From b5c3c73501f54fbffcc8e62140640b2dc5acc29c Mon Sep 17 00:00:00 2001
From: Chris Beer <chris@cbeer.info>
Date: Fri, 3 Feb 2023 08:48:43 -0800
Subject: [PATCH 1/2] Move Configuration.default_values to a class attribute;
 partial backport of #2826

---
 lib/blacklight/configuration.rb | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/blacklight/configuration.rb b/lib/blacklight/configuration.rb
index e0304d8f86..cdbf8b1549 100644
--- a/lib/blacklight/configuration.rb
+++ b/lib/blacklight/configuration.rb
@@ -20,15 +20,14 @@ class Configuration < OpenStructWithHashAccess
       autoload :ShowField
     end
 
+
+    class_attribute :default_values, default: {}
+
     # Set up Blacklight::Configuration.default_values to contain the basic, required Blacklight fields
     class << self
       def property(key, default: nil)
         default_values[key] = default
       end
-
-      def default_values
-        @default_values ||= {}
-      end
     end
     # === Search request configuration
 

From 158bf778ee18b46664e071f08c349e2c417f895d Mon Sep 17 00:00:00 2001
From: Chris Beer <chris@cbeer.info>
Date: Mon, 19 Dec 2022 12:33:11 -0800
Subject: [PATCH 2/2] Backport Blacklight::Configuration.default_configuration
 block setup

---
 lib/blacklight/configuration.rb              | 25 +++++++++++++++++++-
 lib/blacklight/engine.rb                     |  4 ++++
 spec/models/blacklight/configuration_spec.rb | 22 +++++++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/lib/blacklight/configuration.rb b/lib/blacklight/configuration.rb
index cdbf8b1549..df4493194c 100644
--- a/lib/blacklight/configuration.rb
+++ b/lib/blacklight/configuration.rb
@@ -20,7 +20,6 @@ class Configuration < OpenStructWithHashAccess
       autoload :ShowField
     end
 
-
     class_attribute :default_values, default: {}
 
     # Set up Blacklight::Configuration.default_values to contain the basic, required Blacklight fields
@@ -28,7 +27,29 @@ class << self
       def property(key, default: nil)
         default_values[key] = default
       end
+
+      def default_configuration(&block)
+        @default_configurations ||= []
+
+        if block
+          @default_configurations << block
+
+          block.call if @default_configuration_initialized
+        end
+
+        @default_configurations
+      end
+
+      def initialize_default_configuration
+        @default_configurations&.map(&:call)
+        @default_configuration_initialized = true
+      end
+
+      def initialized_default_configuration?
+        @default_configuration_initialized
+      end
     end
+
     # === Search request configuration
 
     # @!attribute http_method
@@ -356,6 +377,8 @@ def default_per_page
     define_field_access :email_field, Blacklight::Configuration::DisplayField
 
     def initialize(hash = {})
+      self.class.initialize_default_configuration unless self.class.initialized_default_configuration?
+
       super(self.class.default_values.deep_dup.merge(hash))
       yield(self) if block_given?
 
diff --git a/lib/blacklight/engine.rb b/lib/blacklight/engine.rb
index 3cf0202e09..97bd1c8d5e 100644
--- a/lib/blacklight/engine.rb
+++ b/lib/blacklight/engine.rb
@@ -14,6 +14,10 @@ class Engine < Rails::Engine
       end
     end
 
+    config.after_initialize do
+      Blacklight::Configuration.initialize_default_configuration
+    end
+
     # This makes our rake tasks visible.
     rake_tasks do
       Dir.chdir(File.expand_path(File.join(File.dirname(__FILE__), '..'))) do
diff --git a/spec/models/blacklight/configuration_spec.rb b/spec/models/blacklight/configuration_spec.rb
index 19f4945cdb..7e2a93bac3 100644
--- a/spec/models/blacklight/configuration_spec.rb
+++ b/spec/models/blacklight/configuration_spec.rb
@@ -723,4 +723,26 @@
       expect { config.view.a = '123' }.to raise_error(FrozenError)
     end
   end
+
+  describe '.default_configuration' do
+    it 'adds additional default configuration properties' do
+      Blacklight::Configuration.default_configuration do
+        Blacklight::Configuration.default_values[:a] = '123'
+      end
+
+      Blacklight::Configuration.default_configuration do
+        Blacklight::Configuration.default_values[:b] = 'abc'
+      end
+
+      expect(Blacklight::Configuration.default_values[:a]).to eq '123'
+      expect(Blacklight::Configuration.default_values[:b]).to eq 'abc'
+    ensure
+      # reset the default configuration
+      Blacklight::Configuration.default_values.delete(:a)
+      Blacklight::Configuration.default_values.delete(:b)
+
+      Blacklight::Configuration.default_configuration.delete_at(1)
+      Blacklight::Configuration.default_configuration.delete_at(2)
+    end
+  end
 end