feat(ViewHelper) add lifecycle hooks

Author: rmosolgo

lib/react/rails/component_mount.rb

@@ -1,10 +1,23 @@
 module React
   module Rails
+    # This is the default view helper implementation.
+    # It just inserts HTML into the DOM (see {#react_component}).
+    #
+    # You can extend this class or provide your own implementation
+    # by assigning it to `config.react.view_helper_implementation`.
     class ComponentMount
       include ActionView::Helpers::TagHelper
       include ActionView::Helpers::TextHelper
       attr_accessor :output_buffer
 
+      # RenderMiddleware calls these hooks
+      # You can use them in custom helper implementations
+      def setup(env)
+      end
+
+      def teardown(env)
+      end
+
       # Render a UJS-type HTML tag annotated with data attributes, which
       # are used by react_ujs to actually instantiate the React component
       # on the client.

lib/react/rails/controller_renderer.rb

@@ -5,8 +5,9 @@ class React::Rails::ControllerRenderer
 
   attr_accessor :output_buffer
 
-  def self.call(*args, &block)
-    new.call(*args, &block)
+  attr_reader :request
+  def initialize(options={})
+    @request = options[:request]
   end
 
   def call(name, options, &block)

lib/react/rails/railtie.rb

@@ -38,7 +38,8 @@ class Railtie < ::Rails::Railtie
 
       initializer "react_rails.add_component_renderer", group: :all do |app|
         ActionController::Renderers.add :component do |component_name, options|
-          html = ::React::Rails::ControllerRenderer.call(component_name, options)
+          renderer = ::React::Rails::ControllerRenderer.new(request: request)
+          html = renderer.call(component_name, options)
           render_options = options.merge(inline: html)
           render(render_options)
         end

lib/react/rails/render_middleware.rb

@@ -8,8 +8,11 @@ def initialize(app)
 
       def call(env)
         new_helper = React::Rails::ViewHelper.helper_implementation_class.new
+        new_helper.setup(env)
         env[HELPER_IMPLEMENTATION_KEY] = new_helper
-        @app.call(env)
+        response = @app.call(env)
+        new_helper.teardown(env)
+        response
       end
     end
   end

lib/react/rails/view_helper.rb

@@ -2,7 +2,10 @@ module React
   module Rails
     module ViewHelper
       # This class will be used for inserting tags into HTML.
-      # It should implement react_component(name, props, options &block)
+      # It should implement:
+      #   - #setup(env)
+      #   - #teardown(env)
+      #   - #react_component(name, props, options &block)
       # The default is {React::Rails::ComponentMount}
       mattr_accessor :helper_implementation_class
 

test/react/rails/render_middleware_test.rb

@@ -3,13 +3,21 @@
 # This helper implementation just counts the number of
 # calls to `react_component`
 class DummyHelperImplementation
-  attr_reader :counter
+  attr_reader :events
   def initialize
-    @counter = 0
+    @events = []
+  end
+
+  def setup(env)
+    @events << :setup
+  end
+
+  def teardown(env)
+    @events << :teardown
   end
 
   def react_component(*args)
-    @counter += 1
+    @events << :react_component
   end
 end
 
@@ -29,7 +37,13 @@ def teardown
     get '/pages/1'
     helper_obj = request.env[impl_key]
     assert(helper_obj.is_a?(DummyHelperImplementation), "It uses the view helper implementation class")
-    assert_equal(1, helper_obj.counter, "It uses that object during rendering")
+  end
+
+  test "it calls setup and teardown methods" do
+    get '/pages/1'
+    helper_obj = request.env[impl_key]
+    lifecycle_steps = [:setup, :react_component, :teardown]
+    assert_equal(lifecycle_steps, helper_obj.events)
   end
 
   test "there's a new helper object for every request" do