Remove dependency on ActionView::Base, eliminating the need for capture compatibility patch. (#2287)

* Remove dependency on ActionView::Base, eliminating the need for capture compatibility patch.

Co-authored-by: Cameron Dutro <camertron@gmail.com>

* Use later version of Rails 7.1 for PVC integration tests

* docs updates

---------

Co-authored-by: Cameron Dutro <camertron@gmail.com>

Author: joelhawksley

.github/workflows/ci.yml

@@ -23,42 +23,20 @@ jobs:
         bundle exec appraisal rails-8.0 rake partial_benchmark
         bundle exec appraisal rails-8.0 rake translatable_benchmark
   test:
-    name: test (${{ matrix.rails_version }}, ${{ matrix.ruby_version }}, ${{ matrix.mode }})
+    name: test (Rails ${{ matrix.rails_version }}, Ruby ${{ matrix.ruby_version }})
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
         include:
           - ruby_version: "3.2"
             rails_version: "7.1"
-            mode: "capture_patch_enabled"
-          - ruby_version: "3.2"
-            rails_version: "7.1"
-            mode: "capture_patch_disabled"
-          - ruby_version: "3.3"
-            rails_version: "7.2"
-            mode: "capture_patch_disabled"
           - ruby_version: "3.3"
             rails_version: "7.2"
-            mode: "capture_patch_enabled"
-          - ruby_version: "3.3"
-            rails_version: "8.0"
-            mode: "capture_patch_disabled"
-          - ruby_version: "3.3"
-            rails_version: "8.0"
-            mode: "capture_patch_enabled"
-          - ruby_version: "3.4"
-            rails_version: "8.0"
-            mode: "capture_patch_disabled"
           - ruby_version: "3.4"
             rails_version: "8.0"
-            mode: "capture_patch_enabled"
-          - ruby_version: "head"
-            rails_version: "main"
-            mode: "capture_patch_disabled"
           - ruby_version: "head"
             rails_version: "main"
-            mode: "capture_patch_enabled"
     env:
       BUNDLE_GEMFILE: gemfiles/rails_${{ matrix.rails_version }}.gemfile
     steps:
@@ -76,7 +54,6 @@ jobs:
         RAISE_ON_WARNING: 1
         RAILS_VERSION: ${{ matrix.rails_version }}
         RUBY_VERSION: ${{ matrix.ruby_version }}
-        CAPTURE_PATCH_ENABLED: ${{ matrix.mode == 'capture_patch_enabled' && 'true' || 'false' }}
     - name: Upload coverage results
       uses: actions/upload-artifact@v4.4.0
       if: always()
@@ -114,7 +91,7 @@ jobs:
         bundle && bundle exec rake
       env:
         VIEW_COMPONENT_PATH: ../view_component
-        RAILS_VERSION: '7.1.1'
+        RAILS_VERSION: '7.1.5'
         PARALLEL_WORKERS: '1'
   coverage:
     needs: test

docs/CHANGELOG.md

@@ -10,6 +10,10 @@ nav_order: 6
 
 ## main
 
+* BREAKING: Remove dependency on `ActionView::Base`, eliminating the need for capture compatibility patch.
+
+    *Cameron Dutro*
+
 ## 4.0.0.alpha2
 
 * Add `#current_template` accessor and `Template#path` for diagnostic usage.

docs/api.md

@@ -142,13 +142,6 @@ so helpers, etc work as expected.
 
 ## Configuration
 
-### `.capture_compatibility_patch_enabled`
-
-Enables the experimental capture compatibility patch that makes ViewComponent
-compatible with forms, capture, and other built-ins.
-previews.
-Defaults to `false`.
-
 ### `.component_parent_class`
 
 The parent class from which generated components will inherit.

docs/known_issues.md

@@ -27,46 +27,6 @@ en:
 
 It would be lovely if we could support rendering ViewComponents in Jekyll, as it would enable the reuse of ViewComponents across static and dynamic (Rails-based) sites.
 
-## Issues resolved by the optional capture compatibility patch
-
-If you're experiencing issues with duplicated content or malformed HTML output (such as using `concat` in a helper), the capture compatibility patch may resolve these.
-
-[Set `config.view_component.capture_compatibility_patch_enabled` to `true`](https://viewcomponent.org/api.html#capture_compatibility_patch_enabled) to resolve these issues.
-
-These issues arise because the related features/methods keep a reference to the
-primary `ActionView::Base` instance, which has its own `@output_buffer`. When
-`#capture` is called on the original `ActionView::Base` instance while
-evaluating a block from a ViewComponent, the `@output_buffer` is overridden in
-the `ActionView::Base` instance, and *not* the component. This results in a
-double render due to `#capture` implementation details.
-
-To resolve the issue, we override `#capture` so that we can delegate the
-`capture` logic to the ViewComponent that created the block.
-
-### turbo_frame_tag double rendering or scrambled HTML structure
-
-When using `turbo_frame_tag` inside a ViewComponent, the template may be rendered twice. See [https://github.com/github/view_component/issues/1099](https://github.com/github/view_component/issues/1099).
-
-As a workaround, use `tag.turbo_frame` instead of `turbo_frame_tag`.
-
-Note: For the same functionality as `turbo_frame_tag(my_model)`, use `tag.turbo_frame(id: dom_id(my_model))`.
-
-### Compatibility with Rails form helpers
-
-ViewComponent [isn't compatible](https://github.com/viewcomponent/view_component/issues/241) with `form_for` helpers by default.
-
-Passing a form object (often `f`) to a ViewComponent works for simple cases like `f.text_field :name`. Content may be ill-ordered or duplicated in complex cases, such as passing blocks to form helpers or when nesting components.
-
-Some workarounds include:
-
-- Experimental: Enable the capture compatibility patch with `config.view_component.capture_compatibility_patch_enabled = true`.
-- Render an entire form within a single ViewComponent.
-- Render a [partial](https://guides.rubyonrails.org/layouts_and_rendering.html#using-partials) within the ViewComponent which includes the form.
-- Use a [custom `FormBuilder`](https://guides.rubyonrails.org/form_helpers.html#customizing-form-builders) to create reusable form components:
-  - Using FormBuilder with [Action View helpers](https://api.rubyonrails.org/classes/ActionView/Helpers/FormBuilder.html).
-  - Using a FormBuilder overriding all field helpers to render a ViewComponent so each field can be customized individually (for example, [view_component-form](https://github.com/pantographe/view_component-form)).
-  - Using a lightweight re-implementation of ViewComponent. For example, [Primer ViewComponents](https://github.com/primer/view_components) implemented [`ActsAsComponent`](https://github.com/primer/view_components/blob/main/lib/primer/forms/acts_as_component.rb) which is used in the context of `FormBuilder`.
-
 ## Forms don't use the default `FormBuilder`
 
 Calls to form helpers such as `form_with` in ViewComponents [don't use the default form builder](https://github.com/viewcomponent/view_component/pull/1090#issue-753331927). This is by design, as it allows global state to change the rendered output of a component. Instead, consider passing a form builder into form helpers via the `builder` argument:

lib/view_component/base.rb

@@ -18,8 +18,21 @@
 require "view_component/with_content_helper"
 require "view_component/use_helpers"
 
+module ActionView
+  class OutputBuffer
+    def with_buffer(buf = nil)
+      new_buffer = buf || +""
+      old_buffer, @raw_buffer = @raw_buffer, new_buffer
+      yield
+      new_buffer
+    ensure
+      @raw_buffer = old_buffer
+    end
+  end
+end
+
 module ViewComponent
-  class Base < ActionView::Base
+  class Base
     class << self
       delegate(*ViewComponent::Config.defaults.keys, to: :config)
 
@@ -35,6 +48,10 @@ def config
       end
     end
 
+    include ActionView::Helpers
+    include ERB::Escape
+    include ActiveSupport::CoreExt::ERBUtil
+
     include ViewComponent::InlineTemplate
     include ViewComponent::UseHelpers
     include ViewComponent::Slotable
@@ -45,6 +62,9 @@ def config
     # For CSRF authenticity tokens in forms
     delegate :form_authenticity_token, :protect_against_forgery?, :config, to: :helpers
 
+    # HTML construction methods
+    delegate :output_buffer, :lookup_context, :view_renderer, :view_flow, to: :helpers
+
     # For Content Security Policy nonces
     delegate :content_security_policy_nonce, to: :helpers
 
@@ -61,7 +81,7 @@ def config
     # @param view_context [ActionView::Base] The original view context.
     # @return [void]
     def set_original_view_context(view_context)
-      self.__vc_original_view_context = view_context
+      # noop
     end
 
     using RequestDetails
@@ -80,7 +100,7 @@ def render_in(view_context, &block)
       @view_context = view_context
       self.__vc_original_view_context ||= view_context
 
-      @output_buffer = ActionView::OutputBuffer.new
+      @output_buffer = view_context.output_buffer
 
       @lookup_context ||= view_context.lookup_context
 
@@ -107,14 +127,20 @@ def render_in(view_context, &block)
       before_render
 
       if render?
-        rendered_template = render_template_for(@__vc_requested_details).to_s
+        value = nil
+
+        @output_buffer.with_buffer do
+          rendered_template = render_template_for(@__vc_requested_details).to_s
 
-        # Avoid allocating new string when output_preamble and output_postamble are blank
-        if output_preamble.blank? && output_postamble.blank?
-          rendered_template
-        else
-          safe_output_preamble + rendered_template + safe_output_postamble
+          # Avoid allocating new string when output_preamble and output_postamble are blank
+          value = if output_preamble.blank? && output_postamble.blank?
+            rendered_template
+          else
+            safe_output_preamble + rendered_template + safe_output_postamble
+          end
         end
+
+        value
       else
         ""
       end
@@ -206,7 +232,7 @@ def initialize(*)
     def render(options = {}, args = {}, &block)
       if options.respond_to?(:set_original_view_context)
         options.set_original_view_context(self.__vc_original_view_context)
-        super
+        @view_context.render(options, args, &block)
       else
         __vc_original_view_context.render(options, args, &block)
       end

lib/view_component/capture_compatibility.rb

@@ -9,15 +9,8 @@ class Collection
 
     delegate :size, to: :@collection
 
-    attr_accessor :__vc_original_view_context
-
-    def set_original_view_context(view_context)
-      self.__vc_original_view_context = view_context
-    end
-
     def render_in(view_context, &block)
       components.map do |component|
-        component.set_original_view_context(__vc_original_view_context)
         component.render_in(view_context, &block)
       end.join(rendered_spacer(view_context)).html_safe
     end
@@ -67,7 +60,6 @@ def component_options(item, iterator)
 
     def rendered_spacer(view_context)
       if @spacer_component
-        @spacer_component.set_original_view_context(__vc_original_view_context)
         @spacer_component.render_in(view_context)
       else
         ""

lib/view_component/collection.rb

@@ -21,8 +21,7 @@ def defaults
           show_previews: Rails.env.development? || Rails.env.test?,
           preview_paths: default_preview_paths,
           test_controller: "ApplicationController",
-          default_preview_layout: nil,
-          capture_compatibility_patch_enabled: false
+          default_preview_layout: nil
         })
       end
 
@@ -145,13 +144,6 @@ def defaults
       # previews.
       # Defaults to `nil`. If this is falsy, `"component_preview"` is used.
 
-      # @!attribute capture_compatibility_patch_enabled
-      # @return [Boolean]
-      # Enables the experimental capture compatibility patch that makes ViewComponent
-      # compatible with forms, capture, and other built-ins.
-      # previews.
-      # Defaults to `false`.
-
       def default_preview_paths
         (default_rails_preview_paths + default_rails_engines_preview_paths).uniq
       end

lib/view_component/config.rb

@@ -51,12 +51,6 @@ class Engine < Rails::Engine # :nodoc:
       end
     end
 
-    initializer "view_component.enable_capture_patch" do |app|
-      ActiveSupport.on_load(:view_component) do
-        ActionView::Base.include(ViewComponent::CaptureCompatibility) if app.config.view_component.capture_compatibility_patch_enabled
-      end
-    end
-
     initializer "view_component.set_autoload_paths" do |app|
       options = app.config.view_component
 
@@ -66,6 +60,39 @@ class Engine < Rails::Engine # :nodoc:
       end
     end
 
+    initializer "view_component.propshaft_support" do |_app|
+      ActiveSupport.on_load(:view_component) do
+        if defined?(Propshaft)
+          include Propshaft::Helper
+        end
+      end
+    end
+
+    config.after_initialize do |app|
+      ActiveSupport.on_load(:view_component) do
+        if defined?(Sprockets::Rails)
+          include Sprockets::Rails::Helper
+
+          # Copy relevant config to VC context
+          # See: https://github.com/rails/sprockets-rails/blob/266ec49f3c7c96018dd75f9dc4f9b62fe3f7eecf/lib/sprockets/railtie.rb#L245
+          self.debug_assets = app.config.assets.debug
+          self.digest_assets = app.config.assets.digest
+          self.assets_prefix = app.config.assets.prefix
+          self.assets_precompile = app.config.assets.precompile
+
+          self.assets_environment = app.assets
+          self.assets_manifest = app.assets_manifest
+
+          self.resolve_assets_with = app.config.assets.resolve_with
+
+          self.check_precompiled_asset = app.config.assets.check_precompiled_asset
+          self.unknown_asset_fallback = app.config.assets.unknown_asset_fallback
+          # Expose the app precompiled asset check to the view
+          self.precompiled_asset_checker = ->(logical_path) { app.asset_precompiled? logical_path }
+        end
+      end
+    end
+
     initializer "view_component.eager_load_actions" do
       ActiveSupport.on_load(:after_initialize) do
         ViewComponent::Base.descendants.each(&:__vc_compile) if Rails.application.config.eager_load

lib/view_component/engine.rb

@@ -58,15 +58,7 @@ def to_s
           if defined?(@__vc_content_block)
             # render_in is faster than `parent.render`
             @__vc_component_instance.render_in(view_context) do |*args|
-              return @__vc_content_block.call(*args) if @__vc_content_block&.source_location.nil?
-
-              block_context = @__vc_content_block.binding.receiver
-
-              if block_context.class < ActionView::Base
-                block_context.capture(*args, &@__vc_content_block)
-              else
-                @__vc_content_block.call(*args)
-              end
+              @__vc_content_block.call(*args)
             end
           else
             @__vc_component_instance.render_in(view_context)