Module: Familia::Features

Included in:
DataType
Defined in:
lib/familia/features.rb,
lib/familia/features/safe_dump.rb,
lib/familia/features/expiration.rb,
lib/familia/features/quantization.rb,
lib/familia/features/encrypted_fields.rb,
lib/familia/features/transient_fields.rb

Overview

lib/familia/features/quantization.rb

Defined Under Namespace

Modules: EncryptedFields, Expiration, Quantization, SafeDump, TransientFields

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#features_enabled ⇒ Object (readonly)

Returns the value of attribute features_enabled.



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# File 'lib/familia/features.rb', line 12

def features_enabled
  @features_enabled
end

Instance Method Details

#feature(feature_name = nil) ⇒ Object 



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# File 'lib/familia/features.rb', line 14

def feature(feature_name = nil)
  @features_enabled ||= []

  return features_enabled if feature_name.nil?

  # If there's a value provied check that it's a valid feature
  feature_name = feature_name.to_sym
  unless Familia::Base.features_available.key?(feature_name)
    raise Familia::Problem, "Unsupported feature: #{feature_name}"
  end

  # If the feature is already available, do nothing but log about it
  if features_enabled.member?(feature_name)
    Familia.warn "[#{self.class}] feature already available: #{feature_name}"
    return
  end

  if Familia.debug?
    Familia.trace :FEATURE, nil, "#{self} includes #{feature_name.inspect}", caller(1..1)
  end

  # Add it to the list available features_enabled for Familia::Base classes.
  features_enabled << feature_name

  klass = Familia::Base.features_available[feature_name]

  # Validate dependencies
  feature_def = Familia::Base.feature_definitions[feature_name]
  if feature_def&.depends_on&.any?
    missing = feature_def.depends_on - features_enabled
    raise Familia::Problem, "#{feature_name} requires: #{missing.join(', ')}" if missing.any?
  end

  # Extend the Familia::Base subclass (e.g. Customer) with the feature module
  include klass

  # NOTE: Do we want to extend Familia::DataType here? That would make it
  # possible to call safe_dump on relations fields (e.g. list, zset, hashkey).
  #
  # The challenge is that DataType classes (List, Set, etc.) are shared across
  # all Horreum models. If Customer extends DataType with safe_dump, then
  # Session's lists would also have it. Not ideal. If that's all we wanted
  # then we can do that by looping through every DataType class here.
  #
  # We'd need to extend the DataType instances for each Horreum subclass. That
  # avoids it getting included multiple times per DataType
end