JSON: split encoding and coercion

15 files changed, 240 insertions, 211 deletions

diff --git a/activesupport/lib/active_support/json/decoding.rb b/activesupport/lib/active_support/json/decoding.rb
new file mode 100644
index 0000000000..5d4caa362f
--- /dev/null
+++ b/activesupport/lib/active_support/json/decoding.rb
@@ -0,0 +1,35 @@
+require 'active_support/core_ext/module/attribute_accessors'
+
+module ActiveSupport
+  # Look for and parse json strings that look like ISO 8601 times.
+  mattr_accessor :parse_json_times
+
+  module JSON
+    class << self
+      delegate :decode, :to => :backend
+
+      def backend
+        @backend || begin
+          self.backend = "Yaml"
+          @backend
+        end
+      end
+
+      def backend=(name)
+        if name.is_a?(Module)
+          @backend = name
+        else
+          require "active_support/json/backends/#{name.to_s.downcase}.rb"
+          @backend = ActiveSupport::JSON::Backends::const_get(name)
+        end
+      end
+
+      def with_backend(name)
+        old_backend, self.backend = backend, name
+        yield
+      ensure
+        self.backend = old_backend
+      end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/json/encoders/date.rb b/activesupport/lib/active_support/json/encoders/date.rb
deleted file mode 100644
index 9adb3c20e2..0000000000
--- a/activesupport/lib/active_support/json/encoders/date.rb
+++ /dev/null
@@ -1,22 +0,0 @@
-class Date
-  private
-    # Returns a JSON string representing the date. If ActiveSupport.use_standard_json_time_format is set to true, the
-    # ISO 8601 format is used.
-    #
-    # ==== Examples
-    #
-    #   # With ActiveSupport.use_standard_json_time_format = true
-    #   Date.new(2005,2,1).to_json
-    #   # => "2005-02-01"
-    #
-    #   # With ActiveSupport.use_standard_json_time_format = false
-    #   Date.new(2005,2,1).to_json
-    #   # => "2005/02/01"
-    def rails_to_json(*)
-      if ActiveSupport.use_standard_json_time_format
-        %("#{strftime("%Y-%m-%d")}")
-      else
-        %("#{strftime("%Y/%m/%d")}")
-      end
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/date_time.rb b/activesupport/lib/active_support/json/encoders/date_time.rb
deleted file mode 100644
index 3a29292b24..0000000000
--- a/activesupport/lib/active_support/json/encoders/date_time.rb
+++ /dev/null
@@ -1,22 +0,0 @@
-class DateTime
-  private
-    # Returns a JSON string representing the datetime. If ActiveSupport.use_standard_json_time_format is set to true, the
-    # ISO 8601 format is used.
-    #
-    # ==== Examples
-    #
-    #   # With ActiveSupport.use_standard_json_time_format = true
-    #   DateTime.civil(2005,2,1,15,15,10).to_json
-    #   # => "2005-02-01T15:15:10+00:00"
-    #
-    #   # With ActiveSupport.use_standard_json_time_format = false
-    #   DateTime.civil(2005,2,1,15,15,10).to_json
-    #   # => "2005/02/01 15:15:10 +0000"
-    def rails_to_json(*)
-      if ActiveSupport.use_standard_json_time_format
-        xmlschema.inspect
-      else
-        strftime('"%Y/%m/%d %H:%M:%S %z"')
-      end
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/enumerable.rb b/activesupport/lib/active_support/json/encoders/enumerable.rb
deleted file mode 100644
index 898990a59c..0000000000
--- a/activesupport/lib/active_support/json/encoders/enumerable.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-module Enumerable
-  private
-    # Returns a JSON string representing the enumerable. Any +options+
-    # given will be passed on to its elements. For example:
-    #
-    #   users = User.find(:all)
-    #   # => users.to_json(:only => :name)
-    #
-    # will pass the <tt>:only => :name</tt> option to each user.
-    def rails_to_json(options = nil, *args) #:nodoc:
-      "[#{map { |value| ActiveSupport::JSON.encode(value, options, *args) } * ','}]"
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/false_class.rb b/activesupport/lib/active_support/json/encoders/false_class.rb
deleted file mode 100644
index eb975fe542..0000000000
--- a/activesupport/lib/active_support/json/encoders/false_class.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class FalseClass
-  private
-    def rails_to_json(*)
-      'false'
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/hash.rb b/activesupport/lib/active_support/json/encoders/hash.rb
deleted file mode 100644
index 4771484843..0000000000
--- a/activesupport/lib/active_support/json/encoders/hash.rb
+++ /dev/null
@@ -1,51 +0,0 @@
-require 'active_support/core_ext/array/wrap'
-
-class Hash
-  private
-    # Returns a JSON string representing the hash.
-    #
-    # Without any +options+, the returned JSON string will include all
-    # the hash keys. For example:
-    #
-    #   { :name => "Konata Izumi", 'age' => 16, 1 => 2 }.to_json
-    #   # => {"name": "Konata Izumi", "1": 2, "age": 16}
-    #
-    # The keys in the JSON string are unordered due to the nature of hashes.
-    #
-    # The <tt>:only</tt> and <tt>:except</tt> options can be used to limit the
-    # attributes included, and will accept 1 or more hash keys to include/exclude.
-    #
-    #   { :name => "Konata Izumi", 'age' => 16, 1 => 2 }.to_json(:only => [:name, 'age'])
-    #   # => {"name": "Konata Izumi", "age": 16}
-    #
-    #   { :name => "Konata Izumi", 'age' => 16, 1 => 2 }.to_json(:except => 1)
-    #   # => {"name": "Konata Izumi", "age": 16}
-    #
-    # The +options+ also filter down to any hash values. This is particularly
-    # useful for converting hashes containing ActiveRecord objects or any object
-    # that responds to options in their <tt>to_json</tt> method. For example:
-    #
-    #   users = User.find(:all)
-    #   { :users => users, :count => users.size }.to_json(:include => :posts)
-    #
-    # would pass the <tt>:include => :posts</tt> option to <tt>users</tt>,
-    # allowing the posts association in the User model to be converted to JSON
-    # as well.
-    def rails_to_json(options = nil, *args) #:nodoc:
-      hash_keys = self.keys
-
-      if options
-        if except = options[:except]
-          hash_keys = hash_keys - Array.wrap(except)
-        elsif only = options[:only]
-          hash_keys = hash_keys & Array.wrap(only)
-        end
-      end
-
-      result = '{'
-      result << hash_keys.map do |key|
-        "#{ActiveSupport::JSON.encode(key.to_s)}:#{ActiveSupport::JSON.encode(self[key], options, *args)}"
-      end * ','
-      result << '}'
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/nil_class.rb b/activesupport/lib/active_support/json/encoders/nil_class.rb
deleted file mode 100644
index 8c51dba384..0000000000
--- a/activesupport/lib/active_support/json/encoders/nil_class.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class NilClass
-  private
-    def rails_to_json(*)
-      'null'
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/numeric.rb b/activesupport/lib/active_support/json/encoders/numeric.rb
deleted file mode 100644
index c7cd0df1d7..0000000000
--- a/activesupport/lib/active_support/json/encoders/numeric.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class Numeric
-  private
-    def rails_to_json(*)
-      to_s
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/object.rb b/activesupport/lib/active_support/json/encoders/object.rb
deleted file mode 100644
index 9cc12d91ac..0000000000
--- a/activesupport/lib/active_support/json/encoders/object.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-require 'active_support/core_ext/object/instance_variables'
-
-class Object
-  # Dumps object in JSON (JavaScript Object Notation). See www.json.org for more info.
-  def to_json(options = nil)
-    ActiveSupport::JSON.encode(self, options)
-  end
-
-  private
-    def rails_to_json(*args)
-      ActiveSupport::JSON.encode(instance_values, *args)
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/regexp.rb b/activesupport/lib/active_support/json/encoders/regexp.rb
deleted file mode 100644
index ee42db4d02..0000000000
--- a/activesupport/lib/active_support/json/encoders/regexp.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class Regexp
-  private
-    def rails_to_json(*)
-      inspect
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/string.rb b/activesupport/lib/active_support/json/encoders/string.rb
deleted file mode 100644
index 4a6b21c1c0..0000000000
--- a/activesupport/lib/active_support/json/encoders/string.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class String
-  private
-    def rails_to_json(*)
-      ActiveSupport::JSON::Encoding.escape(self)
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/symbol.rb b/activesupport/lib/active_support/json/encoders/symbol.rb
deleted file mode 100644
index d575350a4e..0000000000
--- a/activesupport/lib/active_support/json/encoders/symbol.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class Symbol
-  private
-    def rails_to_json(*args)
-      ActiveSupport::JSON.encode(to_s, *args)
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/time.rb b/activesupport/lib/active_support/json/encoders/time.rb
deleted file mode 100644
index d434b9aace..0000000000
--- a/activesupport/lib/active_support/json/encoders/time.rb
+++ /dev/null
@@ -1,24 +0,0 @@
-require 'active_support/core_ext/time/conversions'
-
-class Time
-  private
-    # Returns a JSON string representing the time. If ActiveSupport.use_standard_json_time_format is set to true, the
-    # ISO 8601 format is used.
-    #
-    # ==== Examples
-    #
-    #   # With ActiveSupport.use_standard_json_time_format = true
-    #   Time.utc(2005,2,1,15,15,10).to_json
-    #   # => "2005-02-01T15:15:10Z"
-    #
-    #   # With ActiveSupport.use_standard_json_time_format = false
-    #   Time.utc(2005,2,1,15,15,10).to_json
-    #   # => "2005/02/01 15:15:10 +0000"
-    def rails_to_json(*)
-      if ActiveSupport.use_standard_json_time_format
-        xmlschema.inspect
-      else
-        %("#{strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)}")
-      end
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoders/true_class.rb b/activesupport/lib/active_support/json/encoders/true_class.rb
deleted file mode 100644
index bc25a6db78..0000000000
--- a/activesupport/lib/active_support/json/encoders/true_class.rb
+++ /dev/null
@@ -1,6 +0,0 @@
-class TrueClass
-  private
-    def rails_to_json(*)
-      'true'
-    end
-end
diff --git a/activesupport/lib/active_support/json/encoding.rb b/activesupport/lib/active_support/json/encoding.rb
index 5fefe5b88b..97e573f7a6 100644
--- a/activesupport/lib/active_support/json/encoding.rb
+++ b/activesupport/lib/active_support/json/encoding.rb
@@ -1,33 +1,214 @@
+require 'active_support/core_ext/array/wrap'
+require 'active_support/core_ext/module/delegation'
+require 'active_support/core_ext/object/instance_variables'
+require 'active_support/deprecation'
+
+# Hack to load json gem first so we can overwrite its to_json.
+begin
+  require 'json'
+rescue LoadError
+end
+
 module ActiveSupport
+  class << self
+    delegate :use_standard_json_time_format, :use_standard_json_time_format=,
+      :escape_html_entities_in_json, :escape_html_entities_in_json=,
+      :to => :'ActiveSupport::JSON::Encoding'
+  end
+
   module JSON
-    class CircularReferenceError < StandardError
+    # matches YAML-formatted dates
+    DATE_REGEX = /^(?:\d{4}-\d{2}-\d{2}|\d{4}-\d{1,2}-\d{1,2}[ \t]+\d{1,2}:\d{2}:\d{2}(\.[0-9]*)?(([ \t]*)Z|[-+]\d{2}?(:\d{2})?))$/
+
+    # Dumps object in JSON (JavaScript Object Notation). See www.json.org for more info.
+    def self.encode(value, options = nil)
+      Encoding::Encoder.new(options).encode(value)
     end
 
-    # Converts a Ruby object into a JSON string.
-    def self.encode(value, options = nil, seen = nil)
-      seen ||= []
-      if seen.any? { |object| object.equal?(value) }
-        raise CircularReferenceError, 'object references itself'
+    module Encoding #:nodoc:
+      class CircularReferenceError < StandardError; end
+
+      class Encoder
+        attr_reader :options
+
+        def initialize(options = nil)
+          @options = options
+          @seen = []
+        end
+
+        def encode(value)
+          check_for_circular_references(value) do
+            value.as_json(options).encode_json(self)
+          end
+        end
+
+        def escape(string)
+          Encoding.escape(string)
+        end
+
+        private
+          def check_for_circular_references(value)
+            if @seen.any? { |object| object.equal?(value) }
+              raise CircularReferenceError, 'object references itself'
+            end
+            @seen.unshift value
+            yield
+          ensure
+            @seen.shift
+          end
+      end
+
+
+      ESCAPED_CHARS = {
+        "\010" =>  '\b',
+        "\f"   =>  '\f',
+        "\n"   =>  '\n',
+        "\r"   =>  '\r',
+        "\t"   =>  '\t',
+        '"'    =>  '\"',
+        '\\'   =>  '\\\\',
+        '>'    =>  '\u003E',
+        '<'    =>  '\u003C',
+        '&'    =>  '\u0026' }
+
+      class << self
+        # If true, use ISO 8601 format for dates and times. Otherwise, fall back to the Active Support legacy format.
+        attr_accessor :use_standard_json_time_format
+
+        attr_accessor :escape_regex
+        attr_reader :escape_html_entities_in_json
+
+        def escape_html_entities_in_json=(value)
+          self.escape_regex = \
+            if @escape_html_entities_in_json = value
+              /[\010\f\n\r\t"\\><&]/
+            else
+              /[\010\f\n\r\t"\\]/
+            end
+        end
+
+        def escape(string)
+          json = '"' + string.gsub(escape_regex) { |s| ESCAPED_CHARS[s] }
+          json.force_encoding('ascii-8bit') if respond_to?(:force_encoding)
+          json.gsub(/([\xC0-\xDF][\x80-\xBF]|
+                   [\xE0-\xEF][\x80-\xBF]{2}|
+                   [\xF0-\xF7][\x80-\xBF]{3})+/nx) { |s|
+            s.unpack("U*").pack("n*").unpack("H*")[0].gsub(/.{4}/, '\\\\u\&')
+          } + '"'
+        end
+      end
+
+      self.escape_html_entities_in_json = true
+    end
+
+    CircularReferenceError = Deprecation::DeprecatedConstantProxy.new('ActiveSupport::JSON::CircularReferenceError', Encoding::CircularReferenceError)
+  end
+end
+
+class Object
+  # Dumps object in JSON (JavaScript Object Notation). See www.json.org for more info.
+  def to_json(options = nil)
+    ActiveSupport::JSON.encode(self, options)
+  end
+
+  def as_json(options = nil) instance_values end #:nodoc:
+end
+
+# A string that returns itself as its JSON-encoded form.
+class ActiveSupport::JSON::Variable < String
+  def as_json(options = nil) self end #:nodoc:
+  def encode_json(encoder) self end #:nodoc:
+end
+
+class TrueClass
+  AS_JSON = ActiveSupport::JSON::Variable.new('true').freeze
+  def as_json(options = nil) AS_JSON end #:nodoc:
+end
+
+class FalseClass
+  AS_JSON = ActiveSupport::JSON::Variable.new('false').freeze
+  def as_json(options = nil) AS_JSON end #:nodoc:
+end
+
+class NilClass
+  AS_JSON = ActiveSupport::JSON::Variable.new('null').freeze
+  def as_json(options = nil) AS_JSON end #:nodoc:
+end
+
+class String
+  def as_json(options = nil) self end #:nodoc:
+  def encode_json(encoder) encoder.escape(self) end #:nodoc:
+end
+
+class Symbol
+  def as_json(options = nil) to_s end #:nodoc:
+end
+
+class Numeric
+  def as_json(options = nil) self end #:nodoc:
+  def encode_json(encoder) to_s end #:nodoc:
+end
+
+class Regexp
+  def as_json(options = nil) self end #:nodoc:
+  def encode_json(encoder) inspect end #:nodoc:
+end
+
+module Enumerable
+  def as_json(options = nil) to_a end #:nodoc:
+end
+
+class Array
+  def as_json(options = nil) self end #:nodoc:
+  def encode_json(encoder) "[#{map { |v| encoder.encode(v) } * ','}]" end #:nodoc:
+end
+
+class Hash
+  def as_json(options = nil) #:nodoc:
+    if options
+      if attrs = options[:only]
+        slice(*Array.wrap(attrs))
+      elsif attrs = options[:except]
+        except(*Array.wrap(attrs))
+      else
+        self
       end
-      seen << value
-      value.__send__(:rails_to_json, options, seen)
-    ensure
-      seen.pop
+    else
+      self
+    end
+  end
+
+  def encode_json(encoder)
+    "{#{map { |k,v| "#{encoder.encode(k.to_s)}:#{encoder.encode(v)}" } * ','}}"
+  end
+end
+
+class Time
+  def as_json(options = nil) #:nodoc:
+    if ActiveSupport.use_standard_json_time_format
+      xmlschema
+    else
+      %(#{strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)})
     end
   end
 end
 
-require 'active_support/json/variable'
-require 'active_support/json/encoders/date'
-require 'active_support/json/encoders/date_time'
-require 'active_support/json/encoders/enumerable'
-require 'active_support/json/encoders/false_class'
-require 'active_support/json/encoders/hash'
-require 'active_support/json/encoders/nil_class'
-require 'active_support/json/encoders/numeric'
-require 'active_support/json/encoders/object'
-require 'active_support/json/encoders/regexp'
-require 'active_support/json/encoders/string'
-require 'active_support/json/encoders/symbol'
-require 'active_support/json/encoders/time'
-require 'active_support/json/encoders/true_class'
+class Date
+  def as_json(options = nil) #:nodoc:
+    if ActiveSupport.use_standard_json_time_format
+      strftime("%Y-%m-%d")
+    else
+      strftime("%Y/%m/%d")
+    end
+  end
+end
+
+class DateTime
+  def as_json(options = nil) #:nodoc:
+    if ActiveSupport.use_standard_json_time_format
+      xmlschema
+    else
+      strftime('%Y/%m/%d %H:%M:%S %z')
+    end
+  end
+end