Don't stream CSV in development

This enables any exceptions to bubble up, instead of waiting until the
request times out before sending back any data. This also lets you use
in-browser debuggers, like better_errors.

Author: seanlinsley

lib/active_admin/application.rb

@@ -125,6 +125,9 @@ def initialize
                                       :email,
                                       :to_s ]
 
+    # To make debugging easier, by default don't stream in development
+    setting :disable_streaming_in, ['development']
+
     # == Deprecated Settings
 
     def allow_comments=(*)

lib/active_admin/csv_builder.rb

@@ -39,29 +39,31 @@ def column(name, options={}, &block)
       @columns << Column.new(name, @resource, column_transitive_options.merge(options), block)
     end
 
-    def build(controller, receiver)
+    def build(controller, csv)
       @collection = controller.send(:find_collection, except: :pagination)
       options = ActiveAdmin.application.csv_options.merge self.options
       columns = exec_columns controller.view_context
 
       if byte_order_mark = options.delete(:byte_order_mark)
-        receiver << byte_order_mark
+        csv << byte_order_mark
       end
 
       if options.delete(:column_names) { true }
-        receiver << CSV.generate_line(
+        csv << CSV.generate_line(
           columns.map { |c| encode c.name, options },
           options.except(:encoding_options))
       end
 
       (1..paginated_collection.total_pages).each do |page_no|
         paginated_collection(page_no).each do |resource|
           resource = controller.send :apply_decorator, resource
-          receiver << CSV.generate_line(
+          csv << CSV.generate_line(
             build_row(resource, columns, options),
             options.except(:encoding_options))
         end
       end
+
+      csv
     end
 
     def exec_columns(view_context = nil)

lib/active_admin/resource_controller/streaming.rb

@@ -20,7 +20,12 @@ def index
       def stream_resource(&block)
         headers['X-Accel-Buffering'] = 'no'
         headers['Cache-Control'] = 'no-cache'
-        self.response_body = Enumerator.new &block
+
+        if ActiveAdmin.application.disable_streaming_in.include? Rails.env
+          self.response_body = block['']
+        else
+          self.response_body = Enumerator.new &block
+        end
       end
 
       def csv_filename