def save(self):
""" Modifies the content of page, creates rev if necessary.
"""
def txn(factsheet, new_content, patch):
r = Revision(parent=factsheet, editor=factsheet.editor, content=patch, number=factsheet.revision_number)
factsheet.content = new_content
factsheet.revision_number += 1
r.put()
factsheet.put()
if self._is_revision:
raise Exception("Cannot save revision.")
if self.content != "" and self.content != self.new_content:
differ = dmp.diff_match_patch()
patch = differ.patch_toText(differ.patch_make(self.new_content, self.content))
db.run_in_transaction(txn, self, self.new_content, patch)
logging.info("Created new revision (%d) for factsheet %s" % (self.revision_number, self.name))
else:
self.content = self.new_content
self.put()
def revision(self, number):
""" Returns a given revision
"""
if self._is_revision:
raise Exception("Cannot get revision of revision.")
differ = dmp.diff_match_patch()
history = Revision.all().ancestor(self)
history.filter("number >=", number).order("-number")
revised_content = self.content
for r in history:
patch = differ.patch_fromText(unicode(r.content))
revised_content = differ.patch_apply(patch, revised_content)[0]
earliest = r
revised_page = self.__class__(
key_name=self.key().name(),
content=revised_content,
editor=earliest.editor,
modified=earliest.created,
number=earliest.number,
is_revision=True,
)
return revised_page
