Ruby: more readable way to write nested if conditions? [closed] - ruby-on-rails

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Is there a more readable way in Ruby (or using Rails model helpers) to write the following:
def get_question
if self.is_question?
self.trackable
elsif self.is_answer?
self.trackable.question
elsif self.is_comment?
if self.trackable.is_question?
self.trackable.commentable
elsif self.trackable.is_answer?
self.trackable.commentable.question
end
end
end
There must be a more "Ruby way" of writing this so it's easier to read for other developers.

Answer 1

I tend to write that sort of thing like this:
def get_question
return self.trackable if self.is_question?
return self.trackable.question if self.is_answer?
return nil if !self.is_comment?
return self.trackable.commentable if self.trackable.is_question?
return self.trackable.commentable.question if self.trackable.is_answer?
return nil
end
that's pretty mu-idiomatic but I don't know if it qualifies as Ruby-idiomatic. Yes, there's an unnecessary return at the end but I like the symmetry and how it makes everything visually line up.
In real life, I'd probably want replace all that logic with a question method on the self.trackable. Then each thing could implement question (or to_question, get_question, or whatever name made the most sense in the broader context):
# Inside questions...
def question
self
end
# Inside answers...
# Nothing special needed, we've already got one.
and so on for the other possible possible self.trackable things. That would leave your get_question looking like this:
def get_question
self.trackable.respond_to?(:question) ? self.trackable.question : nil
end
or you could do away with get_question completely if you knew that self.trackable would also respond to question.