Remove the global output buffer; compile on render_in (#1432)

* Remove the global output buffer; compile on render_in

* Use rails main

* Fix linting issues

* Fix bad merge

Co-authored-by: Joel Hawksley <[email protected]>

Author: camertron

.github/workflows/ci.yml

@@ -29,7 +29,6 @@ jobs:
       matrix:
         rails_version: ['5.2.6', '6.0.4.4', '6.1.4.4', '7.0.2.3', 'main']
         ruby_version: ['2.5', '2.6', '2.7', '3.0', '3.1']
-        output_buffer: ['global_buffer', 'local_buffer']
         exclude:
           - rails_version: '5.2.6'
             ruby_version: '3.0'
@@ -66,7 +65,6 @@ jobs:
         RAISE_ON_WARNING: 1
         MEASURE_COVERAGE: true
         RAILS_VERSION: ${{ matrix.rails_version }}
-        VIEW_COMPONENT_USE_GLOBAL_OUTPUT_BUFFER: ${{ matrix.output_buffer == 'global_buffer' && 'true' || 'false' }}
     - name: Upload coverage results
       uses: actions/upload-artifact@master
       if: always()

Gemfile

@@ -6,11 +6,7 @@ gemspec
 rails_version = (ENV["RAILS_VERSION"] || "~> 7.0.0").to_s
 
 gem "capybara", "~> 3"
-
-# https://github.com/rails/rails/pull/45614 broke our global output buffer
-# code, which we plan to remove anyways. Pinning to before it was merged
-# so CI will work.
-gem "rails", rails_version == "main" ? {git: "https://github.com/rails/rails", ref: "71c59c69f40cef908d0a97ef4b4c5496778559e5"} : rails_version
+gem "rails", rails_version == "main" ? {git: "https://github.com/rails/rails", ref: "main"} : rails_version
 
 gem "rspec-rails", "~> 5"
 

docs/CHANGELOG.md

@@ -9,6 +9,12 @@ title: Changelog
 
 ## main
 
+* Remove the experimental global output buffer feature.
+* Restore functionality that used to attempt to compile templates on each call to `#render_in`.
+* Un-pin `rails` `main` dependency.
+
+    *Cameron Dutro*
+
 * Add blank space between "in" and "ViewComponent" in a deprecation warning.
 
     *Vikram Dighe*

docs/known_issues.md

@@ -9,28 +9,6 @@ title: Known issues
 
 ViewComponent [isn't compatible](https://github.com/github/view_component/issues/241) with `form_for` helpers by default.
 
-### Using a Global Output Buffer
-
-Since 2.52.0
-{: .label }
-
-Experimental
-{: .label .label-yellow }
-
-One possible solution to the form helpers problem is to use a single, global output buffer. For details, please refer to [this pull request](https://github.com/github/view_component/pull/1307).
-
-The global output buffer behavior is opt-in. Prepend the `ViewComponent::GlobalOutputBuffer` module into individual component classes to use it.
-
-For example:
-
-```ruby
-class MyComponent < ViewComponent::Base
-  prepend ViewComponent::GlobalOutputBuffer
-end
-```
-
-It is also possible to enable the global output buffer globally by setting the `config.view_component.use_global_output_buffer` setting to `true` in your Rails config.
-
 ## Inconsistent controller rendering behavior between Rails versions
 
 In versions of Rails < 6.1, rendering a ViewComponent from a controller doesn't include the layout.

lib/view_component.rb

@@ -11,9 +11,7 @@ module ViewComponent
   autoload :CompileCache
   autoload :ComponentError
   autoload :Deprecation
-  autoload :GlobalOutputBuffer
   autoload :Instrumentation
-  autoload :OutputBufferStack
   autoload :Preview
   autoload :PreviewTemplateError
   autoload :TestHelpers

lib/view_component/base.rb

@@ -86,10 +86,12 @@ def self._deprecated_generate_mattr_accessor(name)
     #
     # @return [String]
     def render_in(view_context, &block)
+      self.class.compile(raise_errors: true)
+
       @view_context = view_context
       self.__vc_original_view_context ||= view_context
 
-      @output_buffer = ActionView::OutputBuffer.new unless defined?(@global_buffer_in_use) && @global_buffer_in_use
+      @output_buffer = ActionView::OutputBuffer.new
 
       @lookup_context ||= view_context.lookup_context
 
@@ -124,19 +126,14 @@ def render_in(view_context, &block)
       before_render
 
       if render?
-        perform_render
+        render_template_for(@__vc_variant).to_s + _output_postamble
       else
         ""
       end
     ensure
       @current_template = old_current_template
     end
 
-    # @private
-    def perform_render
-      render_template_for(@__vc_variant).to_s + _output_postamble
-    end
-
     # Subclass components that call `super` inside their template code will cause a
     # double render if they emit the result:
     #
@@ -152,17 +149,6 @@ def render_parent
       nil
     end
 
-    # @private
-    # :nocov:
-    def render_template_for(variant = nil)
-      # Force compilation here so the compiler always redefines render_template_for.
-      # This is mostly a safeguard to prevent infinite recursion.
-      self.class.compile(raise_errors: true, force: true)
-      # .compile replaces this method; call the new one
-      render_template_for(variant)
-    end
-    # :nocov:
-
     # EXPERIMENTAL: Optional content to be returned after the rendered template.
     #
     # @return [String]

lib/view_component/compile_cache.rb

@@ -20,11 +20,10 @@ def compiled?(klass)
 
     def invalidate_class!(klass)
       cache.delete(klass)
-      klass.compiler.reset_render_template_for
     end
 
     def invalidate!
-      cache.each { |klass| invalidate_class!(klass) }
+      cache.clear
     end
   end
 end

lib/view_component/compiler.rb

@@ -34,6 +34,8 @@ def compile(raise_errors: false, force: false)
       component_class.superclass.compile(raise_errors: raise_errors) if should_compile_superclass?
 
       with_lock do
+        CompileCache.invalidate_class!(component_class)
+
         subclass_instance_methods = component_class.instance_methods(false)
 
         if subclass_instance_methods.include?(:with_content) && raise_errors
@@ -66,8 +68,8 @@ def compile(raise_errors: false, force: false)
           # as Ruby warns when redefining a method.
           method_name = call_method_name(template[:variant])
 
-          if component_class.instance_methods(false).include?(method_name.to_sym)
-            component_class.send(:remove_method, method_name.to_sym)
+          if component_class.instance_methods.include?(method_name.to_sym)
+            component_class.send(:undef_method, method_name.to_sym)
           end
 
           # rubocop:disable Style/EvalWithLocation
@@ -96,18 +98,14 @@ def with_lock(&block)
       end
     end
 
-    def reset_render_template_for
-      if component_class.instance_methods(false).include?(:render_template_for)
-        component_class.send(:remove_method, :render_template_for)
-      end
-    end
-
     private
 
     attr_reader :component_class
 
     def define_render_template_for
-      reset_render_template_for
+      if component_class.instance_methods.include?(:render_template_for)
+        component_class.send(:undef_method, :render_template_for)
+      end
 
       variant_elsifs = variants.compact.uniq.map do |variant|
         "elsif variant.to_sym == :#{variant}\n    #{call_method_name(variant)}"

lib/view_component/engine.rb

@@ -20,7 +20,6 @@ class Engine < Rails::Engine # :nodoc:
       options.instrumentation_enabled = false if options.instrumentation_enabled.nil?
       options.preview_route ||= ViewComponent::Base.preview_route
       options.preview_controller ||= ViewComponent::Base.preview_controller
-      options.use_global_output_buffer = false if options.use_global_output_buffer.nil?
 
       if options.show_previews
         options.preview_paths << "#{Rails.root}/test/components/previews" if defined?(Rails.root) && Dir.exist?(
@@ -58,21 +57,6 @@ class Engine < Rails::Engine # :nodoc:
       end
     end
 
-    initializer "view_component.enable_global_output_buffer" do |app|
-      ActiveSupport.on_load(:view_component) do
-        env_use_gob = ENV.fetch("VIEW_COMPONENT_USE_GLOBAL_OUTPUT_BUFFER", "false") == "true"
-        config_use_gob = app.config.view_component.use_global_output_buffer
-
-        if config_use_gob || env_use_gob
-          # :nocov:
-          app.config.view_component.use_global_output_buffer = true
-          ViewComponent::Base.prepend(ViewComponent::GlobalOutputBuffer)
-          ActionView::Base.prepend(ViewComponent::GlobalOutputBuffer::ActionViewMods)
-          # :nocov:
-        end
-      end
-    end
-
     initializer "view_component.set_autoload_paths" do |app|
       options = app.config.view_component