Merge pull request #501 from github/bmw/compiler

Extract template compiler from base

Author: joelhawksley

lib/view_component.rb

@@ -6,6 +6,7 @@ module ViewComponent
   extend ActiveSupport::Autoload
 
   autoload :Base
+  autoload :Compiler
   autoload :Preview
   autoload :PreviewTemplateError
   autoload :TestHelpers

lib/view_component/base.rb

@@ -77,7 +77,7 @@ def render_in(view_context, &block)
       before_render
 
       if render?
-        send(self.class.call_method_name(@variant))
+        render_template_for(@variant)
       else
         ""
       end
@@ -208,80 +208,20 @@ def inherited(child)
         super
       end
 
-      def call_method_name(variant)
-        if variant.present? && variants.include?(variant)
-          "call_#{variant}"
-        else
-          "call"
-        end
-      end
-
       def compiled?
-        CompileCache.compiled?(self)
+        template_compiler.compiled?
       end
 
       # Compile templates to instance methods, assuming they haven't been compiled already.
       #
       # Do as much work as possible in this step, as doing so reduces the amount
       # of work done each time a component is rendered.
       def compile(raise_errors: false)
-        return if compiled?
-
-        if template_errors.present?
-          raise ViewComponent::TemplateError.new(template_errors) if raise_errors
-          return false
-        end
-
-        if instance_methods(false).include?(:before_render_check)
-          ActiveSupport::Deprecation.warn(
-            "`before_render_check` will be removed in v3.0.0. Use `before_render` instead."
-          )
-        end
-
-        # Remove any existing singleton methods,
-        # as Ruby warns when redefining a method.
-        remove_possible_singleton_method(:variants)
-        remove_possible_singleton_method(:collection_parameter)
-        remove_possible_singleton_method(:collection_counter_parameter)
-        remove_possible_singleton_method(:counter_argument_present?)
-
-        define_singleton_method(:variants) do
-          templates.map { |template| template[:variant] } + variants_from_inline_calls(inline_calls)
-        end
-
-        define_singleton_method(:collection_parameter) do
-          if provided_collection_parameter
-            provided_collection_parameter
-          else
-            name.demodulize.underscore.chomp("_component").to_sym
-          end
-        end
-
-        define_singleton_method(:collection_counter_parameter) do
-          "#{collection_parameter}_counter".to_sym
-        end
-
-        define_singleton_method(:counter_argument_present?) do
-          instance_method(:initialize).parameters.map(&:second).include?(collection_counter_parameter)
-        end
-
-        validate_collection_parameter! if raise_errors
-
-        templates.each do |template|
-          # Remove existing compiled template methods,
-          # as Ruby warns when redefining a method.
-          method_name = call_method_name(template[:variant])
-          undef_method(method_name.to_sym) if instance_methods.include?(method_name.to_sym)
-
-          class_eval <<-RUBY, template[:path], -1
-            def #{method_name}
-              @output_buffer = ActionView::OutputBuffer.new
-              #{compiled_template(template[:path])}
-            end
-          RUBY
-        end
+        template_compiler.compile(raise_errors: raise_errors)
+      end
 
-        CompileCache.register self
+      def template_compiler
+        @_template_compiler ||= Compiler.new(self)
       end
 
       # we'll eventually want to update this to support other types
@@ -346,111 +286,6 @@ def provided_collection_parameter
         @provided_collection_parameter ||= nil
       end
 
-      def compiled_template(file_path)
-        handler = ActionView::Template.handler_for_extension(File.extname(file_path).gsub(".", ""))
-        template = File.read(file_path)
-
-        if handler.method(:call).parameters.length > 1
-          handler.call(self, template)
-        else
-          handler.call(OpenStruct.new(source: template, identifier: identifier, type: type))
-        end
-      end
-
-      def inline_calls
-        @inline_calls ||=
-          begin
-            # Fetch only ViewComponent ancestor classes to limit the scope of
-            # finding inline calls
-            view_component_ancestors =
-              ancestors.take_while { |ancestor| ancestor != ViewComponent::Base } - included_modules
-
-            view_component_ancestors.flat_map { |ancestor| ancestor.instance_methods(false).grep(/^call/) }.uniq
-          end
-      end
-
-      def inline_calls_defined_on_self
-        @inline_calls_defined_on_self ||= instance_methods(false).grep(/^call/)
-      end
-
-      def matching_views_in_source_location
-        return [] unless source_location
-
-        location_without_extension = source_location.chomp(File.extname(source_location))
-
-        extensions = ActionView::Template.template_handler_extensions.join(",")
-
-        # view files in the same directory as the component
-        sidecar_files = Dir["#{location_without_extension}.*{#{extensions}}"]
-
-        # view files in a directory named like the component
-        directory = File.dirname(source_location)
-        filename = File.basename(source_location, ".rb")
-        component_name = name.demodulize.underscore
-
-        sidecar_directory_files = Dir["#{directory}/#{component_name}/#{filename}.*{#{extensions}}"]
-
-        (sidecar_files - [source_location] + sidecar_directory_files)
-      end
-
-      def templates
-        @templates ||=
-          matching_views_in_source_location.each_with_object([]) do |path, memo|
-            pieces = File.basename(path).split(".")
-
-            memo << {
-              path: path,
-              variant: pieces.second.split("+").second&.to_sym,
-              handler: pieces.last
-            }
-          end
-      end
-
-      def template_errors
-        @template_errors ||=
-          begin
-            errors = []
-
-            if (templates + inline_calls).empty?
-              errors << "Could not find a template file or inline render method for #{self}."
-            end
-
-            if templates.count { |template| template[:variant].nil? } > 1
-              errors << "More than one template found for #{self}. There can only be one default template file per component."
-            end
-
-            invalid_variants = templates
-                                  .group_by { |template| template[:variant] }
-                                  .map { |variant, grouped| variant if grouped.length > 1 }
-                                  .compact
-                                  .sort
-
-            unless invalid_variants.empty?
-              errors << "More than one template found for #{'variant'.pluralize(invalid_variants.count)} #{invalid_variants.map { |v| "'#{v}'" }.to_sentence} in #{self}. There can only be one template file per variant."
-            end
-
-            if templates.find { |template| template[:variant].nil? } && inline_calls_defined_on_self.include?(:call)
-              errors << "Template file and inline render method found for #{self}. There can only be a template file or inline render method per component."
-            end
-
-            duplicate_template_file_and_inline_variant_calls =
-              templates.pluck(:variant) & variants_from_inline_calls(inline_calls_defined_on_self)
-
-            unless duplicate_template_file_and_inline_variant_calls.empty?
-              count = duplicate_template_file_and_inline_variant_calls.count
-
-              errors << "Template #{'file'.pluralize(count)} and inline render #{'method'.pluralize(count)} found for #{'variant'.pluralize(count)} #{duplicate_template_file_and_inline_variant_calls.map { |v| "'#{v}'" }.to_sentence} in #{self}. There can only be a template file or inline render method per variant."
-            end
-
-            errors
-          end
-      end
-
-      def variants_from_inline_calls(calls)
-        calls.reject { |call| call == :call }.map do |variant_call|
-          variant_call.to_s.sub("call_", "").to_sym
-        end
-      end
     end
 
     ActiveSupport.run_load_hooks(:view_component, self)