Question

I’d like to define a default before_save callback for any model that is a MongoMapper model. For example, with ActiveRecord I could just do this in an initializer:

module ActiveRecord
  class Base
    before_save :strip_attrs

    private

    def strip_attrs
      # do stuff
    end
  end
end

Is it possible to do something like this with MongoMapper?

Answer 1

Try building an ActiveSupport::Concern plugin and then plug it into MongoMapper::Document, just like MongoMapper does for its internal plugins.

module StripOnSave
  extend ActiveSupport::Concern

  included do
    before_save :strip_attrs
  end

  def strip_attrs
    # ...
  end
end

module MongoMapper
  module Document
    include StripOnSave
  end

  module EmbeddedDocument
    include StripOnSave
  end
end