Allow custom Audit classes

README.md

@@ -163,7 +163,7 @@ Audited.current_user_method = :authenticated_user
 Outside of a request, Audited can still record the user with the `as_user` method:
 
 ```ruby
-Audited::Audit.as_user(User.find(1)) do
+Audited.audit_class.as_user(User.find(1)) do
   post.update_attribute!(title: "Hello, world!")
 end
 post.audits.last.user # => #<User id: 1>
@@ -255,6 +255,26 @@ To disable auditing on an entire model:
 User.auditing_enabled = false
 ```
 
+### Custom `Audit` model
+
+If you want to extend or modify the audit model, create a new class that
+inherits from `Audited::Audit`:
+```ruby
+class CustomAudit < Audited::Audit
+  def some_custom_behavior
+    "Hiya!"
+  end
+end
+```
+Then set it in an initializer:
+```ruby
+# config/initializers/audited.rb
+
+Audited.config do |config|
+  config.audit_class = CustomAudit
+end
+```
+
 ## Gotchas
 
 ### Using attr_protected with Rails 4.x

lib/audited.rb

@@ -2,17 +2,19 @@
 
 module Audited
   class << self
-    attr_accessor :ignored_attributes, :current_user_method
+    attr_accessor :ignored_attributes, :current_user_method, :audit_class
 
-    # Deprecate audit_class accessors in preperation of their removal
     def audit_class
-      Audited::Audit
+      @audit_class || Audit
     end
-    deprecate audit_class: "Audited.audit_class is now always Audited::Audit. This method will be removed."
 
     def store
       Thread.current[:audited_store] ||= {}
     end
+
+    def config
+      yield(self)
+    end
   end
 
   @ignored_attributes = %w(lock_version created_at updated_at created_on updated_on)

lib/audited/audit.rb

@@ -16,15 +16,15 @@ module Audited
   class YAMLIfTextColumnType
     class << self
       def load(obj)
-        if Audited::Audit.columns_hash["audited_changes"].sql_type == "text"
+        if Audited.audit_class.columns_hash["audited_changes"].sql_type == "text"
           ActiveRecord::Coders::YAMLColumn.new(Object).load(obj)
         else
           obj
         end
       end
 
       def dump(obj)
-        if Audited::Audit.columns_hash["audited_changes"].sql_type == "text"
+        if Audited.audit_class.columns_hash["audited_changes"].sql_type == "text"
           ActiveRecord::Coders::YAMLColumn.new(Object).dump(obj)
         else
           obj

lib/audited/auditor.rb

@@ -51,8 +51,8 @@ def audited(options = {})
 
         attr_accessor :audit_comment
 
-        has_many :audits, -> { order(version: :asc) }, as: :auditable, class_name: Audit.name
-        Audit.audited_class_names << to_s
+        has_many :audits, -> { order(version: :asc) }, as: :auditable, class_name: Audited.audit_class.name
+        Audited.audit_class.audited_class_names << to_s
 
         on = Array(options[:on])
         after_create :audit_create    if on.empty? || on.include?(:create)
@@ -75,7 +75,7 @@ def audited(options = {})
       end
 
       def has_associated_audits
-        has_many :associated_audits, as: :associated, class_name: Audit.name
+        has_many :associated_audits, as: :associated, class_name: Audited.audit_class.name
       end
 
       def default_ignored_attributes
@@ -118,13 +118,13 @@ def revisions(from_version = 1)
 
       # Get a specific revision specified by the version number, or +:previous+
       def revision(version)
-        revision_with Audit.reconstruct_attributes(audits_to(version))
+        revision_with Audited.audit_class.reconstruct_attributes(audits_to(version))
       end
 
       # Find the oldest revision recorded prior to the date/time provided.
       def revision_at(date_or_time)
         audits = self.audits.up_until(date_or_time)
-        revision_with Audit.reconstruct_attributes(audits) unless audits.empty?
+        revision_with Audited.audit_class.reconstruct_attributes(audits) unless audits.empty?
       end
 
       # List of attributes that are audited.
@@ -152,7 +152,7 @@ def revision_with(attributes)
           revision.send :instance_variable_set, '@destroyed', false
           revision.send :instance_variable_set, '@_destroyed', false
           revision.send :instance_variable_set, '@marked_for_destruction', false
-          Audit.assign_revision_attributes(revision, attributes)
+          Audited.audit_class.assign_revision_attributes(revision, attributes)
 
           # Remove any association proxies so that they will be recreated
           # and reference the correct object for this revision. The only way
@@ -298,7 +298,7 @@ def enable_auditing
       # convenience wrapper around
       # @see Audit#as_user.
       def audit_as(user, &block)
-        Audit.as_user(user, &block)
+        Audited.audit_class.as_user(user, &block)
       end
 
       def auditing_enabled

lib/audited/rspec_matchers.rb

@@ -170,7 +170,7 @@ def reflection
       def association_exists?
         !reflection.nil? &&
           reflection.macro == :has_many &&
-          reflection.options[:class_name] == Audit.name
+          reflection.options[:class_name] == Audited.audit_class.name
       end
     end
   end

spec/audited/audit_spec.rb

@@ -3,6 +3,54 @@
 describe Audited::Audit do
   let(:user) { Models::ActiveRecord::User.new name: "Testing" }
 
+  describe "audit class" do
+    around(:example) do |example|
+      original_audit_class = Audited.audit_class
+
+      class CustomAudit < Audited::Audit
+        def custom_method
+          "I'm custom!"
+        end
+      end
+
+      class TempModel < ::ActiveRecord::Base
+        self.table_name = :companies
+      end
+
+      example.run
+
+      Audited.config { |config| config.audit_class = original_audit_class }
+      Audited::Audit.audited_class_names.delete("TempModel")
+      Object.send(:remove_const, :TempModel)
+      Object.send(:remove_const, :CustomAudit)
+    end
+
+    context "when a custom audit class is configured" do
+      it "should be used in place of #{described_class}" do
+        Audited.config { |config| config.audit_class = CustomAudit }
+        TempModel.audited
+
+        record = TempModel.create
+
+        audit = record.audits.first
+        expect(audit).to be_a CustomAudit
+        expect(audit.custom_method).to eq "I'm custom!"
+      end
+    end
+
+    context "when a custom audit class is not configured" do
+      it "should default to #{described_class}" do
+        TempModel.audited
+
+        record = TempModel.create
+
+        audit = record.audits.first
+        expect(audit).to be_a Audited::Audit
+        expect(audit.respond_to?(:custom_method)).to be false
+      end
+    end
+  end
+
   describe "user=" do
 
     it "should be able to set the user to a model object" do