Get the dot notation of a embedded Mongoid element

I needed to get the dot notation for embedded documents to perform queries using the given dot notation.

I could not find a "standard" way of doing just that, so here are some helper methods I use in a class. (Part of soon-to-come BoxCMS)

This Gist uses Mongoid metadata and reflect_on_all_associations, so it might break for newer versions of mongoid at some point.

Using dot notation queries in mongoid, makes it easy to dig for even the deepest "weird" embedded structures you might have.

Example of query:
»  Box::Page.where("rows.boxes.box_items.is_template_object" => false).first

Dot notations in mongodb are a powerful tool, but use it wisely unless you are indexing "more than you should".
Basic usage: Call dot_notation_for_element(embedded_element) to get the dot notation all the way up to the parent document, excluding the parent documents name/embedded name.

	#
	# Get dot notification for the current mongoid element
	#
	def dot_notation_for_element(element)
	return "" if element.nil?
	dot_notation = dot_notation_for_element_nested(element)
	if dot_notation.nil?
	return ""
	else
	dot_notation[0] = ''
	end
	dot_notation
	end
	#
	# Get dot notification for nested elements (nesting updwards)
	#
	def dot_notation_for_element_nested(element)
	# Get non-nil_embedded_relation
	p = get_embedded_relation(element)
	# puts p.inspect
	if p.nil?
	return nil
	else
	"#{dot_notation_for_element_nested(p[0])}.#{p[1].inverse_of}"
	end
	end
	#
	# Returns array [p, r], where p is the parent element for the embedded element, and
	# r is the inverse reflection name
	#
	def get_embedded_relation(element)
	element.reflect_on_all_associations(:embedded_in).each do |r|
	# puts r.inspect
	p = element.send(r.name.to_s)
	return [p, r] unless p.nil?
	end
	nil
	end

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