ActiveRecord, Caching, and the Single Responsibility Principle

"after_* callbacks on Rails models seem to have some of the most tightly-coupled code"

ActiveRecord, Caching, and the Single Responsibility Principle Josh Clayton August 19, 2011 rails good code I was working on a messaging system earlier this week and noticed a pretty tight coupling between two classes. class Message < ActiveRecord::Base belongs_to :author, :class_name => 'User' belongs_to :conversation, :touch => true after_create :author_reads_conversation after_save :update_answered after_save :update_last_student_posted_at after_save :update_last_post_at after_save :update_participants after_save :update_messages_count # ... private def update_answered if conversation.kind == Conversation::QUESTION || conversation.kind == Conversation::ASSIGNMENT if author.instructor? conversation.update_attribute(:answered, true) else conversation.update_attribute(:answered, false) end end end def update_last_post_at conversation.update_attribute(:last_post_at, self.cr...

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