from zope.interface import Interface

class IContentHistory(Interface):
	"""
	Utility to manage historical entries of a content
	"""
	
	def listEntries() :
		"""
		Return historical entries of the content
		"""
	
	def getHistoricalRevisionByKey(key) :
		"""
		Return the object revision at state targeted by key.
		"""
	
	def compare(leftkey, rightkey) :
		"""
		Return formated comparision of 2 revisions of content
		"""
	
	def restore(key) :
		"""
		Restore the content by editing chosen versionned attributes.
		example: for a Document, only the textual content will be restored.
				 Metadata or talkback stay unchanged.
		"""