From 0da4367c173b139bfe653df9defdfb927541da45 Mon Sep 17 00:00:00 2001
From: Ryan Angilly <ryan@angilly.com>
Date: Thu, 29 Jan 2009 00:15:37 -0500
Subject: [PATCH] adding or_if_blank.rb and test

---
 .../lib/active_support/core_ext/or_if_blank.rb     |   19 +++++++++++++++++++
 activesupport/test/core_ext/or_if_blank_test.rb    |   13 +++++++++++++
 2 files changed, 32 insertions(+), 0 deletions(-)
 create mode 100644 activesupport/lib/active_support/core_ext/or_if_blank.rb
 create mode 100644 activesupport/test/core_ext/or_if_blank_test.rb

diff --git a/activesupport/lib/active_support/core_ext/or_if_blank.rb b/activesupport/lib/active_support/core_ext/or_if_blank.rb
new file mode 100644
index 0000000..0ebc311
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/or_if_blank.rb
@@ -0,0 +1,19 @@
+class Object
+  # This simplifies cases where you want to do:
+  #
+  #   self.email.blank? ? self.name : self.email
+  #
+  # you can now do:
+  # 
+  #   self.email.or_if_blank self.name
+  #
+  # It will work on any object that implements blank?
+
+  def or_if_blank(val)
+    if respond_to? :blank?
+      self.blank? ? val : self
+    else
+      self
+    end
+  end
+end
diff --git a/activesupport/test/core_ext/or_if_blank_test.rb b/activesupport/test/core_ext/or_if_blank_test.rb
new file mode 100644
index 0000000..240bc6b
--- /dev/null
+++ b/activesupport/test/core_ext/or_if_blank_test.rb
@@ -0,0 +1,13 @@
+require 'abstract_unit'
+
+class OrIfBlankTest < Test::Unit::TestCase
+  BLANK = ["", [], {}, nil, false]
+  NOT = ["a", [1,2], {:a => 2}, true, 0]
+
+  def test_or_if_blank
+    substitute = "substitute me!"
+
+    BLANK.each { |v| assert_equal v.or_if_blank(substitute), substitute }
+    NOT.each { |v| assert_equal v.or_if_blank(substitute), v }
+  end
+end
-- 
1.5.4.3


From 4f69395c02bffeadf978b154ca1ad9e3a57376e0 Mon Sep 17 00:00:00 2001
From: Ryan Angilly <ryan@angilly.com>
Date: Thu, 29 Jan 2009 00:25:14 -0500
Subject: [PATCH] Adding tests for case where object does not respond to blank

---
 activesupport/test/core_ext/or_if_blank_test.rb |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/activesupport/test/core_ext/or_if_blank_test.rb b/activesupport/test/core_ext/or_if_blank_test.rb
index 240bc6b..e5fb785 100644
--- a/activesupport/test/core_ext/or_if_blank_test.rb
+++ b/activesupport/test/core_ext/or_if_blank_test.rb
@@ -1,5 +1,9 @@
 require 'abstract_unit'
 
+class NoBlank
+  undef blank?
+end
+
 class OrIfBlankTest < Test::Unit::TestCase
   BLANK = ["", [], {}, nil, false]
   NOT = ["a", [1,2], {:a => 2}, true, 0]
@@ -10,4 +14,10 @@ class OrIfBlankTest < Test::Unit::TestCase
     BLANK.each { |v| assert_equal v.or_if_blank(substitute), substitute }
     NOT.each { |v| assert_equal v.or_if_blank(substitute), v }
   end
+
+  def test_when_blank_not_defined
+    a = NoBlank.new
+    assert !a.respond_to?(:blank?)
+    assert_equal a.or_if_blank("string"), a
+  end
 end
-- 
1.5.4.3


From 83f2a4124a21f18a5536acf64ad81f911c9487f8 Mon Sep 17 00:00:00 2001
From: Ryan Angilly <ryan@angilly.com>
Date: Thu, 29 Jan 2009 08:05:00 -0500
Subject: [PATCH] adding block option to or_if_blank

---
 .../lib/active_support/core_ext/or_if_blank.rb     |    8 +++-
 activesupport/test/core_ext/or_if_blank_test.rb    |   39 +++++++++++++++++++-
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/activesupport/lib/active_support/core_ext/or_if_blank.rb b/activesupport/lib/active_support/core_ext/or_if_blank.rb
index 0ebc311..2541186 100644
--- a/activesupport/lib/active_support/core_ext/or_if_blank.rb
+++ b/activesupport/lib/active_support/core_ext/or_if_blank.rb
@@ -7,11 +7,15 @@ class Object
   # 
   #   self.email.or_if_blank self.name
   #
+  # or for lazy evaluation:
+  #
+  #   self.email.or_if_blank { self.name }
+  #
   # It will work on any object that implements blank?
 
-  def or_if_blank(val)
+  def or_if_blank(val = nil)
     if respond_to? :blank?
-      self.blank? ? val : self
+      self.blank? ? (val || yield) : self
     else
       self
     end
diff --git a/activesupport/test/core_ext/or_if_blank_test.rb b/activesupport/test/core_ext/or_if_blank_test.rb
index e5fb785..c2bbb37 100644
--- a/activesupport/test/core_ext/or_if_blank_test.rb
+++ b/activesupport/test/core_ext/or_if_blank_test.rb
@@ -4,9 +4,21 @@ class NoBlank
   undef blank?
 end
 
+class SampleObj
+  attr_accessor :a
+
+  def initialize(options)
+    self.a = options[:a]
+  end
+
+  def blank?
+    self.a == ""
+  end
+end
+
 class OrIfBlankTest < Test::Unit::TestCase
-  BLANK = ["", [], {}, nil, false]
-  NOT = ["a", [1,2], {:a => 2}, true, 0]
+  BLANK = ["", [], {}, nil, false, SampleObj.new(:a => "")]
+  NOT = ["a", [1,2], {:a => 2}, true, 0, SampleObj.new(:a => "something")]
 
   def test_or_if_blank
     substitute = "substitute me!"
@@ -20,4 +32,27 @@ class OrIfBlankTest < Test::Unit::TestCase
     assert !a.respond_to?(:blank?)
     assert_equal a.or_if_blank("string"), a
   end
+
+  def test_takes_block
+    substitute = "substitute me!"
+
+    BLANK.each { |v| assert_equal v.or_if_blank {substitute}, substitute }
+    NOT.each { |v| assert_equal v.or_if_blank {substitute}, v }
+  end
+
+  def test_block_computation_can_modifiying_receiver
+    blank_obj = SampleObj.new(:a => "")
+    assert blank_obj.blank?
+    assert_equal blank_obj.or_if_blank { blank_obj.a << "1" }, "1"
+    assert !blank_obj.blank?
+  end
+
+  def test_block_evaluates_lazily
+    orig_value = "a"
+    full_obj = SampleObj.new(:a => orig_value)
+    assert !full_obj.blank?
+    assert_equal full_obj.or_if_blank { full_obj.a << "1" }, full_obj
+    assert_equal full_obj.a, orig_value
+  end
+
 end
-- 
1.5.4.3