Module: IronTrail::ChangeModelConcern

Extended by:
ActiveSupport::Concern
Defined in:
lib/iron_trail/change_model_concern.rb

Defined Under Namespace

Modules: ClassMethods

Instance Method Summary collapse

Instance Method Details

#compute_changeset ⇒ Object

This mimics the method with the same name available in the papertrail gem. It is an extended rec_delta, where attributes values are properly deserialized as rails’ ActiveRecord would do.

For instance, timestamps are serialized as strings in JSON, so rec_delta would return strings for timestamps. Using this method, it’d return a proper timestamp deserialized from the string.

This method doesn’t do caching and always computes the full thing. It’s up to the user to perform caching if wanted.



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# File 'lib/iron_trail/change_model_concern.rb', line 36

def compute_changeset
  return nil unless update_operation?

  klass = rec_class

  HashWithIndifferentAccess.new.tap do |changes|
    rec_delta.each do |col_name, in_delta|
      type_class = klass.type_for_attribute(col_name)
      out_delta = in_delta.map { |val| type_class.deserialize(val) }

      changes[col_name] = out_delta
    end
  end
end

#delete_operation? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/iron_trail/change_model_concern.rb', line 9

def delete_operation? = (operation == 'd')

#insert_operation? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/iron_trail/change_model_concern.rb', line 7

def insert_operation? = (operation == 'i')

#rec_class ⇒ Object

We don’t store the class name of the object, but we do store the rec_table. This method infers the class name from the rec_table and also the “type” attribute in the stored object in case it’s a rails STI class.

It returns the class instance. Raises an error in case the class couldn’t be inferred.



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# File 'lib/iron_trail/change_model_concern.rb', line 21

def rec_class
  source_attributes = (delete_operation? ? rec_old : rec_new)
  Reifier.model_from_table_name(rec_table, source_attributes.fetch('type', nil))
end

#reify ⇒ Object 



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# File 'lib/iron_trail/change_model_concern.rb', line 11

def reify
  Reifier.reify(self)
end

#update_operation? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/iron_trail/change_model_concern.rb', line 8

def update_operation? = (operation == 'u')