try this
has_and_belongs_to_many :posts, after_add: [:method1, :method2]
Question
How can we have two methods for after_add callback on mongoid relations. Both the methods need to do different things?
has_and_belongs_to_many :posts, after_add: method1, after_add: method2
Solution
try this
has_and_belongs_to_many :posts, after_add: [:method1, :method2]