scope
scope :valid_user, -> (user_key, secret_token) { if [user_key, secret_token].all? then where("user_key = ? AND secret_token = ? AND secret_token_expiry >= now()", user_key, secret_token) end }
scope always returns a chainable object
So if you intend to do something like this:
# model
scope :matched_thing, -> { where(...).take }
# invoke
thing = model.matched_thing
# even there is nothing matched, it still returns `ActiveRecord::Relation []`
if thing
this will always be executed
else
#....
end
# take it outside of scope
thing = model.matched_thing.take
# convert [] to nil, ["active_record"] to active record
or
if thing.present?
t = thing.take
# unwrap active record from relation
...
else
...
end