How to create notification system in rails? -

basically, want create notification facebook , stackoverflow. specifically, in post-comments system, when post commented, involved (people creates post , create comments, except new commenter) gets notification message post commented. , notification dismissed when people have read it.

i have tried use mailboxer gem implement it, saddly there no example available using related methods, including social_stream itself.

is there other way create notification system?

and when try create scratch several problems:

    model notification     topic_id: integer     user_id: integer     checked: boolean #so can tell whether notification read or not 

1. dismissing notication after being read users

i think need turn every notification messages' "checked" attribute true after user visit index of notification.(in notificationscontroller)

    def index       @notifications=current_user.notication.all       @notification.each |notification|          notification.checked = true       end       @notification.save!     end 

2.selecting users notify(and exclude user making new comment)

i have no idea in wrting queries....

3.creating notifications

i think should like

    #in commentcontroller     def create       #after creating comments, creat notifications       @users.each |user|         notification.create(topic_id:@topic, user_id: user.id)       end     end 

but think ugly

there no need anwer 3 problems above, simple solution notification system preferable , thanks....

i think on right path.

a better notifications#index

def index   @notifications = current_user.notications   @notifications.update_all checked: true end 

2. notify users

   user.uniq.joins(:comments).where(comments: {id: @comment.post.comment_ids}).reject {|user| user == current_user } 

unique users participated in @comment's post comments, reject (remove result) current_user.

3. an observer pointed out joão daniel, preferred on after_create. "rails best practice" describes pretty well: http://rails-bestpractices.com/posts/2010/07/24/use-observer