The 'safe' write concern option has been deprecated in favor of 'w'

[xjia1]

I'm running the code below and got a warning message:

[DEPRECATED] The 'safe' write concern option has been deprecated in favor of 'w'.

Google gives something related: http://www.manning-sandbox.com/thread.jspa?messageID=135496&tstart=0

require 'mongo_mapper'

ENV['MONGODB_URI'] = 'mongodb://localhost/test'
MongoMapper.setup({'production' => {'uri' => ENV['MONGODB_URI']}}, 'production')

class User
  include MongoMapper::Document

  key :name, String
  key :age, Integer

  many :hobbies
end

class Hobby
  include MongoMapper::EmbeddedDocument

  key :name, String
  key :started, Time
end

user = User.new(:name => 'Brandon')
user.hobbies.build(:name => 'Programming', :started => 10.years.ago)
user.save!
User.where(:name => 'Brandon').first

[brndnblck]

The deprecation notice is actually coming from the mongo-ruby-driver one level below:
https://github.com/mongodb/mongo-ruby-driver/blob/1.8.4/lib/mongo/util/write_concern.rb#L10

In short:

# deprecated syntax, triggers warning
collection.save doc, :safe => true
# new syntax for "safe" mode
collection.save doc, :w => 1

You can read more about the deprecation of "safe" here:
http://blog.mongodb.org/post/36666163412/introducing-mongoclient

You can read more about MongoDB's write concerns here:
http://docs.mongodb.org/manual/core/write-operations/#write-concern

[szymon-jez]

@stfairy Here is a quick and dirty monkey patch:

# Monkey Patch to solve issue https://github.com/jnunemaker/mongomapper/issues/507
module MongoMapper
  module Plugins
    module Querying
      private
        def save_to_collection(options={})
          @_new = false
          collection.save(to_mongo, :w => options[:safe] ? 1 : 0)
        end
    end
  end
end

I wonder, why is this not already fixed?

[shevaun]

+1

[theirishpenguin]

FYI, the master has this fixed (though not the latest gem).

[jnunemaker]

This is fixed in master. Closing.