Get absolute position (from 0,0) for a SVG element

svgGetAbsolutePosition.coffee

# Find the position of a SVG DOM element
getPosition = (element) ->
	
	# We have a transform, that might contain a translate(x,y)
	transform = element.getAttribute('transform')
	if transform?
		match = transform.match(/translate\(\s*(-?[\d.]*)\s*[,]\s*(-?[\d.]*)\s*/)
	
	# We have translate(x,y)	
	if match?.length >= 2
		x = parseFloat(match[1])
		y = parseFloat(match[2])
		
	# We try to get x="" and y=""
	else
		x = element.getAttribute('x')
		y = element.getAttribute('y')
	
	# Set x and y to 0 if they are undefined or null
	x ?= 0
	y ?= 0
	
	return {x:x, y:y}

# Find absolute position of a SVG DOM element
findAbsolutePosition = (element) ->
	abspos = {x:0,y:0}
	
	# While we have DOM elements, get position and go to parent
	while(element.getAttribute?)
		pos = getPosition(element)

		if pos and typeof pos.x is 'number'
			abspos.x+=pos.x
			abspos.y+=pos.y

		element = element.parentNode

	return abspos