lib/alba/resource.rb in alba-1.5.0 vs lib/alba/resource.rb in alba-1.6.0

@@ -1,17 +1,15 @@
-require_relative 'one'
-require_relative 'many'
-require_relative 'key_transform_factory'
+require_relative 'association'
 require_relative 'typed_attribute'
 require_relative 'deprecation'
 
 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_key_function: nil, _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}.freeze # rubocop:disable Layout/LineLength
     private_constant :DSLS
 
     WITHIN_DEFAULT = Object.new.freeze
     private_constant :WITHIN_DEFAULT
 
@@ -37,10 +35,11 @@
       # @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
         @within = within
+        @method_existence = {} # Cache for `respond_to?` result
         DSLS.each_key { |name| instance_variable_set("@#{name}", self.class.public_send(name)) }
       end
 
       # Serialize object into JSON string
       #
@@ -65,37 +64,54 @@
       #
       # @return [Hash]
       def serializable_hash
         collection? ? @object.map(&converter) : converter.call(@object)
       end
-      alias to_hash serializable_hash
+      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 serialize_with(hash)
-        @serialized_json = encode(hash)
-        case @_layout
-        when String # file
+        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)
-        when Proc # inline
-          inline = instance_eval(&@_layout)
-          inline.is_a?(Hash) ? encode(inline) : inline
-        else # no layout
-          @serialized_json
+
+        else # inline
+          serialize_within_inline_layout
         end
       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)
-        base = @_meta ? instance_eval(&@_meta) : {}
-        metadata = base.merge(meta)
-        hash[:meta] = metadata unless metadata.empty?
+        return hash if meta.empty? && @_meta.nil?
+
+        metadata = @_meta ? instance_eval(&@_meta).merge(meta) : meta
+        hash[:meta] = metadata
         hash
       end
 
       def fetch_key
         collection? ? _key_for_collection : _key
@@ -114,30 +130,39 @@
 
         transforming_root_key? ? transform_key(resource_name) : resource_name
       end
 
       def resource_name
-        self.class.name.demodulize.delete_suffix('Resource').underscore
+        @resource_name ||= self.class.name.demodulize.delete_suffix('Resource').underscore
       end
 
       def transforming_root_key?
         @_transforming_root_key.nil? ? Alba.transforming_root_key : @_transforming_root_key
       end
 
+      # rubocop:disable Metrics/MethodLength
       def converter
         lambda do |object|
-          arrays = @_attributes.map do |key, attribute|
+          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.reject(&:empty?).to_h
+          arrays.compact!
+          arrays.to_h
         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
@@ -156,56 +181,76 @@
       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)
+        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)
+        return if arity >= 2 && !instance_exec(object, attr, &condition)
 
         [key, fetched_attribute]
       end
 
       def conditional_attribute_with_symbol(object, key, attribute, condition)
-        return [] unless __send__(condition)
+        return unless __send__(condition)
 
         [key, fetch_attribute(object, key, attribute)]
       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]
-        when :ignore then []
+        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}"
         end
       end
 
-      # Override this method to supply custom key transform method
+      # rubocop:disable Metrics/MethodLength
+      # @return [Symbol]
       def transform_key(key)
-        return key if @_transform_key_function.nil?
+        return key if @_transform_type == :none
 
-        @_transform_key_function.call(key.to_s)
+        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
+        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
+      # rubocop:enable Metrics/MethodLength
 
       def fetch_attribute(object, key, attribute)
         value = case attribute
-                when Symbol then object.public_send attribute
+                when Symbol then fetch_attribute_from_object_and_resource(object, attribute)
                 when Proc then instance_exec(object, &attribute)
-                when Alba::One, Alba::Many then yield_if_within(attribute.name.to_sym) { |within| attribute.to_hash(object, params: params, within: within) }
+                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)
                 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)
+      end
+
       def nil_handler
         @nil_handler ||= (@_on_nil || Alba._on_nil)
       end
 
       def yield_if_within(association_name)
@@ -223,12 +268,14 @@
         else
           raise Alba::Error, "Unknown type for within option: #{@within.class}"
         end
       end
 
+      # Detect if object is a collection or not.
+      # When object is a Struct, it's Enumerable but not a collection
       def collection?
-        @object.is_a?(Enumerable)
+        @object.is_a?(Enumerable) && !@object.is_a?(Struct)
       end
     end
 
     # Class methods
     module ClassMethods
@@ -239,11 +286,10 @@
         super
         DSLS.each_key { |name| subclass.instance_variable_set("@#{name}", instance_variable_get("@#{name}").clone) }
       end
 
       # Defining methods for DSLs and disable parameter number check since for users' benefits increasing params is fine
-      # rubocop:disable Metrics/ParameterLists
 
       # Set multiple attributes at once
       #
       # @param attrs [Array<String, Symbol>]
       # @param if [Proc] condition to decide if it should serialize these attributes
@@ -287,46 +333,31 @@
         raise ArgumentError, 'No block given in attribute method' unless block
 
         @_attributes[name.to_sym] = options[:if] ? [block, options[:if]] : block
       end
 
-      # Set One association
+      # 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 key [String, Symbol, nil] used as key when given
       # @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::One#initialize
-      def one(name, condition = nil, resource: nil, key: nil, **options, &block)
+      # @see Alba::Association#initialize
+      def association(name, condition = nil, resource: nil, key: nil, **options, &block)
         nesting = self.name&.rpartition('::')&.first
-        one = One.new(name: name, condition: condition, resource: resource, nesting: nesting, &block)
-        @_attributes[key&.to_sym || name.to_sym] = options[:if] ? [one, options[:if]] : one
+        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
       end
-      alias has_one one
+      alias one association
+      alias many association
+      alias has_one association
+      alias has_many association
 
-      # Set Many 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 filter the collection
-      # @param resource [Class<Alba::Resource>, String, nil] representing resource for this association
-      # @param key [String, Symbol, nil] used as key when given
-      # @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::Many#initialize
-      def many(name, condition = nil, resource: nil, key: nil, **options, &block)
-        nesting = self.name&.rpartition('::')&.first
-        many = Many.new(name: name, condition: condition, resource: resource, nesting: nesting, &block)
-        @_attributes[key&.to_sym || name.to_sym] = options[:if] ? [many, options[:if]] : many
-      end
-      alias has_many many
-
       # Set key
       #
       # @param key [String, Symbol]
       # @deprecated Use {#root_key} instead
       def key(key)
@@ -367,29 +398,56 @@
       # 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 = file || inline
+        @_layout = validated_file_layout(file) || validated_inline_layout(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]
-      # @param root [Boolean] decides if root key also should be transformed
+      # @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
+      # @raise [Alba::Error] when type is not supported
       def transform_keys(type, root: nil)
-        @_transform_key_function = KeyTransformFactory.create(type.to_sym)
+        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
       end
 
       # Set error handler
       # If this is set it's used as a error handler overriding global one
@@ -407,10 +465,8 @@
       #
       # @param block [Block]
       def on_nil(&block)
         @_on_nil = block
       end
-
-      # rubocop:enable Metrics/ParameterLists
     end
   end
 end