per-instance json serialization methods/excludes

refs CNVS-7597

allows streamlining some previously overridden to_json methods

test-plan: N/A

Change-Id: I401500d4fef301c8cdae455d4f71a130e2764108
Reviewed-on: https://gerrit.instructure.com/23645
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Jacob Fugal <jacob@instructure.com>
QA-Review: Jacob Fugal <jacob@instructure.com>

app/models/rubric_assessment.rb

@@ -171,6 +171,10 @@ class RubricAssessment < ActiveRecord::Base
   def methods_for_serialization(*methods)
     @serialization_methods = methods
   end
+
+  def serialization_methods
+    @serialization_methods || []
+  end
   
   def assessor_name
     self.assessor.name rescue t('unknown_user', "Unknown User")

app/models/submission.rb

@@ -1004,22 +1004,21 @@ class Submission < ActiveRecord::Base
     end
   end
 
-  # This little chunk makes it so that to_json will force it to always include the method :attachments
-  # it is especially needed in the extended gradebook so that when we grab all of the versions through simply_versioned
-  # that each of those versions include :attachments
-  alias_method :ar_to_json, :to_json
-  def to_json(options = {}, &block)
-    if simply_versioned_version_model
-      options[:methods] ||= []
-      options[:methods] = Array(options[:methods])
-      options[:methods] << :versioned_attachments
-      options[:methods].uniq!
-    end
-    self.ar_to_json(options, &block)
-    # default_options = { :methods => [ :attachments ]}
-    # options[:methods] = [options[:methods]] if options[:methods] && !options[:methods].is_a?(Array)
-    # default_options[:methods] += options[:methods] if options[:methods]
-    # self.ar_to_json(options.merge(default_options), &block)
+  # include the versioned_attachments in as_json if this was loaded from a
+  # specific version
+  def serialization_methods
+    !@without_versioned_attachments && simply_versioned_version_model ?
+      [:versioned_attachments] :
+      []
+  end
+
+  # mechanism to turn off the above behavior for the duration of a
+  # block
+  def without_versioned_attachments
+    original, @without_versioned_attachments = @without_versioned_attachments, true
+    yield
+  ensure
+    @exclude_versioned_attachments = original
   end
 
   def self.json_serialization_full_parameters(additional_parameters={})

app/models/submission_comment.rb

@@ -208,13 +208,8 @@ class SubmissionComment < ActiveRecord::Base
     !hidden? && submission.possible_participants_ids.include?(author_id)
   end
 
-  alias_method :ar_to_json, :to_json
-  def to_json(options = {}, &block)
-    if self.context.root_account.service_enabled?(:avatars)
-      options[:methods] ||= []
-      options[:methods] << :avatar_path
-    end
-    self.ar_to_json(options, &block)
+  def serialization_methods
+    context.root_account.service_enabled?(:avatars) ? [:avatar_path] : []
   end
 
   scope :visible, where(:hidden => false)

config/initializers/active_record.rb

@@ -238,12 +238,13 @@ class ActiveRecord::Base
     except = options.delete(:except) || []
     except = Array(except)
     except.concat(self.class.serialization_excludes) if self.class.respond_to?(:serialization_excludes)
-    except.concat(@serialization_excludes) if @serialization_excludes
+    except.concat(self.serialization_excludes) if self.respond_to?(:serialization_excludes)
     except.uniq!
+
     methods = options.delete(:methods) || []
     methods = Array(methods)
     methods.concat(self.class.serialization_methods) if self.class.respond_to?(:serialization_methods)
-    methods.concat(@serialization_methods) if @serialization_methods
+    methods.concat(self.serialization_methods) if self.respond_to?(:serialization_methods)
     methods.uniq!
 
     options[:except] = except unless except.empty?

lib/api/v1/gradebook_history.rb

@@ -30,7 +30,10 @@ module Api::V1
       student = opts[:student] || submission.user
       current_grader = submission.grader || default_grader
 
-      json = submission_attempt_json(version.model, assignment, api_context.user, api_context.session, nil, course).with_indifferent_access
+      model = version.model
+      json = model.without_versioned_attachments do
+        submission_attempt_json(model, assignment, api_context.user, api_context.session, nil, course).with_indifferent_access
+      end
       grader = (json[:grader_id] && json[:grader_id] > 0 && user_cache[json[:grader_id]]) || default_grader
 
       json = json.merge(

lib/api/v1/submission.rb

@@ -31,7 +31,9 @@ module Api::V1::Submission
     if includes.include?("submission_history")
       hash['submission_history'] = []
       submission.submission_history.each_with_index do |ver, idx|
-        hash['submission_history'] << submission_attempt_json(ver, assignment, user, session, idx, context)
+        ver.without_versioned_attachments do
+          hash['submission_history'] << submission_attempt_json(ver, assignment, user, session, idx, context)
+        end
       end
     end