prediction description change description ignores who made the change

[roryokane]

ArisKatsaris described the problem at http://lesswrong.com/r/discussion/lw/bl4/harry_potter_and_the_methods_of_rationality/6a8w. Ey says that the problem is on http://predictionbook.com/predictions/3237: one of the list items says

• ArisKatsaris changed their prediction from “In “Harry Potter and the Methods of Rationality” it will be revealed that Voldemort never intended Harry’s own death on the night of his parents’ death.” 3 days ago

, but apparently gwern was the user who actually made that change. The template always says that it was the creator of the prediction who changed the description, whether that is true or not.

Here are some files I found that are relevant to fixing this:

• app/views/predictions/versions/_event.html.erb
  • This is where the user is printed. <%= show_user(event.prediction.creator) %> always displays the creator of the prediction. That part will need to be different if the event in question is a type that can be done by people other than the creator. Changing the description is one such type of event; I don't know if any of the other types are like that.
• app/helpers/version_helper.rb
  • This demonstrates how to tell what type of event an event is. It also lists all of the event types
• app/models/prediction.rb
  • Line 103 shows that events can be a Response, a non-current "version", or a Judgement. Line 2, version_fu, in conjuction with db/schema line 41, suggests that a "version" is just a Prediction with the attributes having old values. A Prediction belongs_to a User, but that is the creator. We may need a different place to store the user who changed a specific version. Perhaps we need to create an actual PredictionChange.