Comparing form value with db value on edit

[roman.pike]

I am creating a small job tracker application for my office. When a job is edited, I add a new record to an audit database saying "Job edited on date ". I would also like to say what was edited. How can I do a simple compare of the form value to the database value? I would assume it would be hooked into the before_update callback. Any help would be appreciated.

[kyko]

I don't think you will need a before update callback since it really isn't a hook that you need here but rather just another variable to compare against. you can do the comparison inside the update_attrubutes if statement and save the results to your log table there.

def update_job
  @job = Job.find(params[:id]) # this gets updated
  @old_job = Job.find(params[:id]) # this stays the same so you can compare
  if @job.update_attributes(params[:job]) # @job should now be updated
    log = ""
    for key, value in @job.attributes # goes through every attribute in @job
      unless value == @old_job[key] # checks with the old version
        log << "#{key} was changed from #{@old_job[key]} to #{value}.\n" # appends log if different
      end
      # Here you can save the changes to the DB as seperate entries
    end
    # Here you can save the log to the DB as one entry
  end
end