Initial Version of Deprecation for Rails[Koz]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4623 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 46 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/deprecation.rb b/activesupport/lib/active_support/deprecation.rb
new file mode 100644
index 0000000000..a72b12bcfe
--- /dev/null
+++ b/activesupport/lib/active_support/deprecation.rb
@@ -0,0 +1,46 @@
+module ActiveSupport
+  module Deprecation
+    @@warning_method = :print
+    mattr_accessor :warning_method
+    
+    class << self
+
+      def print_warning(lines)
+        lines.each {|l| $stderr.write("#{l}\n")}
+      end
+      
+      def log_warning(lines)
+        if Object.const_defined?("RAILS_DEFAULT_LOGGER")
+          lines.each {|l| RAILS_DEFAULT_LOGGER.warn l}
+        else
+          print_warning(lines)
+        end
+      end
+      
+      def issue_warning(line)
+        lines = 
+        ["@@@@@@@@@@ Deprecation Warning @@@@@@@@@@", line,
+         "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"]
+        self.send("#{@@warning_method}_warning", lines)
+      end
+      
+      def instance_method_warning(clazz, method)
+        issue_warning("Your application calls #{clazz}##{method}, which is now deprecated.  Please see the API documents at http://api.rubyonrails.org/ for more information.")
+      end
+    end
+    
+    module ClassMethods
+      def deprecate(method_name)
+        alias_method "#{method_name}_before_deprecation", method_name
+        class_eval(<<-EOS, __FILE__, __LINE__)
+        def #{method_name}(*args)
+          ::ActiveSupport::Deprecation.instance_method_warning(self.class, :#{method_name})
+          #{method_name}_before_deprecation *args
+        end
+        EOS
+      end
+    end
+  end
+end
+
+Object.extend(ActiveSupport::Deprecation::ClassMethods)