ruby on rails - Is that a proper way to refactor ActiveRecord fat models? -

if example i've activerecord model:

app/models/order.rb

class order < activerecord::base   # model logic end require "lib/someclass.rb" 

lib/somelass.rb

class order   before_save :something   # more logic here end 

is way refactor/extract logic model? or maybe use concern class, service class or else?

like told me long time ago:

code refactoring not matter of randomly moving code around.

in example doing: moving code file

why bad?

by moving code around this, making original class more complicated since logic randomly split several other classes. of course looks better, less code in 1 file visually better that's all.

prefer composition inheritance. using mixins asking "cleaning" messy room dumping clutter 6 separate junk drawers , slamming them shut. sure, looks cleaner @ surface, junk drawers make harder identify , implement decompositions , extractions necessary clarify domain model.

what should then?

you should ask yourself:

• which code goes , part of new class / module ?
• where makes sense extract code somewhere else ?
• do have piece of code shared across application ?
• can extract recurrent patterns in code base ?

extract service object

i reach service objects when action meets 1 or more of these criteria:

• the action complex
• the action reaches across multiple models
• the action interacts external service
• the action not core concern of underlying model
• there multiple ways of performing action

extract form objects

when multiple model can updated a single form submission, might want create form object.

this enable put form logic (name conventions, validations , on) 1 place.

extract query objects

you should extract complex sql/nosql queries own class. each query object responsible returning result set based on criterias / business rules.

extract presenters / decorators

extract views logic presenters. model should not deal specific views logic. moreover, enable use presenter in multiple views.

more on decorators

thanks this blog post me putting these together.