Use Blacklight.logger instead of hard-coding Rails.logger

lib/blacklight.rb

@@ -145,7 +145,13 @@ def self.solr_yml
   end
 
   def self.logger
-    ::Rails.logger
+    @logger ||= begin
+      ::Rails.logger if defined? Rails and Rails.respond_to? :logger
+    end
+  end
+
+  def self.logger= logger
+    @logger = logger
   end
 
   #############  

lib/blacklight/abstract_repository.rb

@@ -23,7 +23,7 @@ def connection_config
       end
 
       def logger
-        @logger ||= Rails.logger if defined? Rails
+        @logger ||= Blacklight.logger
       end
   end
 end

lib/blacklight/catalog/search_context.rb

@@ -102,7 +102,7 @@ def setup_next_and_previous_documents
       @next_document = documents.last
     end
   rescue Blacklight::Exceptions::InvalidRequest => e
-    Rails.logger.warn "Unable to setup next and previous documents: #{e}"
+    logger.warn "Unable to setup next and previous documents: #{e}"
   end
 
 end

lib/blacklight/solr_repository.rb

@@ -45,8 +45,8 @@ def send_and_receive(path, solr_params = {})
 
         solr_response = blacklight_config.response_model.new(res, solr_params, document_model: blacklight_config.document_model)
 
-        Rails.logger.debug("Solr query: #{solr_params.inspect}")
-        Rails.logger.debug("Solr response: #{solr_response.inspect}") if defined?(::BLACKLIGHT_VERBOSE_LOGGING) and ::BLACKLIGHT_VERBOSE_LOGGING
+        Blacklight.logger.debug("Solr query: #{solr_params.inspect}")
+        Blacklight.logger.debug("Solr response: #{solr_response.inspect}") if defined?(::BLACKLIGHT_VERBOSE_LOGGING) and ::BLACKLIGHT_VERBOSE_LOGGING
         solr_response
       end
     rescue Errno::ECONNREFUSED => e