osem-fcy/app/models/concerns/track_saved_changes.rb

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No EOL
1.3 KiB
Ruby

# https://github.com/ccmcbeck/after-commit
module TrackSavedChanges
extend ActiveSupport::Concern
included do
# expose the details if consumer wants to do more
attr_reader :saved_changes_history, :saved_changes_unfiltered
after_initialize :reset_saved_changes
after_save :track_saved_changes
end
# on initalize, but useful for fine grain control
def reset_saved_changes
@saved_changes_unfiltered = {}
@saved_changes_history = []
end
# filter out any changes that result in the original value
def saved_changes
@saved_changes_unfiltered.reject { |k,v| v[0] == v[1] }
end
private
# on save
def track_saved_changes
# maintain an array of ActiveModel::Dirty.changes
@saved_changes_history << changes.dup
# accumulate the most recent changes
@saved_changes_history.last.each_pair { |k, v| track_saved_change k, v }
end
# v is an an array of [prev, current]
def track_saved_change(k, v)
if @saved_changes_unfiltered.key? k
@saved_changes_unfiltered[k][1] = track_saved_value v[1]
else
@saved_changes_unfiltered[k] = v.dup
end
end
# type safe dup inspred by http://stackoverflow.com/a/20955038
def track_saved_value(v)
begin
v.dup
rescue TypeError
v
end
end
end