Add ActiveSupport::JSON and Object#to_json for converting Ruby objects to JSON strings

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3356 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 61 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/json/encoders/core.rb b/activesupport/lib/active_support/json/encoders/core.rb
new file mode 100644
index 0000000000..003c938be4
--- /dev/null
+++ b/activesupport/lib/active_support/json/encoders/core.rb
@@ -0,0 +1,61 @@
+module ActiveSupport
+  module JSON #:nodoc:
+    module Encoders
+      define_encoder Object do |object|
+        object.instance_values.to_json
+      end
+      
+      define_encoder TrueClass do
+        'true'
+      end
+      
+      define_encoder FalseClass do
+        'false'
+      end
+      
+      define_encoder NilClass do
+        'null'
+      end
+      
+      define_encoder String do |string|
+        returning value = '"' do
+          string.each_char do |char|
+            value << case
+            when char == "\010":  '\b'
+            when char == "\f":    '\f'
+            when char == "\n":    '\n'
+            when char == "\r":    '\r'
+            when char == "\t":    '\t'
+            when char == '"':     '\"'
+            when char == '\\':    '\\\\'  
+            when char.length > 1: "\\u#{'%04x' % char.unpack('U').first}"
+            else;                 char
+            end
+          end
+          value << '"'
+        end
+      end
+      
+      define_encoder Numeric do |numeric|
+        numeric.to_s
+      end
+      
+      define_encoder Symbol do |symbol|
+        symbol.to_s.to_json
+      end
+
+      define_encoder Enumerable do |enumerable|
+        "[#{enumerable.map { |value| value.to_json } * ', '}]"
+      end
+      
+      define_encoder Hash do |hash|
+        returning result = '{' do
+          result << hash.map do |pair|
+            pair.map { |value| value.to_json } * ': '
+          end * ', '
+          result << '}'
+        end
+      end
+    end
+  end
+end