Added before_validation callback

lib/active_presenter/base.rb

@@ -3,7 +3,7 @@ module ActivePresenter
   #
   class Base
     include ActiveSupport::Callbacks
-    define_callbacks :before_save, :after_save
+    define_callbacks :before_validation, :before_save, :after_save
 
     class_inheritable_accessor :presented
     self.presented = {}
@@ -87,13 +87,15 @@ def errors
     # Returns boolean based on the validity of the presentables by calling valid? on each of them.
     #
     def valid?
-      presented.keys.each do |type|
-        presented_inst = send(type)
-
-        merge_errors(presented_inst, type) unless presented_inst.valid?
+      if run_callbacks_with_halt(:before_validation)
+        presented.keys.each do |type|
+          presented_inst = send(type)
+
+          merge_errors(presented_inst, type) unless presented_inst.valid?
+        end
+
+        errors.empty?
       end
-
-      errors.empty?
     end
 
     # Save all of the presentables, wrapped in a transaction.
@@ -120,10 +122,10 @@ def save
     # Returns true on success, will raise otherwise.
     # 
     def save!
+      raise ActiveRecord::RecordInvalid.new(self) unless valid?
       raise ActiveRecord::RecordNotSaved unless run_callbacks_with_halt(:before_save)
 
       ActiveRecord::Base.transaction do
-        valid? # collect errors before potential exception raise
         presented_instances.each { |i| i.save! }
       end
 

test/base_test.rb

@@ -83,18 +83,18 @@
   end
 
   expect ActiveRecord::Base.to.receive(:transaction) do
-    s = SignupPresenter.new
+    s = SignupPresenter.new(:user_login => "da", :user_password => "seekrit")
     s.save!
   end
 
   expect User.any_instance.to.receive(:save!) do
-    s = SignupPresenter.new
+    s = SignupPresenter.new(:user_login => "da", :user_password => "seekrit")
     s.save!
   end
 
   expect Account.any_instance.to.receive(:save!) do
     User.any_instance.stubs(:save!)
-    s = SignupPresenter.new
+    s = SignupPresenter.new(:user_login => "da", :user_password => "seekrit")
     s.save!
   end
 
@@ -177,4 +177,10 @@
 
   expect SamePrefixPresenter.new.to.be.respond_to?(:account_title)
   expect SamePrefixPresenter.new.to.be.respond_to?(:account_info_info)
+
+  expect [:before_validation, :before_save, :after_save] do
+    returning(CallbackOrderingPresenter.new) do |presenter|
+      presenter.save!
+    end.steps
+  end
 end

test/test_helper.rb

@@ -68,6 +68,33 @@ class SamePrefixPresenter < ActivePresenter::Base
   presents :account, :account_info
 end
 
+class CallbackOrderingPresenter < ActivePresenter::Base
+  presents :account
+
+  before_validation :do_before_validation
+  before_save :do_before_save
+  after_save :do_after_save
+
+  attr_reader :steps
+
+  def initialize(params={})
+    super
+    @steps = []
+  end
+
+  def do_before_validation
+    @steps << :before_validation
+  end
+
+  def do_before_save
+    @steps << :before_save
+  end
+
+  def do_after_save
+    @steps << :after_save
+  end
+end
+
 def hash_for_user(opts = {})
   {:login => 'jane', :password => 'seekrit' }.merge(opts)
 end