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@ShogunPanda
Forked from masatomo/sequence.rb
Created July 16, 2011 11:15
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adds a feature to set sequence number to Mongoid::Document
# encoding: utf-8
module Mongoid
# Include this module to add automatic sequence feature (also works for _id field, so SQL-Like autoincrement primary key can easily be simulated)
# usage:
# class KlassName
# include Mongoid::Document
# include Mongoid::Sequence
# ...
# field :number, :type=>Integer
# sequence :number
# ...
module Sequence
extend ActiveSupport::Concern
module ClassMethods
def sequence(_field)
# REPLACE FIELD DEFAULT VALUE
_field = _field.to_s
field(_field, fields[_field].options.merge(:default => lambda{ self.class.set_from_sequence(_field)}))
end
def set_from_sequence(_field)
sequences = self.db.collection("__sequences")
counter_id = "#{self.class.name.underscore}_#{_field}"
# Increase the sequence value and also avoids conflicts
catch(:value) do
value = nil
begin
value = sequences.find_and_modify(
:query => {"_id" => counter_id},
:update=> {"$inc" => {"value" => 1}},
:new => true,
:upsert => true
).send("[]", "value")
end while self.first({:conditions => {_field => value}})
throw :value, value
end
end
def reset_sequence(_field)
sequences = self.db.collection("__sequences")
counter_id = "#{self.class.name.underscore}_#{_field}"
sequences.find_and_modify(:query => {"_id" => counter_id}, :update=> {"$set" => {"value" => 0}}, :new => true, :upsert => true)
end
end
end
end
@goncalossilva
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@paulsfds I'm using ruby 1.9.3p125 and bundler 1.1.1 here.

@goncalossilva
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@paulsfds I'm 99% confident that you won't have that issue anymore with mongoid-sequence 0.1 (released a few minutes ago). Try it! :)

@paulsfds
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@goncalossilva I'm playing around with this gem again (I had forgotten about it for a month), and it seems to be working but I noticed one issue. The model's find() method only takes an integer, and it errors out if you try and pass it a string.

1.9.2-p290 :022 > Sample.find(1)
=> #<Sample _id: 1, _type: nil, name: nil>

1.9.2-p290 :024 > Sample.find("1")
BSON::InvalidObjectId: illegal ObjectId format: 1

The default Mongoid implementation of find takes only a string. A workaround is to just force the param to be an integer like so:
@sample = Sample.find(params[:id].to_i)

I noticed that in your gem, the id actually becomes an integer whereas in Mongoid, the id is a BSON::ObjectId object. This may be the problem, is there a way to store the sequential numbers (for ids) as BSON::ObjectId instead of as in integer?

1.9.2-p290 :027 > Sample.find(1)._id
=> 1
1.9.2-p290 :028 > Sample.find(1)._id.is_a?(Integer)
=> true

1.9.2-p290 :009 > Event.first._id
=> BSON::ObjectId('4f98e4271d41c827cb000007')
1.9.2-p290 :010 > Event.first._id.is_a?(Integer)
=> false

@goncalossilva
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@paulsfds I believe that's the default behavior when you field :my_id, :type => Integer... the sequencing code doesn't play with any of that. Please open an issue with this if you think it's something else :)

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