Problem with record not being saved but no errors

rubyonrails-talk
1

I tried to implement a simple model_logger table that is polymorphic as logable. Wanted nothing more than a text field (log) that text is appended to.

The ModelLog model just has a simple set_log method   def set_log(entry)     self.log << "\r\n#{Time.now.to_s} - #{entry}"     self.save     #puts "Model Log Saved #{errors.inspect}"   end

I also have a set_log in the logable model that creates the polymorphic has_one if not there then calls the set_log in ModelLog. Nothing difficult and it all appears to work in the console - commit messages etc, but the above save does not appear to be committed. If I add messages/lines to the record the appear until I get a fresh copy of the record and it only contains the original created entry

I've spent about 6 hours looking at this I am stumped. I added a log message to a show page and it has the same behavior. A message is appended, but each call only shows the original log created message and the last appended.

Below is console log that fetches a record, adds a message, displays the changes, reloads the record and it is gone:

1.9.2-p136 :011 > ml = ModelLog.find(10)   ModelLog Load (0.2ms) SELECT "model_logs".* FROM "model_logs" WHERE "model_logs"."id" = ? LIMIT 1 [["id", 10]] => #<ModelLog id: 10, logable_id: 3, logable_type: "Candidate", log: "2012-11-16 05:26:52 -0600 - Created", created_at: "2012-11-16 11:26:52", updated_at: "2012-11-16 11:26:52"> ##NOTICE ONLY CREATE ENTRY IN log 1.9.2-p136 :012 > ml.set_log("just set and save")    (0.1ms) begin transaction    (0.1ms) commit transaction Model Log Saved #<ActiveModel::Errors:0x000001020e3500 @base=#<ModelLog id: 10, logable_id: 3, logable_type: "Candidate", log: "2012-11-16 05:26:52 -0600 - Created\n2012-11-16 05:5...", created_at: "2012-11-16 11:26:52", updated_at: "2012-11-16 11:26:52">, @messages={}> => nil 1.9.2-p136 :013 > ml => #<ModelLog id: 10, logable_id: 3, logable_type: "Candidate", log: "2012-11-16 05:26:52 -0600 - Created\n2012-11-16 05:5...", created_at: "2012-11-16 11:26:52", updated_at: "2012-11-16 11:26:52"> ##NOTICE CREATE ENTRY AND APPENDED ENTRY in log

1.9.2-p136 :014 > ml = ModelLog.find(10)   ModelLog Load (0.2ms) SELECT "model_logs".* FROM "model_logs" WHERE "model_logs"."id" = ? LIMIT 1 [["id", 10]] => #<ModelLog id: 10, logable_id: 3, logable_type: "Candidate", log: "2012-11-16 05:26:52 -0600 - Created", created_at: "2012-11-16 11:26:52", updated_at: "2012-11-16 11:26:52"> ##APPENDED MESSAGE GONE

2

I tried to implement a simple model_logger table that is polymorphic as logable. Wanted nothing more than a text field (log) that text is appended to.

The ModelLog model just has a simple set_log method def set_log(entry) self.log << "\r\n#{Time.now.to_s} - #{entry}" self.save #puts "Model Log Saved #{errors.inspect}" end

Rails only saves attributes that have changed, and in place modifications such as << or the destructive string operations (those that end with !) fool the change tracking mechanism. Either use += instead of << or call log_will_change! to tell it that you have changed that attribute.

Fred