Class: RESTFramework::NativeSerializer

Inherits:
BaseSerializer show all
Defined in:
lib/rest_framework/serializers.rb

Overview

This serializer uses ‘.serializable_hash` to convert objects to Ruby primitives (with the top-level being either an array or a hash).

Instance Attribute Summary

Attributes inherited from BaseSerializer

#object

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from BaseSerializer

#associations, cache_enabled?, fragment_cache_enabled?, #serializable_hash

Constructor Details

#initialize(object = nil, *args, many: nil, model: nil, **kwargs) ⇒ NativeSerializer

Accept/ignore ‘*args` to be compatible with the `ActiveModel::Serializer#initialize` signature.



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# File 'lib/rest_framework/serializers.rb', line 48

def initialize(object=nil, *args, many: nil, model: nil, **kwargs)
  super(object, *args, **kwargs)

  if many.nil?
    # Determine if we are dealing with many objects or just one.
    @many = @object.is_a?(Enumerable)
  else
    @many = many
  end

  # Determine model either explicitly, or by inspecting @object or @controller.
  @model = model
  @model ||= @object.class if @object.is_a?(ActiveRecord::Base)
  @model ||= @object[0].class if
    @many && @object.is_a?(Enumerable) && @object.is_a?(ActiveRecord::Base)

  @model ||= @controller.class.get_model if @controller
end

Class Method Details

.[](key) ⇒ Object

Allow a serializer class to be used as a hash directly in a nested serializer config.



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# File 'lib/rest_framework/serializers.rb', line 284

def self.[](key)
  @_nested_config ||= self.new.get_serializer_config
  return @_nested_config[key]
end

.[]=(key, value) ⇒ Object 



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# File 'lib/rest_framework/serializers.rb', line 289

def self.[]=(key, value)
  @_nested_config ||= self.new.get_serializer_config
  return @_nested_config[key] = value
end

.filter_subcfg(subcfg, fields:, add: false, only: false) ⇒ Object

Helper to filter a single subconfig for specific keys. By default, keys from ‘fields` are removed from the provided `subcfg`. There are two (mutually exclusive) options to adjust the behavior:

`add`: Add any `fields` to the `subcfg` which aren't already in the `subcfg`.
`only`: Remove any values found in the `subcfg` not in `fields`.



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# File 'lib/rest_framework/serializers.rb', line 110

def self.filter_subcfg(subcfg, fields:, add: false, only: false)
  raise "`add` and `only` conflict with one another" if add && only

  # Don't process nil `subcfg`s.
  return subcfg unless subcfg

  if subcfg.is_a?(Array)
    subcfg = subcfg.transform_values(&:to_sym)

    if add
      # Only add fields which are not already included.
      subcfg += fields - subcfg
    elsif only
      subcfg.select! { |c| c.in?(fields) }
    else
      subcfg -= fields
    end
  elsif subcfg.is_a?(Hash)
    subcfg = subcfg.symbolize_keys

    if add
      # Add doesn't make sense in a hash context since we wouldn't know the values.
    elsif only
      subcfg.select! { |k, _v| k.in?(fields) }
    else
      subcfg.reject! { |k, _v| k.in?(fields) }
    end
  else  # Subcfg is a single element (assume string/symbol).
    subcfg = subcfg.to_sym

    if add
      subcfg = subcfg.in?(fields) ? fields : [subcfg, *fields]
    elsif only
      subcfg = subcfg.in?(fields) ? subcfg : []
    else
      subcfg = subcfg.in?(fields) ? [] : subcfg
    end
  end

  return subcfg
end

Instance Method Details

#[](key) ⇒ Object

Allow a serializer instance to be used as a hash directly in a nested serializer config.



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# File 'lib/rest_framework/serializers.rb', line 273

def [](key)
  @_nested_config ||= self.get_serializer_config
  return @_nested_config[key]
end

#[]=(key, value) ⇒ Object 



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# File 'lib/rest_framework/serializers.rb', line 278

def []=(key, value)
  @_nested_config ||= self.get_serializer_config
  return @_nested_config[key] = value
end

#_get_raw_serializer_config ⇒ Object

Get the raw serializer config. Use ‘deep_dup` on any class mutables (array, hash, etc) to avoid mutating class state.



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# File 'lib/rest_framework/serializers.rb', line 204

def _get_raw_serializer_config
  # Return a locally defined serializer config if one is defined.
  if local_config = self.get_local_native_serializer_config
    return local_config.deep_dup
  end

  # Return a serializer config if one is defined on the controller.
  if serializer_config = self.get_controller_native_serializer_config
    return serializer_config.deep_dup
  end

  # If the config wasn't determined, build a serializer config from controller fields.
  if fields = @controller&.get_fields
    fields = fields.deep_dup

    columns = []
    includes = []
    methods = []
    if @model
      fields.each do |f|
        if f.in?(@model.column_names)
          columns << f
        elsif @model.reflections.key?(f)
          includes << f
        elsif @model.method_defined?(f)
          methods << f
        end
      end
    else
      columns = fields
    end

    return {only: columns, include: includes, methods: methods}
  end

  # By default, pass an empty configuration, allowing the serialization of all columns.
  return {}
end

#_serialize(record, config, serializer_methods) ⇒ Object

Internal helper to serialize a single record and merge results of ‘serializer_methods`.



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# File 'lib/rest_framework/serializers.rb', line 249

def _serialize(record, config, serializer_methods)
  # Ensure serializer_methods is either falsy, or an array.
  if serializer_methods && !serializer_methods.respond_to?(:to_ary)
    serializer_methods = [serializer_methods]
  end

  # Merge serialized record with any serializer method results.
  return record.serializable_hash(config).merge(
    serializer_methods&.map { |m| [m.to_sym, self.send(m, record)] }.to_h,
  )
end

#filter_except(cfg) ⇒ Object

Helper to filter out configuration properties based on the :except query parameter.



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# File 'lib/rest_framework/serializers.rb', line 153

def filter_except(cfg)
  return cfg unless @controller

  except_param = @controller.class.try(:native_serializer_except_query_param)
  only_param = @controller.class.try(:native_serializer_only_query_param)
  if except_param && except = @controller.request.query_parameters[except_param].presence
    except = except.split(",").map(&:strip).map(&:to_sym)

    unless except.empty?
      # Filter `only`, `except` (additive), `include`, `methods`, and `serializer_methods`.
      if cfg[:only]
        cfg[:only] = self.class.filter_subcfg(cfg[:only], fields: except)
      elsif cfg[:except]
        cfg[:except] = self.class.filter_subcfg(cfg[:except], fields: except, add: true)
      else
        cfg[:except] = except
      end
      cfg[:include] = self.class.filter_subcfg(cfg[:include], fields: except)
      cfg[:methods] = self.class.filter_subcfg(cfg[:methods], fields: except)
      cfg[:serializer_methods] = self.class.filter_subcfg(
        cfg[:serializer_methods], fields: except
      )
    end
  elsif only_param && only = @controller.request.query_parameters[only_param].presence
    only = only.split(",").map(&:strip).map(&:to_sym)

    unless only.empty?
      # Filter `only`, `except` (additive), `include`, and `methods`.
      if cfg[:only]
        cfg[:only] = self.class.filter_subcfg(cfg[:only], fields: only, only: true)
      elsif cfg[:except]
        # For the `except` part of the serializer, we need to append any columns not in `only`.
        model = @controller.class.get_model
        except_cols = model&.column_names&.map(&:to_sym)&.reject { |c| c.in?(only) }
        cfg[:except] = self.class.filter_subcfg(cfg[:except], fields: except_cols, add: true)
      else
        cfg[:only] = only
      end
      cfg[:include] = self.class.filter_subcfg(cfg[:include], fields: only, only: true)
      cfg[:methods] = self.class.filter_subcfg(cfg[:methods], fields: only, only: true)
      cfg[:serializer_methods] = self.class.filter_subcfg(
        cfg[:serializer_methods], fields: only, only: true
      )
    end
  end

  return cfg
end

#get_action ⇒ Object

Get controller action, if possible.



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# File 'lib/rest_framework/serializers.rb', line 68

def get_action
  return @controller&.action_name&.to_sym
end

#get_controller_native_serializer_config ⇒ Object

Helper to get a native serializer configuration from the controller.



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# File 'lib/rest_framework/serializers.rb', line 92

def get_controller_native_serializer_config
  return nil unless @controller

  if @many == true
    controller_serializer = @controller.class.try(:native_serializer_plural_config)
  elsif @many == false
    controller_serializer = @controller.class.try(:native_serializer_singular_config)
  end

  return controller_serializer || @controller.class.try(:native_serializer_config)
end

#get_local_native_serializer_config ⇒ Object

Get a locally defined native serializer configuration, if one is defined.



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# File 'lib/rest_framework/serializers.rb', line 73

def get_local_native_serializer_config
  action = self.get_action

  if action && self.action_config
    # Index action should use :list serializer config if :index is not provided.
    action = :list if action == :index && !self.action_config.key?(:index)

    return self.action_config[action] if self.action_config[action]
  end

  # No action_config, so try singular/plural config if explicitly instructed to via @many.
  return self.plural_config if @many == true && self.plural_config
  return self.singular_config if @many == false && self.singular_config

  # Lastly, try returning the default config, or singular/plural config in that order.
  return self.config || self.singular_config || self.plural_config
end

#get_serializer_config ⇒ Object

Get a configuration passable to ‘serializable_hash` for the object, filtered if required.



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# File 'lib/rest_framework/serializers.rb', line 244

def get_serializer_config
  return filter_except(self._get_raw_serializer_config)
end

#serialize(*args) ⇒ Object 



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# File 'lib/rest_framework/serializers.rb', line 261

def serialize(*args)
  config = self.get_serializer_config
  serializer_methods = config.delete(:serializer_methods)

  if @object.respond_to?(:to_ary)
    return @object.map { |r| self._serialize(r, config, serializer_methods) }
  end

  return self._serialize(@object, config, serializer_methods)
end