Refactor Builder using modules

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- Split `Form::Builder` into modules, to allow including only some modules instead of inheriting the whole class (#134)
+
 ### Fixed
 - Update dependencies (#128)
 - Add Ruby 3.2 to CI (#128)

README.md

@@ -100,7 +100,7 @@ This allows you to pick the namespace your components will be loaded from.
 # lib/custom_form_builder.rb
 class CustomFormBuilder < ViewComponent::Form::Builder
   # Set the namespace you want to use for your own components
-  namespace Custom::Form
+  namespace "Custom::Form"
 end
 ```
 
@@ -116,7 +116,32 @@ bin/rails generate vcf:builder AnotherCustomFormBuilder --namespace AnotherCusto
 # app/forms/another_custom_form_builder.rb
 class AnotherCustomFormBuilder < ViewComponent::Form::Builder
   # Set the namespace you want to use for your own components
-  namespace AnotherCustom::Form
+  namespace "AnotherCustom::Form"
+end
+```
+
+Another approach is to include only some modules instead of inheriting from the whole class:
+
+```rb
+# app/forms/modular_custom_form_builder.rb
+class ModularCustomFormBuilder < ActionView::Helpers::FormBuilder
+  # Provides `render_component` method and namespace management
+  include ViewComponent::Form::Renderer
+
+  # Exposes a `validation_context` to your components
+  include ViewComponent::Form::ValidationContext
+
+  # All standard Rails form helpers
+  include ViewComponent::Form::Helpers::Rails
+
+  # Backports of newest Rails form helpers
+  # include ViewComponent::Form::Helpers::RailsBackports
+
+  # Additional form helpers provided by ViewComponent::Form
+  # include ViewComponent::Form::Helpers::Custom
+
+  # Set the namespace you want to use for your own components
+  namespace "AnotherCustom::Form"
 end
 ```
 

lib/generators/vcf/builder/templates/builder.rb.erb

@@ -1,6 +1,27 @@
 # frozen_string_literal: true
 
 class <%= class_name %> < ViewComponent::Form::Builder
+  # Instead of inheriting from ViewComponent::Form::Builder,
+  # you can also inherit from ActionView::Helpers::FormBuilder
+  # then include only the modules you need:
+
+  # Provides `render_component` method and namespace management
+  # include ViewComponent::Form::Renderer
+
+  # Exposes a `validation_context` to your components
+  # include ViewComponent::Form::ValidationContext
+
+  # All standard Rails form helpers
+  # include ViewComponent::Form::Helpers::Rails
+
+  # Backports of newest Rails form helpers
+  # include ViewComponent::Form::Helpers::RailsBackports
+
+  # Additional form helpers provided by ViewComponent::Form
+  # include ViewComponent::Form::Helpers::Custom
+
   # Set the namespace you want to use for your own components
+  # requires inheriting from ViewComponent::Form::Builder
+  # or including ViewComponent::Form::Renderer
   namespace "<%= components_namespace %>"
 end

lib/view_component/form/builder.rb

@@ -3,246 +3,11 @@
 module ViewComponent
   module Form
     class Builder < ActionView::Helpers::FormBuilder
-      class Error < StandardError; end
-
-      class NotImplementedComponentError < Error; end
-
-      class NamespaceAlreadyAddedError < Error; end
-
-      class_attribute :lookup_namespaces, default: [ViewComponent::Form]
-
-      class << self
-        def inherited(base)
-          base.lookup_namespaces = lookup_namespaces.dup
-
-          super
-        end
-
-        def namespace(namespace)
-          if lookup_namespaces.include?(namespace)
-            raise NamespaceAlreadyAddedError, "The component namespace '#{namespace}' is already added"
-          end
-
-          lookup_namespaces.prepend namespace
-        end
-      end
-
-      attr_reader :validation_context
-
-      def initialize(*)
-        @__component_klass_cache = {}
-
-        super
-
-        @validation_context = options[:validation_context]
-      end
-
-      (field_helpers - %i[
-        check_box
-        datetime_field
-        datetime_local_field
-        fields
-        fields_for
-        file_field
-        hidden_field
-        label
-        phone_field
-        radio_button
-      ]).each do |selector|
-        class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1
-          def #{selector}(method, options = {}) # def text_field(method, options = {})
-            render_component(                   #   render_component(
-              :#{selector},                     #     :text_field,
-              @object_name,                     #     @object_name,
-              method,                           #     method,
-              objectify_options(options),       #     objectify_options(options),
-            )                                   #   )
-          end                                   # end
-        RUBY_EVAL
-      end
-      alias phone_field telephone_field
-
-      # See: https://github.com/rails/rails/blob/33d60cb02dcac26d037332410eabaeeb0bdc384c/actionview/lib/action_view/helpers/form_helper.rb#L2280
-      def label(method, text = nil, options = {}, &block)
-        render_component(:label, @object_name, method, text, objectify_options(options), &block)
-      end
-
-      def datetime_field(method, options = {})
-        render_component(
-          :datetime_local_field, @object_name, method, objectify_options(options)
-        )
-      end
-      alias datetime_locale_field datetime_field
-
-      def check_box(method, options = {}, checked_value = "1", unchecked_value = "0")
-        render_component(
-          :check_box, @object_name, method, checked_value, unchecked_value, objectify_options(options)
-        )
-      end
-
-      def radio_button(method, tag_value, options = {})
-        render_component(
-          :radio_button, @object_name, method, tag_value, objectify_options(options)
-        )
-      end
-
-      def file_field(method, options = {})
-        self.multipart = true
-        render_component(:file_field, @object_name, method, objectify_options(options))
-      end
-
-      def submit(value = nil, options = {})
-        if value.is_a?(Hash)
-          options = value
-          value = nil
-        end
-        value ||= submit_default_value
-        render_component(:submit, value, options)
-      end
-
-      def button(value = nil, options = {}, &block)
-        if value.is_a?(Hash)
-          options = value
-          value = nil
-        end
-        value ||= submit_default_value
-        render_component(:button, value, options, &block)
-      end
-
-      # See: https://github.com/rails/rails/blob/fe76a95b0d252a2d7c25e69498b720c96b243ea2/actionview/lib/action_view/helpers/form_options_helper.rb
-      def select(method, choices = nil, options = {}, html_options = {}, &block)
-        render_component(
-          :select, @object_name, method, choices, objectify_options(options),
-          @default_html_options.merge(html_options), &block
-        )
-      end
-
-      # rubocop:disable Metrics/ParameterLists
-      def collection_select(method, collection, value_method, text_method, options = {}, html_options = {})
-        render_component(
-          :collection_select, @object_name, method, collection, value_method, text_method,
-          objectify_options(options), @default_html_options.merge(html_options)
-        )
-      end
-
-      def grouped_collection_select(
-        method, collection,
-        group_method, group_label_method, option_key_method, option_value_method,
-        options = {}, html_options = {}
-      )
-        render_component(
-          :grouped_collection_select, @object_name, method, collection, group_method,
-          group_label_method, option_key_method, option_value_method,
-          objectify_options(options), @default_html_options.merge(html_options)
-        )
-      end
-
-      def collection_check_boxes(method, collection, value_method, text_method, options = {}, html_options = {}, &block)
-        render_component(
-          :collection_check_boxes, @object_name, method, collection, value_method, text_method,
-          objectify_options(options), @default_html_options.merge(html_options), &block
-        )
-      end
-
-      def collection_radio_buttons(
-        method, collection,
-        value_method, text_method,
-        options = {}, html_options = {},
-        &block
-      )
-        render_component(
-          :collection_radio_buttons, @object_name, method, collection, value_method, text_method,
-          objectify_options(options), @default_html_options.merge(html_options), &block
-        )
-      end
-      # rubocop:enable Metrics/ParameterLists
-
-      def date_select(method, options = {}, html_options = {})
-        render_component(
-          :date_select, @object_name, method,
-          objectify_options(options), @default_html_options.merge(html_options)
-        )
-      end
-
-      def datetime_select(method, options = {}, html_options = {})
-        render_component(
-          :datetime_select, @object_name, method,
-          objectify_options(options), @default_html_options.merge(html_options)
-        )
-      end
-
-      def time_select(method, options = {}, html_options = {})
-        render_component(
-          :time_select, @object_name, method,
-          objectify_options(options), @default_html_options.merge(html_options)
-        )
-      end
-
-      def time_zone_select(method, priority_zones = nil, options = {}, html_options = {})
-        render_component(
-          :time_zone_select, @object_name, method, priority_zones,
-          objectify_options(options), @default_html_options.merge(html_options)
-        )
-      end
-
-      if defined?(ActionView::Helpers::Tags::ActionText)
-        def rich_text_area(method, options = {})
-          render_component(:rich_text_area, @object_name, method, objectify_options(options))
-        end
-      end
-
-      def error_message(method, options = {})
-        render_component(:error_message, @object_name, method, objectify_options(options))
-      end
-
-      def hint(method, text = nil, options = {}, &block)
-        render_component(:hint, @object_name, method, text, objectify_options(options), &block)
-      end
-
-      # Backport field_id from Rails 7.0
-      if Rails::VERSION::MAJOR < 7
-        def field_id(method_name, *suffixes, namespace: @options[:namespace], index: @index)
-          object_name = object_name.model_name.singular if object_name.respond_to?(:model_name)
-
-          sanitized_object_name = object_name.to_s.gsub(/\]\[|[^-a-zA-Z0-9:.]/, "_").delete_suffix("_")
-
-          sanitized_method_name = method_name.to_s.delete_suffix("?")
-
-          [
-            namespace,
-            sanitized_object_name.presence,
-            (index unless sanitized_object_name.empty?),
-            sanitized_method_name,
-            *suffixes
-          ].tap(&:compact!).join("_")
-        end
-      end
-
-      private
-
-      def render_component(component_name, *args, &block)
-        component = component_klass(component_name).new(self, *args)
-        component.render_in(@template, &block)
-      end
-
-      def objectify_options(options)
-        @default_options.merge(options.merge(object: @object))
-      end
-
-      def component_klass(component_name)
-        @__component_klass_cache[component_name] ||= begin
-          component_klass = self.class.lookup_namespaces.filter_map do |namespace|
-            "#{namespace}::#{component_name.to_s.camelize}Component".safe_constantize || false
-          end.first
-
-          unless component_klass.is_a?(Class) && component_klass < ViewComponent::Base
-            raise NotImplementedComponentError, "Component named #{component_name} doesn't exist " \
-                                                "or is not a ViewComponent::Base class"
-          end
-
-          component_klass
-        end
-      end
+      include ViewComponent::Form::Renderer
+      include ViewComponent::Form::ValidationContext
+      include ViewComponent::Form::Helpers::Rails
+      include ViewComponent::Form::Helpers::RailsBackports
+      include ViewComponent::Form::Helpers::Custom
     end
   end
 end

lib/view_component/form/helpers/custom.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module ViewComponent
+  module Form
+    module Helpers
+      module Custom
+        def error_message(method, options = {})
+          render_component(:error_message, @object_name, method, objectify_options(options))
+        end
+
+        def hint(method, text = nil, options = {}, &block)
+          render_component(:hint, @object_name, method, text, objectify_options(options), &block)
+        end
+      end
+    end
+  end
+end