lib/alba/resource.rb in alba-1.6.0 vs lib/alba/resource.rb in alba-2.0.0

@@ -1,15 +1,18 @@
 require_relative 'association'
+require_relative 'conditional_attribute'
 require_relative 'typed_attribute'
+require_relative 'nested_attribute'
 require_relative 'deprecation'
+require_relative 'layout'
 
 module Alba
   # This module represents what should be serialized
   module Resource
     # @!parse include InstanceMethods
     # @!parse extend ClassMethods
-    DSLS = {_attributes: {}, _key: nil, _key_for_collection: nil, _meta: nil, _transform_type: :none, _transforming_root_key: false, _on_error: nil, _on_nil: nil, _layout: nil}.freeze # rubocop:disable Layout/LineLength
+    DSLS = {_attributes: {}, _key: nil, _key_for_collection: nil, _meta: nil, _transform_type: :none, _transforming_root_key: false, _on_error: nil, _on_nil: nil, _layout: nil, _collection_key: nil}.freeze # rubocop:disable Layout/LineLength
     private_constant :DSLS
 
     WITHIN_DEFAULT = Object.new.freeze
     private_constant :WITHIN_DEFAULT
 
@@ -33,226 +36,239 @@
       # @param object [Object] the object to be serialized
       # @param params [Hash] user-given Hash for arbitrary data
       # @param within [Object, nil, false, true] determines what associations to be serialized. If not set, it serializes all associations.
       def initialize(object, params: {}, within: WITHIN_DEFAULT)
         @object = object
-        @params = params.freeze
+        @params = params
         @within = within
         @method_existence = {} # Cache for `respond_to?` result
-        DSLS.each_key { |name| instance_variable_set("@#{name}", self.class.public_send(name)) }
+        DSLS.each_key { |name| instance_variable_set("@#{name}", self.class.__send__(name)) }
       end
 
       # Serialize object into JSON string
       #
-      # @param key [Symbol, nil, true] DEPRECATED, use root_key instead
       # @param root_key [Symbol, nil, true]
       # @param meta [Hash] metadata for this seialization
       # @return [String] serialized JSON string
-      def serialize(key: nil, root_key: nil, meta: {})
-        Alba::Deprecation.warn '`key` option to `serialize` method is deprecated, use `root_key` instead.' if key
-        key = key.nil? && root_key.nil? ? fetch_key : root_key || key
-        hash = if key && key != ''
-                 h = {key.to_s => serializable_hash}
-                 hash_with_metadata(h, meta)
-               else
-                 serializable_hash
-               end
-        serialize_with(hash)
+      def serialize(root_key: nil, meta: {})
+        serialize_with(as_json(root_key: root_key, meta: meta))
       end
-      alias to_json serialize
 
+      if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('3.0')
+        # For Rails compatibility
+        # The first options is a dummy parameter but required
+        # You can pass empty Hash if you don't want to pass any arguments
+        #
+        # @see #serialize
+        # @see https://github.com/rails/rails/blob/7-0-stable/actionpack/lib/action_controller/metal/renderers.rb#L156
+        def to_json(options, root_key: nil, meta: {})
+          _to_json(root_key, meta, options)
+        end
+      else
+        # For Rails compatibility
+        # The first options is a dummy parameter
+        #
+        # @see #serialize
+        # @see https://github.com/rails/rails/blob/7-0-stable/actionpack/lib/action_controller/metal/renderers.rb#L156
+        def to_json(options = {}, root_key: nil, meta: {})
+          _to_json(root_key, meta, options)
+        end
+      end
+
+      # Returns a Hash correspondng {Resource#serialize}
+      #
+      # @param root_key [Symbol, nil, true]
+      # @param meta [Hash] metadata for this seialization
+      # @param symbolize_root_key [Boolean] determines if root key should be symbolized
+      # @return [Hash]
+      def as_json(root_key: nil, meta: {})
+        key = root_key.nil? ? fetch_key : root_key.to_s
+        if key && !key.empty?
+          h = {key => serializable_hash}
+          hash_with_metadata(h, meta)
+        else
+          serializable_hash
+        end
+      end
+
       # A Hash for serialization
       #
       # @return [Hash]
       def serializable_hash
-        collection? ? @object.map(&converter) : converter.call(@object)
+        collection? ? serializable_hash_for_collection : converter.call(@object)
       end
       alias to_h serializable_hash
 
-      # @deprecated Use {#serializable_hash} instead
-      def to_hash
-        warn '[DEPRECATION] `to_hash` is deprecated, use `serializable_hash` instead.'
-        serializable_hash
-      end
-
       private
 
-      attr_reader :serialized_json # Mainly for layout
-
       def encode(hash)
         Alba.encoder.call(hash)
       end
 
+      def _to_json(root_key, meta, options)
+        options.reject! { |k, _| %i[layout prefixes template status].include?(k) } # Rails specific guard
+        # TODO: use `filter_map` after dropping support of Ruby 2.6
+        names = options.map { |k, v| k unless v.nil? }
+        names.compact!
+        unless names.empty?
+          names.sort!
+          names.map! { |s| "\"#{s}\"" }
+          message = "You passed #{names.join(', ')} options but ignored. Please refer to the document: https://github.com/okuramasafumi/alba/blob/main/docs/rails.md"
+          Kernel.warn(message)
+        end
+        serialize(root_key: root_key, meta: meta)
+      end
+
       def serialize_with(hash)
         serialized_json = encode(hash)
         return serialized_json unless @_layout
 
-        @serialized_json = serialized_json
-        if @_layout.is_a?(String) # file
-          ERB.new(File.read(@_layout)).result(binding)
-
-        else # inline
-          serialize_within_inline_layout
-        end
+        @_layout.serialize(resource: self, serialized_json: serialized_json, binding: binding)
       end
 
-      def serialize_within_inline_layout
-        inline = instance_eval(&@_layout)
-        case inline
-        when Hash then encode(inline)
-        when String then inline
-        else
-          raise Alba::Error, 'Inline layout must be a Proc returning a Hash or a String'
-        end
-      end
-
       def hash_with_metadata(hash, meta)
         return hash if meta.empty? && @_meta.nil?
 
         metadata = @_meta ? instance_eval(&@_meta).merge(meta) : meta
         hash[:meta] = metadata
         hash
       end
 
+      def serializable_hash_for_collection
+        if @_collection_key
+          @object.to_h { |item| [item.public_send(@_collection_key).to_s, converter.call(item)] }
+        else
+          @object.each_with_object([], &collection_converter)
+        end
+      end
+
+      # @return [String]
       def fetch_key
-        collection? ? _key_for_collection : _key
+        k = collection? ? _key_for_collection : _key
+        transforming_root_key? ? transform_key(k) : k
       end
 
       def _key_for_collection
-        return @_key_for_collection.to_s unless @_key_for_collection == true && Alba.inferring
-
-        key = resource_name.pluralize
-        transforming_root_key? ? transform_key(key) : key
+        if Alba.inferring
+          @_key_for_collection == true ? resource_name(pluralized: true) : @_key_for_collection.to_s
+        else
+          @_key_for_collection == true ? raise_root_key_inference_error : @_key_for_collection.to_s
+        end
       end
 
       # @return [String]
       def _key
-        return @_key.to_s unless @_key == true && Alba.inferring
+        if Alba.inferring
+          @_key == true ? resource_name(pluralized: false) : @_key.to_s
+        else
+          @_key == true ? raise_root_key_inference_error : @_key.to_s
+        end
+      end
 
-        transforming_root_key? ? transform_key(resource_name) : resource_name
+      def resource_name(pluralized: false)
+        class_name = self.class.name
+        inflector = Alba.inflector
+        name = inflector.demodulize(class_name).delete_suffix('Resource')
+        underscore_name = inflector.underscore(name)
+        pluralized ? inflector.pluralize(underscore_name) : underscore_name
       end
 
-      def resource_name
-        @resource_name ||= self.class.name.demodulize.delete_suffix('Resource').underscore
+      def raise_root_key_inference_error
+        raise Alba::Error, 'You must call Alba.enable_inference! to set root_key to true for inferring root key.'
       end
 
       def transforming_root_key?
-        @_transforming_root_key.nil? ? Alba.transforming_root_key : @_transforming_root_key
+        @_transforming_root_key
       end
 
-      # rubocop:disable Metrics/MethodLength
       def converter
         lambda do |object|
-          arrays = attributes.map do |key, attribute|
-            key_and_attribute_body_from(object, key, attribute)
-          rescue ::Alba::Error, FrozenError, TypeError
-            raise
-          rescue StandardError => e
-            handle_error(e, object, key, attribute)
-          end
-          arrays.compact!
-          arrays.to_h
+          attributes_to_hash(object, {})
         end
       end
-      # rubocop:enable Metrics/MethodLength
 
-      # This is default behavior for getting attributes for serialization
-      # Override this method to filter certain attributes
-      def attributes
-        @_attributes
-      end
-
-      def key_and_attribute_body_from(object, key, attribute)
-        key = transform_key(key)
-        if attribute.is_a?(Array) # Conditional
-          conditional_attribute(object, key, attribute)
-        else
-          fetched_attribute = fetch_attribute(object, key, attribute)
-          [key, fetched_attribute]
+      def collection_converter
+        lambda do |object, a|
+          a << {}
+          h = a.last
+          attributes_to_hash(object, h)
+          a
         end
       end
 
-      def conditional_attribute(object, key, attribute)
-        condition = attribute.last
-        if condition.is_a?(Proc)
-          conditional_attribute_with_proc(object, key, attribute.first, condition)
-        else
-          conditional_attribute_with_symbol(object, key, attribute.first, condition)
+      def attributes_to_hash(object, hash)
+        attributes.each do |key, attribute|
+          set_key_and_attribute_body_from(object, key, attribute, hash)
+        rescue ::Alba::Error, FrozenError, TypeError
+          raise
+        rescue StandardError => e
+          handle_error(e, object, key, attribute, hash)
         end
+        hash
       end
 
-      def conditional_attribute_with_proc(object, key, attribute, condition)
-        arity = condition.arity
-        # We can return early to skip fetch_attribute
-        return if arity <= 1 && !instance_exec(object, &condition)
-
-        fetched_attribute = fetch_attribute(object, key, attribute)
-        attr = attribute.is_a?(Alba::Association) ? attribute.object : fetched_attribute
-        return if arity >= 2 && !instance_exec(object, attr, &condition)
-
-        [key, fetched_attribute]
+      # This is default behavior for getting attributes for serialization
+      # Override this method to filter certain attributes
+      def attributes
+        @_attributes
       end
 
-      def conditional_attribute_with_symbol(object, key, attribute, condition)
-        return unless __send__(condition)
-
-        [key, fetch_attribute(object, key, attribute)]
+      def set_key_and_attribute_body_from(object, key, attribute, hash)
+        key = transform_key(key)
+        value = fetch_attribute(object, key, attribute)
+        hash[key] = value unless value == ConditionalAttribute::CONDITION_UNMET
       end
 
-      def handle_error(error, object, key, attribute)
-        on_error = @_on_error || Alba._on_error
-        case on_error
-        when :raise, nil then raise
-        when :nullify then [key, nil]
+      def handle_error(error, object, key, attribute, hash)
+        on_error = @_on_error || :raise
+        case on_error # rubocop:disable Style/MissingElse
+        when :raise, nil then raise(error)
+        when :nullify then hash[key] = nil
         when :ignore then nil
-        when Proc then on_error.call(error, object, key, attribute, self.class)
-        else
-          raise ::Alba::Error, "Unknown on_error: #{on_error.inspect}"
+        when Proc
+          key, value = on_error.call(error, object, key, attribute, self.class)
+          hash[key] = value
         end
       end
 
-      # rubocop:disable Metrics/MethodLength
       # @return [Symbol]
-      def transform_key(key)
-        return key if @_transform_type == :none
-
+      def transform_key(key) # rubocop:disable Metrics/CyclomaticComplexity
         key = key.to_s
-        # TODO: Using default inflector here is for backward compatibility
-        # From 2.0 it'll raise error when inflector is nil
-        inflector = Alba.inflector || begin
-          require_relative 'default_inflector'
-          Alba::DefaultInflector
-        end
+        return key if @_transform_type == :none || key.empty? # We can skip transformation
+
+        inflector = Alba.inflector
+        raise Alba::Error, 'Inflector is nil. You can set inflector with `Alba.enable_inference!(with: :active_support)` for example.' unless inflector
+
         case @_transform_type # rubocop:disable Style/MissingElse
         when :camel then inflector.camelize(key)
         when :lower_camel then inflector.camelize_lower(key)
         when :dash then inflector.dasherize(key)
         when :snake then inflector.underscore(key)
-        end.to_sym
+        end
       end
-      # rubocop:enable Metrics/MethodLength
 
-      def fetch_attribute(object, key, attribute)
+      def fetch_attribute(object, key, attribute) # rubocop:disable Metrics/CyclomaticComplexity
         value = case attribute
                 when Symbol then fetch_attribute_from_object_and_resource(object, attribute)
                 when Proc then instance_exec(object, &attribute)
                 when Alba::Association then yield_if_within(attribute.name.to_sym) { |within| attribute.to_h(object, params: params, within: within) }
-                when TypedAttribute then attribute.value(object)
+                when TypedAttribute, NestedAttribute then attribute.value(object)
+                when ConditionalAttribute then attribute.with_passing_condition(resource: self, object: object) { |attr| fetch_attribute(object, key, attr) }
                 else
                   raise ::Alba::Error, "Unsupported type of attribute: #{attribute.class}"
                 end
         value.nil? && nil_handler ? instance_exec(object, key, attribute, &nil_handler) : value
       end
 
       def fetch_attribute_from_object_and_resource(object, attribute)
         has_method = @method_existence[attribute]
         has_method = @method_existence[attribute] = object.respond_to?(attribute) if has_method.nil?
-        has_method ? object.public_send(attribute) : __send__(attribute, object)
+        has_method ? object.__send__(attribute) : __send__(attribute, object)
       end
 
       def nil_handler
-        @nil_handler ||= (@_on_nil || Alba._on_nil)
+        @_on_nil
       end
 
       def yield_if_within(association_name)
         within = check_within(association_name)
         yield(within) if within
@@ -302,22 +318,22 @@
         assign_attributes_with_types(attrs_with_types, if_value)
       end
 
       def assign_attributes(attrs, if_value)
         attrs.each do |attr_name|
-          attr = if_value ? [attr_name.to_sym, if_value] : attr_name.to_sym
+          attr = if_value ? ConditionalAttribute.new(body: attr_name.to_sym, condition: if_value) : attr_name.to_sym
           @_attributes[attr_name.to_sym] = attr
         end
       end
       private :assign_attributes
 
       def assign_attributes_with_types(attrs_with_types, if_value)
         attrs_with_types.each do |attr_name, type_and_converter|
           attr_name = attr_name.to_sym
           type, type_converter = type_and_converter
           typed_attr = TypedAttribute.new(name: attr_name, type: type, converter: type_converter)
-          attr = if_value ? [typed_attr, if_value] : typed_attr
+          attr = if_value ? ConditionalAttribute.new(body: typed_attr, condition: if_value) : typed_attr
           @_attributes[attr_name] = attr
         end
       end
       private :assign_attributes_with_types
 
@@ -330,42 +346,63 @@
       # @raise [ArgumentError] if block is absent
       # @return [void]
       def attribute(name, **options, &block)
         raise ArgumentError, 'No block given in attribute method' unless block
 
-        @_attributes[name.to_sym] = options[:if] ? [block, options[:if]] : block
+        @_attributes[name.to_sym] = options[:if] ? ConditionalAttribute.new(body: block, condition: options[:if]) : block
       end
 
       # Set association
       #
       # @param name [String, Symbol] name of the association, used as key when `key` param doesn't exist
       # @param condition [Proc, nil] a Proc to modify the association
-      # @param resource [Class<Alba::Resource>, String, nil] representing resource for this association
+      # @param resource [Class<Alba::Resource>, String, Proc, nil] representing resource for this association
       # @param key [String, Symbol, nil] used as key when given
+      # @param params [Hash] params override for the association
       # @param options [Hash<Symbol, Proc>]
       # @option options [Proc] if a condition to decide if this association should be serialized
       # @param block [Block]
       # @return [void]
       # @see Alba::Association#initialize
-      def association(name, condition = nil, resource: nil, key: nil, **options, &block)
-        nesting = self.name&.rpartition('::')&.first
-        assoc = Association.new(name: name, condition: condition, resource: resource, nesting: nesting, &block)
-        @_attributes[key&.to_sym || name.to_sym] = options[:if] ? [assoc, options[:if]] : assoc
+      def association(name, condition = nil, resource: nil, key: nil, params: {}, **options, &block)
+        key_transformation = @_key_transformation_cascade ? @_transform_type : :none
+        assoc = Association.new(
+          name: name, condition: condition, resource: resource, params: params, nesting: nesting, key_transformation: key_transformation,
+&block
+        )
+        @_attributes[key&.to_sym || name.to_sym] = options[:if] ? ConditionalAttribute.new(body: assoc, condition: options[:if]) : assoc
       end
       alias one association
       alias many association
       alias has_one association
       alias has_many association
 
-      # Set key
+      def nesting
+        if name.nil?
+          nil
+        else
+          name.rpartition('::').first.tap { |n| n.empty? ? nil : n }
+        end
+      end
+      private :nesting
+
+      # Set a nested attribute with the given block
       #
-      # @param key [String, Symbol]
-      # @deprecated Use {#root_key} instead
-      def key(key)
-        Alba::Deprecation.warn '[DEPRECATION] `key` is deprecated, use `root_key` instead.'
-        @_key = key.respond_to?(:to_sym) ? key.to_sym : key
+      # @param name [String, Symbol] key name
+      # @param options [Hash<Symbol, Proc>]
+      # @option options [Proc] if a condition to decide if this attribute should be serialized
+      # @param block [Block] the block called during serialization
+      # @raise [ArgumentError] if block is absent
+      # @return [void]
+      def nested_attribute(name, **options, &block)
+        raise ArgumentError, 'No block given in attribute method' unless block
+
+        key_transformation = @_key_transformation_cascade ? @_transform_type : :none
+        attribute = NestedAttribute.new(key_transformation: key_transformation, &block)
+        @_attributes[name.to_sym] = options[:if] ? ConditionalAttribute.new(body: attribute, condition: options[:if]) : attribute
       end
+      alias nested nested_attribute
 
       # Set root key
       #
       # @param key [String, Symbol]
       # @param key_for_collection [String, Symbol]
@@ -373,17 +410,17 @@
       def root_key(key, key_for_collection = nil)
         @_key = key.to_sym
         @_key_for_collection = key_for_collection&.to_sym
       end
 
-      # Set key to true
+      # Set root key for collection
       #
-      # @deprecated Use {#root_key!} instead
-      def key!
-        Alba::Deprecation.warn '[DEPRECATION] `key!` is deprecated, use `root_key!` instead.'
+      # @param key [String, Symbol]
+      # @raise [NoMethodError] when key doesn't respond to `to_sym` method
+      def root_key_for_collection(key)
         @_key = true
-        @_key_for_collection = true
+        @_key_for_collection = key.to_sym
       end
 
       # Set root key to true
       def root_key!
         @_key = true
@@ -398,69 +435,60 @@
       # Set layout
       #
       # @params file [String] name of the layout file
       # @params inline [Proc] a proc returning JSON string or a Hash representing JSON
       def layout(file: nil, inline: nil)
-        @_layout = validated_file_layout(file) || validated_inline_layout(inline)
+        @_layout = Layout.new(file: file, inline: inline)
       end
 
-      def validated_file_layout(filename)
-        case filename
-        when String, nil then filename
-        else
-          raise ArgumentError, 'File layout must be a String representing filename'
-        end
-      end
-      private :validated_file_layout
-
-      def validated_inline_layout(inline_layout)
-        case inline_layout
-        when Proc, nil then inline_layout
-        else
-          raise ArgumentError, 'Inline layout must be a Proc returning a Hash or a String'
-        end
-      end
-      private :validated_inline_layout
-
-      # Delete attributes
-      # Use this DSL in child class to ignore certain attributes
-      #
-      # @param attributes [Array<String, Symbol>]
-      def ignoring(*attributes)
-        Alba::Deprecation.warn '`ignoring` is deprecated now. Instead please use `attributes` instance method to filter out attributes.'
-        attributes.each do |attr_name|
-          @_attributes.delete(attr_name.to_sym)
-        end
-      end
-
       # Transform keys as specified type
       #
       # @param type [String, Symbol] one of `snake`, `:camel`, `:lower_camel`, `:dash` and `none`
-      # @param root [Boolean, nil] decides if root key also should be transformed
-      #   When it's `nil`, Alba's default setting will be applied
+      # @param root [Boolean] decides if root key also should be transformed
+      # @param cascade [Boolean] decides if key transformation cascades into inline association
+      #   Default is true but can be set false for old (v1) behavior
       # @raise [Alba::Error] when type is not supported
-      def transform_keys(type, root: nil)
+      def transform_keys(type, root: true, cascade: true)
         type = type.to_sym
         unless %i[none snake camel lower_camel dash].include?(type)
           # This should be `ArgumentError` but for backward compatibility it raises `Alba::Error`
           raise ::Alba::Error, "Unknown transform type: #{type}. Supported type are :camel, :lower_camel and :dash."
         end
 
         @_transform_type = type
         @_transforming_root_key = root
+        @_key_transformation_cascade = cascade
       end
 
+      # Sets key for collection serialization
+      #
+      # @param key [String, Symbol]
+      def collection_key(key)
+        @_collection_key = key.to_sym
+      end
+
       # Set error handler
       # If this is set it's used as a error handler overriding global one
       #
       # @param handler [Symbol] `:raise`, `:ignore` or `:nullify`
       # @param block [Block]
       def on_error(handler = nil, &block)
         raise ArgumentError, 'You cannot specify error handler with both Symbol and block' if handler && block
         raise ArgumentError, 'You must specify error handler with either Symbol or block' unless handler || block
 
-        @_on_error = handler || block
+        @_on_error = block || validated_error_handler(handler)
       end
+
+      def validated_error_handler(handler)
+        unless %i[raise ignore nullify].include?(handler)
+          # For backward compatibility
+          # TODO: Change this to ArgumentError
+          raise Alba::Error, "Unknown error handler: #{handler}. It must be one of `:raise`, `:ignore` or `:nullify`."
+        end
+
+        handler
+      end
+      private :validated_error_handler
 
       # Set nil handler
       #
       # @param block [Block]
       def on_nil(&block)