Renderer - wip

lib/blueprinter/v2.rb

@@ -1,3 +1,19 @@
 # frozen_string_literal: true
 
 require 'blueprinter/v2/base'
+
+module Blueprinter
+  module V2
+    module Extensions
+      autoload :ConditionalFields, 'blueprinter/v2/extensions/conditional_fields'
+      autoload :DefaultValues, 'blueprinter/v2/extensions/default_values'
+      autoload :ExcludeIfNil, 'blueprinter/v2/extensions/exclude_if_nil'
+
+      DEFAULT = [
+        ConditionalFields,
+        DefaultValues,
+        ExcludeIfNil
+      ].freeze
+    end
+  end
+end

lib/blueprinter/v2/association.rb

@@ -9,6 +9,7 @@ module V2
       :legacy_view,
       :from,
       :value_proc,
+      :extractor,
       :options,
       keyword_init: true
     )

lib/blueprinter/v2/base.rb

@@ -2,6 +2,8 @@
 
 require 'blueprinter/v2/dsl'
 require 'blueprinter/v2/reflection'
+require 'blueprinter/v2/render'
+require 'blueprinter/v2/serializer'
 require 'blueprinter/v2/view_builder'
 
 module Blueprinter
@@ -12,10 +14,12 @@ class Base
       extend Reflection
 
       class << self
-        # Options set on this Blueprint
+        # Custom options set on this Blueprint for extensions
         attr_accessor :options
         # Extensions set on this Blueprint
         attr_accessor :extensions
+        # Extractor class to use by default
+        attr_accessor :extractor
         # @api private The fully-qualified name, e.g. "MyBlueprint", or "MyBlueprint.foo.bar"
         attr_accessor :blueprint_name
         # @api private
@@ -28,6 +32,7 @@ class << self
       self.partials = {}
       self.used_partials = []
       self.extensions = []
+      self.extractor = nil
       self.options = {}
       self.blueprint_name = name
       self.eval_mutex = Mutex.new
@@ -40,6 +45,7 @@ def self.inherited(subclass)
         subclass.partials = partials.dup
         subclass.used_partials = []
         subclass.extensions = extensions.dup
+        subclass.extractor = extractor
         subclass.options = options.dup
         subclass.blueprint_name = subclass.name || blueprint_name
         subclass.eval_mutex = Mutex.new
@@ -77,6 +83,7 @@ def self.[](name)
         children ? view[children] : view
       end
 
+      # MyBlueprint.render(obj).to_json
       def self.render(obj, options = {})
         if array_like? obj
           render_collection(obj, options)
@@ -85,12 +92,20 @@ def self.render(obj, options = {})
         end
       end
 
+      # MyBlueprint.render_object(obj).to_json
       def self.render_object(obj, options = {})
-        # TODO call external renderer
+        Render.new(obj, options, serializer: serializer, collection: false)
       end
 
+      # MyBlueprint.render_collection(objs).to_json
       def self.render_collection(objs, options = {})
-        # TODO call external renderer
+        Render.new(obj, options, serializer: serializer, collection: true)
+      end
+
+      # @api private
+      def self.serializer
+        eval! unless @evaled
+        @serializer
       end
 
       # Apply partials and field exclusions
@@ -115,6 +130,7 @@ def self.run_eval!
         end
 
         excludes.each { |f| fields.delete f }
+        @serializer = Serializer.new(self)
         @evaled = true
       end
 

lib/blueprinter/v2/dsl.rb

@@ -43,14 +43,16 @@ def use(*names)
       #
       # @param name [Symbol] Name of the field
       # @param from [Symbol] Optionally specify a different method to call to get the value for "name"
+      # @param extractor [Class] Extractor class to use for this field
       # @yield [TODO] Generate the value from the block
       # @return [Blueprinter::V2::Field]
       #
-      def field(name, from: name, **options, &definition)
+      def field(name, from: name, extractor: nil, **options, &definition)
         fields[name.to_sym] = Field.new(
           name: name,
           from: from,
           value_proc: definition,
+          extractor: extractor,
           options: options.dup
         )
       end
@@ -62,10 +64,11 @@ def field(name, from: name, **options, &definition)
       # @param blueprint [Class|Proc] Blueprint class to use, or one defined with a Proc
       # @param view [Symbol] Only for use with legacy (not V2) blueprints
       # @param from [Symbol] Optionally specify a different method to call to get the value for "name"
+      # @param extractor [Class] Extractor class to use for this association
       # @yield [TODO] Generate the value from the block
       # @return [Blueprinter::V2::Association]
       #
-      def object(name, blueprint, from: name, view: nil, **options, &definition)
+      def object(name, blueprint, from: name, view: nil, extractor: nil, **options, &definition)
         raise ArgumentError, 'The :view argument may not be used with V2 Blueprints' if view && blueprint.is_a?(V2)
 
         fields[name.to_sym] = Association.new(
@@ -75,6 +78,7 @@ def object(name, blueprint, from: name, view: nil, **options, &definition)
           legacy_view: view,
           from: from,
           value_proc: definition,
+          extractor: extractor,
           options: options.dup
         )
       end
@@ -86,10 +90,11 @@ def object(name, blueprint, from: name, view: nil, **options, &definition)
       # @param blueprint [Class|Proc] Blueprint class to use, or one defined with a Proc
       # @param view [Symbol] Only for use with legacy (not V2) blueprints
       # @param from [Symbol] Optionally specify a different method to call to get the value for "name"
+      # @param extractor [Class] Extractor class to use for this association
       # @yield [TODO] Generate the value from the block
       # @return [Blueprinter::V2::Association]
       #
-      def collection(name, blueprint, from: name, view: nil, **options, &definition)
+      def collection(name, blueprint, from: name, view: nil, extractor: nil, **options, &definition)
         raise ArgumentError, 'The :view argument may not be used with V2 Blueprints' if view && blueprint.is_a?(V2)
 
         fields[name.to_sym] = Association.new(
@@ -99,6 +104,7 @@ def collection(name, blueprint, from: name, view: nil, **options, &definition)
           legacy_view: view,
           from: from,
           value_proc: definition,
+          extractor: extractor,
           options: options.dup
         )
       end

lib/blueprinter/v2/extension.rb

@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+module Blueprinter
+  module V2
+    class Extension
+      class << self
+        attr_accessor :formatters
+      end
+
+      def self.inherited(ext)
+        ext.formatters = {}
+      end
+
+      #
+      # Add a formatter for instances of the given class.
+      #
+      # Example:
+      #   class MyExtension < Blueprinter::V2::Extension
+      #     format(Time) { |context| context.value.iso8601 }
+      #     format Date, :date_str
+      #
+      #     def date_str(context)
+      #       context.value.iso8601
+      #     end
+      #   end
+      #
+      # @param klass [Class] The class of objects to format
+      # @param formatter_method [Symbol] Name of a public instance method to call for formatting
+      # @yield Do formatting in the block instead
+      #
+      def self.format(klass, formatter_method = nil, &formatter_block)
+        formatters[klass] = formatter_method || formatter_block
+      end
+
+      # Returning true will exclude this field and value from the results
+      # @param _context [Blueprinter::V2::Serializer::Context]
+      # @return [Boolean]
+      def exclude_field?(_context)
+        false
+      end
+
+      # Returning true will exclude this association and value from the results
+      # @param _context [Blueprinter::V2::Serializer::Context]
+      # @return [Boolean]
+      def exclude_object?(_context)
+        false
+      end
+
+      # Returning true will exclude this association and value from the results
+      # @param _context [Blueprinter::V2::Serializer::Context]
+      # @return [Boolean]
+      def exclude_collection?(_context)
+        false
+      end
+
+      # @param context [Blueprinter::V2::Serializer::Context]
+      # @return [Object]
+      def field_value(context)
+        context.value
+      end
+
+      # @param context [Blueprinter::V2::Serializer::Context]
+      # @return [Object]
+      def object_value(context)
+        context.value
+      end
+
+      # @param context [Blueprinter::V2::Serializer::Context]
+      # @return [Object]
+      def collection_value(context)
+        context.value
+      end
+
+      # Modify or replace the object passed to render/render_object/render_collection
+      def input(_blueprint, object, _options)
+        object
+      end
+
+      # Modify or replace the result before final render (e.g. to JSON)
+      def output(_blueprint, result, _options)
+        result
+      end
+    end
+  end
+end

lib/blueprinter/v2/extensions/conditional_fields.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require 'blueprinter/v2/extension'
+
+module Blueprinter
+  module V2
+    module Extensions
+      class ConditionalFields < ::Blueprinter::V2::Extension
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def exclude_field?(ctx)
+          if (cond = ctx.options[:field_if] || ctx.field.options[:if] || ctx.blueprint.class.options[:field_if])
+            ctx.blueprint.instance_exec(ctx, &cond)
+          elsif (cond = ctx.options[:field_unless] || ctx.field.options[:unless] || ctx.blueprint.class.options[:field_unless])
+            !ctx.blueprint.instance_exec(ctx, &cond)
+          else
+            false
+          end
+        end
+
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def exclude_object?(ctx)
+          if (cond = ctx.options[:object_if] || ctx.field.options[:if] || ctx.blueprint.class.options[:object_if])
+            ctx.blueprint.instance_exec(ctx, &cond)
+          elsif (cond = ctx.options[:object_unless] || ctx.field.options[:unless] || ctx.blueprint.class.options[:object_unless])
+            !ctx.blueprint.instance_exec(ctx, &cond)
+          else
+            false
+          end
+        end
+
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def exclude_collection?(ctx)
+          if (cond = ctx.options[:collection_if] || ctx.field.options[:if] || ctx.blueprint.class.options[:collection_if])
+            ctx.blueprint.instance_exec(ctx, &cond)
+          elsif (cond = ctx.options[:collection_unless] || ctx.field.options[:unless] || ctx.blueprint.class.options[:collection_unless])
+            !ctx.blueprint.instance_exec(ctx, &cond)
+          else
+            false
+          end
+        end
+      end
+    end
+  end
+end

lib/blueprinter/v2/extensions/default_values.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require 'blueprinter/v2/extension'
+
+module Blueprinter
+  module V2
+    module Extensions
+      class DefaultValues < ::Blueprinter::V2::Extension
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def field_value(ctx)
+          default_if = ctx.options[:field_default_if] || ctx.field.options[:default_if] || ctx.blueprint.class.options[:field_default_if]
+          return ctx.value unless ctx.value.nil? || default_if&.call(ctx.value)
+
+          ctx.options[:field_default] || ctx.field.options[:default] || ctx.blueprint.class.options[:field_default]
+        end
+
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def object_value(ctx)
+          default_if = ctx.options[:object_default_if] || ctx.field.options[:default_if] || ctx.blueprint.class.options[:object_default_if]
+          return ctx.value unless ctx.value.nil? || default_if&.call(ctx.value)
+
+          ctx.options[:object_default] || ctx.field.options[:default] || ctx.blueprint.class.options[:object_default]
+        end
+
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def collection_value(ctx)
+          default_if = ctx.options[:collection_default_if] || ctx.field.options[:default_if] || ctx.blueprint.class.options[:collection_default_if]
+          return ctx.value unless ctx.value.nil? || default_if&.call(ctx.value)
+
+          ctx.options[:collection_default] || ctx.field.options[:default] || ctx.blueprint.class.options[:collection_default]
+        end
+      end
+    end
+  end
+end

lib/blueprinter/v2/extensions/exclude_if_nil.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'blueprinter/v2/extension'
+
+module Blueprinter
+  module V2
+    module Extensions
+      class ExcludeIfNil < Extension
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def exclude_field?(ctx)
+          ctx.value.nil? && (ctx.options[:exclude_if_nil] || ctx.field.options[:exclude_if_nil] || ctx.blueprint.class.options[:exclude_if_nil])
+        end
+
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def exclude_object?(...)
+          exclude_field?(...)
+        end
+
+        # @param ctx [Blueprinter::V2::Serializer::Context]
+        def exclude_collection?(...)
+          exclude_field?(...)
+        end
+      end
+    end
+  end
+end

lib/blueprinter/v2/extractor.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module Blueprinter
+  module V2
+    # The default extractor, and the suggested base class for custom extractors
+    class Extractor
+      def field(blueprint_instance, field, object, options)
+        if field.value_proc
+          blueprint_instance.instance_exec(object, options, &field.value_proc)
+        elsif object.is_a? Hash
+          object[field.from]
+        else
+          object.public_send(field.from)
+        end
+      end
+
+      def object(blueprint_instance, field, object, options)
+        field(blueprint_instance, field, object, options)
+      end
+
+      def collection(blueprint_instance, field, object, options)
+        field(blueprint_instance, field, object, options)
+      end
+    end
+  end
+end

lib/blueprinter/v2/field.rb

@@ -6,6 +6,7 @@ module V2
       :name,
       :from,
       :value_proc,
+      :extractor,
       :options,
       keyword_init: true
     )