Class: TrackChanges::Snapshot

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
app/models/track_changes/snapshot.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.dump_attribute_value(value) ⇒ Object 



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# File 'app/models/track_changes/snapshot.rb', line 16

def self.dump_attribute_value(value)
  case value
  when ActiveRecord::Relation
    dump_attribute_value(value.to_a).sort
  when Array
    value.map {|member| dump_attribute_value(member) }
  when ActiveRecord::Base
    value.send(value.class.primary_key)
  else
    value
  end
end

.record_state(record) ⇒ Object

Returns a hash of the current values for all tracked fields on the record



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# File 'app/models/track_changes/snapshot.rb', line 12

def self.record_state(record)
  Hash[record.class.track_changes_fields.collect {|method_name| [method_name, dump_attribute_value(record.send(method_name))]   }]
end

Instance Method Details

#capture_record_state ⇒ Object 



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# File 'app/models/track_changes/snapshot.rb', line 51

def capture_record_state
  self.state = self.class.record_state(record)
end

#create_diff(diff_attributes = {}) ⇒ Object

Creates a diff object that shows the changes between this snapshot and the record’s state



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# File 'app/models/track_changes/snapshot.rb', line 30

def create_diff(diff_attributes = {})
  record_state   = self.class.record_state(record)
  snapshot_state = self.state
  from           = {}
  to             = {}

  record.class.track_changes_fields.each do |key|
    if snapshot_state.key?(key) && snapshot_state[key] != record_state[key] # We check for the existence of the key in the snapshot before recording so we don't declare newly tracked attributes as "changed" on their first time recorded
      from[key] = snapshot_state[key]
      to[key] = record_state[key]
    end
  end
  diff_attributes = diff_attributes.reverse_merge(:from => from, :to => to)
  record.diffs.create!(diff_attributes) unless diff_attributes[:from].empty? && diff_attributes[:to].empty?
end

#update ⇒ Object

Updates the snapshot to the current record state



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# File 'app/models/track_changes/snapshot.rb', line 47

def update
  save
end