From c8f7e94eec25dbc981af77bbb5e462867c402d07 Mon Sep 17 00:00:00 2001
From: Amos King <amos.l.king@gmail.com>
Date: Tue, 29 Jun 2010 23:42:05 -0500
Subject: [PATCH] adds support for try as a proxy object [#5013 state:resolved]

---
 .../lib/active_support/core_ext/object/try.rb      |   31 ++++++----------
 .../test/core_ext/object_and_class_ext_test.rb     |   36 +++++++++++++++++---
 2 files changed, 43 insertions(+), 24 deletions(-)

diff --git a/activesupport/lib/active_support/core_ext/object/try.rb b/activesupport/lib/active_support/core_ext/object/try.rb
index a1c63a0..f574195 100644
--- a/activesupport/lib/active_support/core_ext/object/try.rb
+++ b/activesupport/lib/active_support/core_ext/object/try.rb
@@ -1,9 +1,6 @@
 class Object
-  # Invokes the method identified by the symbol +method+, passing it any arguments
-  # and/or the block specified, just like the regular Ruby <tt>Object#send</tt> does.
-  #
-  # *Unlike* that method however, a +NoMethodError+ exception will *not* be raised
-  # and +nil+ will be returned instead, if the receiving object is a +nil+ object or NilClass.
+  # Tries to send the method only if object responds to it. Return +nil+ otherwise.
+  # It will also forward any arguments and/or block like Object#send does.
   #
   # ==== Examples
   #
@@ -13,24 +10,20 @@ class Object
   #   @person ? @person.name : nil
   #
   # With try
-  #   @person.try(:name)
+  #   @person.try.name
   #
-  # +try+ also accepts arguments and/or a block, for the method it is trying
-  #   Person.try(:find, 1)
-  #   @people.try(:collect) {|p| p.name}
-  #--
-  # This method definition below is for rdoc purposes only. The alias_method call
-  # below overrides it as an optimization since +try+ behaves like +Object#send+,
-  # unless called on +NilClass+.
-  def try(method, *args, &block)
-    send(method, *args, &block)
+  # Try also accepts arguments/blocks for the method it is trying
+  #   Person.try.find(1)
+  #   @people.try.collect {|p| p.name}
+  def try(method = nil, *args, &block)
+    method ? self.send(method, *args, &block) : self
   end
-  remove_method :try
-  alias_method :try, :__send__
 end
 
-class NilClass #:nodoc:
+class NilClass
+  Try = Class.new(BlankSlate) { def method_missing(*) nil; end }
+  
   def try(*args)
-    nil
+    args.empty? ? Try.new : nil
   end
 end
diff --git a/activesupport/test/core_ext/object_and_class_ext_test.rb b/activesupport/test/core_ext/object_and_class_ext_test.rb
index 5e03389..3a90b07 100644
--- a/activesupport/test/core_ext/object_and_class_ext_test.rb
+++ b/activesupport/test/core_ext/object_and_class_ext_test.rb
@@ -189,29 +189,55 @@ class ObjectTryTest < Test::Unit::TestCase
   end
 
   def test_nonexisting_method
+    assert !@string.respond_to?(:undefined_method)
+    assert_raise(NoMethodError) { @string.try.undefined_method }
+  end
+  
+  def test_valid_method
+    assert_equal 5, @string.try.size
+  end
+
+  def test_argument_forwarding
+    assert_equal 'Hey', @string.try.sub('llo', 'y')
+  end
+
+  def test_block_forwarding
+    assert_equal 'Hey', @string.try.sub('llo') { |match| 'y' }
+  end
+
+  def test_nil_to_type
+    assert_nil nil.try.to_s
+    assert_nil nil.try.to_i
+  end
+
+  def test_false_try
+    assert_equal 'false', false.try.to_s
+  end
+  
+  def test_nonexisting_method_depricated
     method = :undefined_method
     assert !@string.respond_to?(method)
     assert_raise(NoMethodError) { @string.try(method) }
   end
   
-  def test_valid_method
+  def test_valid_method_depricated
     assert_equal 5, @string.try(:size)
   end
 
-  def test_argument_forwarding
+  def test_argument_forwarding_depricated
     assert_equal 'Hey', @string.try(:sub, 'llo', 'y')
   end
 
-  def test_block_forwarding
+  def test_block_forwarding_depricated
     assert_equal 'Hey', @string.try(:sub, 'llo') { |match| 'y' }
   end
 
-  def test_nil_to_type
+  def test_nil_to_type_depricated
     assert_nil nil.try(:to_s)
     assert_nil nil.try(:to_i)
   end
 
-  def test_false_try
+  def test_false_try_depricated
     assert_equal 'false', false.try(:to_s)
   end
 end
-- 
1.6.2.1.389.geed1