blank? and duplicable? are Object extensions

2 files changed, 101 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/core_ext/object/blank.rb b/activesupport/lib/active_support/core_ext/object/blank.rb
new file mode 100644
index 0000000000..9a1f663bf3
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/object/blank.rb
@@ -0,0 +1,58 @@
+class Object
+  # An object is blank if it's false, empty, or a whitespace string.
+  # For example, "", "   ", +nil+, [], and {} are blank.
+  #
+  # This simplifies
+  #
+  #   if !address.nil? && !address.empty?
+  #
+  # to
+  #
+  #   if !address.blank?
+  def blank?
+    respond_to?(:empty?) ? empty? : !self
+  end
+
+  # An object is present if it's not blank.
+  def present?
+    !blank?
+  end
+end
+
+class NilClass #:nodoc:
+  def blank?
+    true
+  end
+end
+
+class FalseClass #:nodoc:
+  def blank?
+    true
+  end
+end
+
+class TrueClass #:nodoc:
+  def blank?
+    false
+  end
+end
+
+class Array #:nodoc:
+  alias_method :blank?, :empty?
+end
+
+class Hash #:nodoc:
+  alias_method :blank?, :empty?
+end
+
+class String #:nodoc:
+  def blank?
+    self !~ /\S/
+  end
+end
+
+class Numeric #:nodoc:
+  def blank?
+    false
+  end
+end
diff --git a/activesupport/lib/active_support/core_ext/object/duplicable.rb b/activesupport/lib/active_support/core_ext/object/duplicable.rb
new file mode 100644
index 0000000000..8f49ddfd9e
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/object/duplicable.rb
@@ -0,0 +1,43 @@
+class Object
+  # Can you safely .dup this object?
+  # False for nil, false, true, symbols, and numbers; true otherwise.
+  def duplicable?
+    true
+  end
+end
+
+class NilClass #:nodoc:
+  def duplicable?
+    false
+  end
+end
+
+class FalseClass #:nodoc:
+  def duplicable?
+    false
+  end
+end
+
+class TrueClass #:nodoc:
+  def duplicable?
+    false
+  end
+end
+
+class Symbol #:nodoc:
+  def duplicable?
+    false
+  end
+end
+
+class Numeric #:nodoc:
+  def duplicable?
+    false
+  end
+end
+
+class Class #:nodoc:
+  def duplicable?
+    false
+  end
+end