Merge pull request #2112 from tf/additional-headers

Allow registering additional headers for published entries

app/controllers/pageflow/entries_controller.rb

@@ -84,22 +84,29 @@ def delegate_to_entry_type_frontend_app!(entry)
       EntriesControllerEnvHelper.add_entry_info_to_env(request.env, entry: entry, mode: :published)
 
       delegate_to_rack_app!(entry.entry_type.frontend_app) do |_status, headers, _body|
+        config = Pageflow.config_for(entry)
+
         allow_iframe_for_embed(headers)
-        apply_cache_control(entry, headers)
+        apply_additional_headers(entry, config, headers)
+        apply_cache_control(entry, config, headers)
       end
     end
 
     def allow_iframe_for_embed(headers)
       headers.except!('X-Frame-Options') if params[:embed]
     end
 
-    def apply_cache_control(entry, headers)
-      config = Pageflow.config_for(entry)
-
+    def apply_cache_control(entry, config, headers)
       return if config.public_entry_cache_control_header.blank?
       return if entry.password_protected?
 
       headers['Cache-Control'] = config.public_entry_cache_control_header
     end
+
+    def apply_additional_headers(entry, config, headers)
+      headers.merge!(
+        config.additional_public_entry_headers.for(entry, request)
+      )
+    end
   end
 end

entry_types/scrolled/lib/pageflow_scrolled/configuration.rb

@@ -10,7 +10,7 @@ class Configuration
     # @example
     #
     #     config.additional_frontend_packs.register(
-    #       pageflow-scrolled/contentElements/some-pack',
+    #       'pageflow-scrolled/contentElements/some-pack',
     #       content_element_type_names: ['someType']
     #     )
     #
@@ -23,7 +23,7 @@ class Configuration
     # @example
     #
     #     config.additional_editor_packs.register(
-    #       pageflow-scrolled/contentElements/some-pack'
+    #       'pageflow-scrolled/contentElements/some-pack'
     #     )
     #
     # @return [AdditionalPacks]
@@ -36,8 +36,8 @@ class Configuration
     # @example
     #
     #     config.additional_frontend_seed_data.register(
-    #       pageflow-scrolled/contentElements/some-pack',
-    #       ->(entry, request) { {some: 'data'}}
+    #       'someData',
+    #       ->(entry:, request:, **) { {some: 'data'}}
     #     )
     #
     # @return [AdditionalSeedData]

lib/pageflow/additional_headers.rb

@@ -0,0 +1,27 @@
+module Pageflow
+  # Register additional response headers for published entries.
+  class AdditionalHeaders
+    # @api private
+    def initialize
+      @headers = []
+    end
+
+    # Either a hash of name values pair or a callable taking a
+    # {PublishedEntry} record and an {ActionDispatch::Request} object
+    # and returns a hash.
+    def register(headers)
+      @headers << headers
+    end
+
+    # @api private
+    def for(entry, request)
+      @headers.map { |headers|
+        if headers.respond_to?(:call)
+          headers.call(entry, request)
+        else
+          headers
+        end
+      }.reduce({}, :merge)
+    end
+  end
+end

lib/pageflow/configuration.rb

@@ -187,8 +187,8 @@ class Configuration
     attr_accessor :public_entry_request_scope
 
     # Either a lambda or an object with a `call` method taking an
-    # {Entry} record and an {ActionDispatch::Request} object and
-    # returning `nil` or a path to redirect to. Can be used in
+    # {PublishedEntry} record and an {ActionDispatch::Request} object
+    # and returning `nil` or a path to redirect to. Can be used in
     # conjuction with {PrimaryDomainEntryRedirect} to make sure
     # entries are accessed via their account's configured cname.
     #
@@ -208,6 +208,24 @@ class Configuration
     # @return [String]
     attr_accessor :public_entry_cache_control_header
 
+    # Provide additional response headers for published entries.
+    #
+    # @example
+    #
+    #     config.additional_public_entry_headers.register(
+    #       {'Some' => 'value'}
+    #     )
+    #
+    #     config.additional_public_entry_headers.register(
+    #       lambda do |_entry, request|
+    #         {'Some' => request.headers['Other']}
+    #       end
+    #     )
+    #
+    # @return [AdditionalHeaders]
+    # @since edge
+    attr_reader :additional_public_entry_headers
+
     # Either a lambda or an object with a `call` method taking a
     # {Site} as paramater and returing a hash of options used to
     # construct the url of a published entry.
@@ -435,6 +453,7 @@ def initialize(target_type_name = nil)
       @site_request_scope = CnameSiteRequestScope.new
       @public_entry_request_scope = lambda { |entries, request| entries }
       @public_entry_redirect = ->(_entry, _request) { nil }
+      @additional_public_entry_headers = AdditionalHeaders.new
       @public_entry_url_options = Pageflow::SitesHelper::DEFAULT_PUBLIC_ENTRY_OPTIONS
       @entry_embed_url_options = {protocol: 'https'}
 
@@ -578,6 +597,7 @@ def enable_all_features
       delegate :themes, to: :config
       delegate :widget_types, to: :config
       delegate :public_entry_cache_control_header=, to: :config
+      delegate :additional_public_entry_headers, to: :config
 
       delegate :for_entry_type, to: :config
     end

spec/pageflow/additional_headers_spec.rb

@@ -0,0 +1,32 @@
+require 'spec_helper'
+
+module Pageflow
+  describe AdditionalHeaders do
+    it 'returns empty hash by default' do
+      additional_headers = AdditionalHeaders.new
+      entry = create(:published_entry)
+
+      result = additional_headers.for(entry, request)
+
+      expect(result).to eq({})
+    end
+
+    it 'merges multiple registered hashes of headers' do
+      additional_headers = AdditionalHeaders.new
+      entry = create(:published_entry)
+
+      additional_headers.register('Some' => 'value')
+      additional_headers.register('Other' => 'header')
+      additional_headers.register(proc { {'Dynamic' => 'header'} })
+      result = additional_headers.for(entry, request)
+
+      expect(result).to eq('Some' => 'value',
+                           'Other' => 'header',
+                           'Dynamic' => 'header')
+    end
+
+    def request(uri = 'https://example.com')
+      ActionDispatch::Request.new(Rack::MockRequest.env_for(uri))
+    end
+  end
+end

spec/requests/pageflow/entries_show_request_spec.rb

@@ -395,6 +395,77 @@ module Pageflow
           expect(response.headers['Cache-Control']).to eq('public, max-age=3600')
         end
       end
+
+      describe 'with additional headers' do
+        it 'adds headers to responds' do
+          pageflow_configure do |config|
+            config.additional_public_entry_headers.register('X-Some' => 'value')
+          end
+
+          entry = create(:entry, :published,
+                         type_name: 'test')
+
+          get(short_entry_url(entry))
+
+          expect(response.status).to eq(200)
+          expect(response.headers['X-Some']).to eq('value')
+        end
+
+        it 'passes entry and request to callable' do
+          pageflow_configure do |config|
+            config.additional_public_entry_headers.register(
+              lambda do |entry, request|
+                {
+                  'X-From-Entry' => entry.type_name,
+                  'X-From-Request' => request.subdomain
+                }
+              end
+            )
+          end
+
+          entry = create(:entry, :published,
+                         type_name: 'test')
+
+          get(short_entry_url(entry), headers: {'HTTP_HOST' => 'news.example.com'})
+
+          expect(response.status).to eq(200)
+          expect(response.headers['X-From-Entry']).to eq('test')
+          expect(response.headers['X-From-Request']).to eq('news')
+        end
+
+        it 'does not use headers registered in feature flag by default' do
+          pageflow_configure do |config|
+            config.features.register('some_header') do |feature_config|
+              feature_config.additional_public_entry_headers.register('X-Some' => 'value')
+            end
+          end
+
+          entry = create(:entry, :published,
+                         type_name: 'test')
+
+          get(short_entry_url(entry))
+
+          expect(response.status).to eq(200)
+          expect(response.headers).not_to have_key('X-Some')
+        end
+
+        it 'uses headers registered in enabled feature flag' do
+          pageflow_configure do |config|
+            config.features.register('some_header') do |feature_config|
+              feature_config.additional_public_entry_headers.register('X-Some' => 'value')
+            end
+          end
+
+          entry = create(:entry, :published,
+                         type_name: 'test',
+                         with_feature: 'some_header')
+
+          get(short_entry_url(entry))
+
+          expect(response.status).to eq(200)
+          expect(response.headers['X-Some']).to eq('value')
+        end
+      end
     end
   end
 end