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Last active January 31, 2024 09:16
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Awesome simple solution for Rails ActiveRecord dirty tracking associations
# Credit Brandon Weiss of http://anti-pattern.com/dirty-associations-with-activerecord
# app/models/dirty_associations.rb
module DirtyAssociations
attr_accessor :dirty
attr_accessor :_record_changes
def make_dirty(record)
self.dirty = true
self._record_changes = record
end
def changed?
dirty || super
end
end
# app/models/lolrus.rb
class Lolrus
include DirtyAssociations
has_many :buckets,
:after_add => :make_dirty,
:after_remove => :make_dirty
end
# Usage
lol = Lolrus.create!
lol.buckets << Bucket.new
lol.changed?
# => true
lol._record_changes
# => #<Bucket# ... >
lol._record_changes.changed?
# => true
lol._record_changes.changes?
# for example ...
# => {[attr] => [old_value, new_value]}
@sas1ni69
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sas1ni69 commented Mar 9, 2018

Just passing by.. 👋 😄

@yourivdlans
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yourivdlans commented Apr 17, 2019

Neat!

When adding or removing multiple records only the last one would be present in _record_changes.

You could rewrite made_dirty to get all changed records like so:

def make_dirty(record)
  self.dirty = true
  self._record_changes ||= []
  self._record_changes << record
end

Also, reload doesn't reset the _record_changes. You can overload the reload method like so:

def reload(*)
  super.tap do
    self._record_changes = nil
  end
end

@a-poliusov
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@yourivdlans hi. thanks for you solution. He does not mentioned any reload methods. Can you elaborate why we need reload?

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