Boolean

Whether this node has an answer recorded the instance

Returns:

  • (Boolean) 


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# File 'lib/active_record_survey/node.rb', line 38

def has_instance_node_for_instance?(instance)
	!self.instance_node_for_instance(instance).nil?
end

#instance_node_for_instance(instance) ⇒ Object

The instance_node recorded for the passed instance for this node



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# File 'lib/active_record_survey/node.rb', line 31

def instance_node_for_instance(instance)
	instance.instance_nodes.select { |instance_node|
		(instance_node.node === self)
	}.first
end

#instance_node_path_to_root?(instance_node) ⇒ Boolean

Whether there is a valid answer path from this node to the root node for the instance

Returns:

  • (Boolean) 


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# File 'lib/active_record_survey/node.rb', line 94

def instance_node_path_to_root?(instance_node)
	instance_nodes = instance_node.instance.instance_nodes.select { |i| i.node === self }

	# if ::ActiveRecordSurvey::Node::Answer but no votes, not a valid path
	if self.class.ancestors.include?(::ActiveRecordSurvey::Node::Answer) &&
		(instance_nodes.length === 0)
		return false
	end

	# Start at each node_map of this node
	# Find the parent node ma
	paths = self.survey.node_maps.select { |i| i.node == self }.collect { |node_map|
		# There is another level to traverse
		if node_map.parent
			node_map.parent.node.instance_node_path_to_root?(instance_node)
		# This is the root node - we made it!
		else
			true
		end
	}

	# If recursion reports back to have at least one valid path to root
	paths.include?(true)
end

#is_answered_for_instance?(instance) ⇒ Boolean

Whether considered answered for instance

Is answered is a little different than has_answer Is answered is answer type specific, as what constitutes “answered” changes depending on the question type asked (e.g. boolean is answered if “1”)

Each specific answer type should override this method if they have special criteria for answered

default - if instance node exists, answered

Returns:

  • (Boolean) 


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# File 'lib/active_record_survey/node.rb', line 51

def is_answered_for_instance?(instance)
	self.has_instance_node_for_instance?(instance)
end

#remove_link ⇒ Object

Removes the node_map link



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# File 'lib/active_record_survey/node.rb', line 120

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_instance_node(instance_node) ⇒ Object

Run all validations applied to this node



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# File 'lib/active_record_survey/node.rb', line 68

def validate_instance_node(instance_node)
	# Basically this cache is messed up? Why? TODO.
	# Reloading in the spec seems to fix this... but... this could be a booby trap for others
	#self.node_validations(true)

	# Check the validations on this node against the instance_node
	validations_passed = !self.node_validations.collect { |node_validation|
		node_validation.validate_instance_node(instance_node, self)
	}.include?(false)

	# More complex....
	# Recureses to the parent node to check
	# This is to validate Node::Question since they don't have instance_nodes directly to validate them
	parent_validations_passed = !self.survey.node_maps.select { |i| i.node == self}.collect { |node_map|
		if node_map.parent
			node_map.parent.node.validate_parent_instance_node(instance_node, self)
		# Hit top node
		else
			true
		end
	}.include?(false)

	validations_passed && parent_validations_passed
end

#validate_parent_instance_node(instance_node, child_node) ⇒ Object

Default behaviour is to recurse up the chain (goal is to hit a question node)



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# File 'lib/active_record_survey/node.rb', line 56

def validate_parent_instance_node(instance_node, child_node)
	!self.survey.node_maps.select { |i| i.node == self}.collect { |node_map|
		if node_map.parent
			node_map.parent.node.validate_parent_instance_node(instance_node, self)
		# Hit top node
		else
			true
		end
	}.include?(false)
end