Rails: class methods or scope

[roman-dubrovsky]

Just a question: when should we prefer to use rails scope and where class methods?

These are almost similar things ( one different. That if the lambda (or logic) returns nil, scope returns the current value in this, class method returns nil) See https://www.justinweiss.com/articles/should-you-use-scopes-or-class-methods/

Usually, I use the rule. I prefer to use scope for subqueries, but move it to class methods if it needs to use do end block

# ok
def self.active
  where(finished: false)
end

# better 
scope :active, -> { where(finished: false) }

# bad 
scope :active, -> do 
  where(finished: false) 
    .joins(:statuses)
end

# good 
def self.active
  where(finished: false) 
    .joins(:statuses)
end

Your thoughts?

[TheBlackArroVV]

My thoughts about this, that we should use scope for returning some data. Just use a for many lines

(lambda do |user_id|
  Post.where(user_id: user_id)
end)

But as all situation this has a corner case, i think, which i can't specify

[AleksSenkou]

I like scopes for one line and class methods for 1+ lines

For esthetic and readability purposes

[roman-dubrovsky]

@TheBlackArroVV in fact, there are no big differences between scopes and class methods which returns an ActiveRecord relation. So here I just agree with Aleks that we should avoid using multiline lamda calls for esthetic and readability purposes