Identify which action is being called inside a model. Ruby on Rails

问题

How do I come to know whether a create or any other action has been called from inside a model. Basically I am doing database logging and want to track whether a create or other actions are being performed.

For doing the logging part I am using the concept of ActiveRecord::Observer. But there I am not able to find out whether the user is creating or doing something else. So please tell me some way that rails provides us to identify the action inside the model.

thanks in advance.

回答1:

You can use a before_save to trigger an event when the model is saved. To determine if it is a save or a create you have this method new_record? which will tell you if it's a new instance or not. You can also know which attributes have changed

回答2:

Such this kind of tracking should be performed on the Controller. Observers are only model-aware and should be model-aware only.

Consider the case where you are updating the object from the console. The observer will be triggered, but you have no request context here.

回答3:

Which ever action is called in application is stored in params[:action] and params is not accessible in models. So i don't think you can see which action is getting called from models.

Thanks,Anubhaw

回答4:

This is not recommended from architectural point of view but this is used only for low level logging deep inside Model and doesn't do any harm. Also this is thread-safe solution.

ApplicationController or just single controller:

around_filter :store_remote_ip_in_thread

def store_remote_ip_in_thread
  begin
    Thread.current[:remote_ip] = request.remote_ip
    yield
  ensure
    Thread.current.delete :remote_ip
  end
end

Reusable module for retrieval:

module RemoteIpAware
  def current_remote_ip
    Thread.current[:remote_ip] || '-'
  end
end

Somewhere in model/mailer/lib class:

 include RemoteIpAware
 ...
 #use current_remote_ip method anywhere

Keep in mind I wrote it from my memory.. syntax may not be ok ;) In you case instead of remote IP you can save params[:action] :controller name etc..

来源：https://stackoverflow.com/questions/3726136/identify-which-action-is-being-called-inside-a-model-ruby-on-rails

标签

ruby-on-rails

ruby

model

action