Merge pull request rails#12203 from chancancode/eager_load_json

Eagerload active_support/json/encoding in active_support/core_ext/object/to_json

Author: jeremy

activesupport/lib/active_support/core_ext/object.rb

@@ -8,7 +8,7 @@
 require 'active_support/core_ext/object/conversions'
 require 'active_support/core_ext/object/instance_variables'
 
-require 'active_support/core_ext/object/to_json'
+require 'active_support/core_ext/object/json'
 require 'active_support/core_ext/object/to_param'
 require 'active_support/core_ext/object/to_query'
 require 'active_support/core_ext/object/with_options'

activesupport/lib/active_support/core_ext/object/json.rb

@@ -0,0 +1,216 @@
+# Hack to load json gem first so we can overwrite its to_json.
+require 'json'
+
+# The JSON gem adds a few modules to Ruby core classes containing :to_json definition, overwriting
+# their default behavior. That said, we need to define the basic to_json method in all of them,
+# otherwise they will always use to_json gem implementation, which is backwards incompatible in
+# several cases (for instance, the JSON implementation for Hash does not work) with inheritance
+# and consequently classes as ActiveSupport::OrderedHash cannot be serialized to json.
+[Object, Array, FalseClass, Float, Hash, Integer, NilClass, String, TrueClass].each do |klass|
+  klass.class_eval do
+    # 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
+  end
+end
+
+class Object
+  def as_json(options = nil) #:nodoc:
+    if respond_to?(:to_hash)
+      to_hash
+    else
+      instance_values
+    end
+  end
+end
+
+class Struct #:nodoc:
+  def as_json(options = nil)
+    Hash[members.zip(values)]
+  end
+end
+
+class TrueClass
+  def as_json(options = nil) #:nodoc:
+    self
+  end
+
+  def encode_json(encoder) #:nodoc:
+    to_s
+  end
+end
+
+class FalseClass
+  def as_json(options = nil) #:nodoc:
+    self
+  end
+
+  def encode_json(encoder) #:nodoc:
+    to_s
+  end
+end
+
+class NilClass
+  def as_json(options = nil) #:nodoc:
+    self
+  end
+
+  def encode_json(encoder) #:nodoc:
+    'null'
+  end
+end
+
+class String
+  def as_json(options = nil) #:nodoc:
+    self
+  end
+
+  def encode_json(encoder) #:nodoc:
+    encoder.escape(self)
+  end
+end
+
+class Symbol
+  def as_json(options = nil) #:nodoc:
+    to_s
+  end
+end
+
+class Numeric
+  def as_json(options = nil) #:nodoc:
+    self
+  end
+
+  def encode_json(encoder) #:nodoc:
+    to_s
+  end
+end
+
+class Float
+  # Encoding Infinity or NaN to JSON should return "null". The default returns
+  # "Infinity" or "NaN" which breaks parsing the JSON. E.g. JSON.parse('[NaN]').
+  def as_json(options = nil) #:nodoc:
+    finite? ? self : nil
+  end
+end
+
+class BigDecimal
+  # A BigDecimal would be naturally represented as a JSON number. Most libraries,
+  # however, parse non-integer JSON numbers directly as floats. Clients using
+  # those libraries would get in general a wrong number and no way to recover
+  # other than manually inspecting the string with the JSON code itself.
+  #
+  # That's why a JSON string is returned. The JSON literal is not numeric, but
+  # if the other end knows by contract that the data is supposed to be a
+  # BigDecimal, it still has the chance to post-process the string and get the
+  # real value.
+  #
+  # Use <tt>ActiveSupport.use_standard_json_big_decimal_format = true</tt> to
+  # override this behavior.
+  def as_json(options = nil) #:nodoc:
+    if finite?
+      ActiveSupport.encode_big_decimal_as_string ? to_s : self
+    else
+      nil
+    end
+  end
+end
+
+class Regexp
+  def as_json(options = nil) #:nodoc:
+    to_s
+  end
+end
+
+module Enumerable
+  def as_json(options = nil) #:nodoc:
+    to_a.as_json(options)
+  end
+end
+
+class Range
+  def as_json(options = nil) #:nodoc:
+    to_s
+  end
+end
+
+class Array
+  def as_json(options = nil) #:nodoc:
+    # use encoder as a proxy to call as_json on all elements, to protect from circular references
+    encoder = options && options[:encoder] || ActiveSupport::JSON::Encoding::Encoder.new(options)
+    map { |v| encoder.as_json(v, options) }
+  end
+
+  def encode_json(encoder) #:nodoc:
+    # we assume here that the encoder has already run as_json on self and the elements, so we run encode_json directly
+    "[#{map { |v| v.encode_json(encoder) } * ','}]"
+  end
+end
+
+class Hash
+  def as_json(options = nil) #:nodoc:
+    # create a subset of the hash by applying :only or :except
+    subset = if options
+      if attrs = options[:only]
+        slice(*Array(attrs))
+      elsif attrs = options[:except]
+        except(*Array(attrs))
+      else
+        self
+      end
+    else
+      self
+    end
+
+    # use encoder as a proxy to call as_json on all values in the subset, to protect from circular references
+    encoder = options && options[:encoder] || ActiveSupport::JSON::Encoding::Encoder.new(options)
+    Hash[subset.map { |k, v| [k.to_s, encoder.as_json(v, options)] }]
+  end
+
+  def encode_json(encoder) #:nodoc:
+    # values are encoded with use_options = false, because we don't want hash representations from ActiveModel to be
+    # processed once again with as_json with options, as this could cause unexpected results (i.e. missing fields);
+
+    # on the other hand, we need to run as_json on the elements, because the model representation may contain fields
+    # like Time/Date in their original (not jsonified) form, etc.
+
+    "{#{map { |k,v| "#{encoder.encode(k.to_s)}:#{encoder.encode(v, false)}" } * ','}}"
+  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
+
+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
+
+class Process::Status
+  def as_json(options = nil)
+    { :exitstatus => exitstatus, :pid => pid }
+  end
+end

activesupport/lib/active_support/core_ext/object/to_json.rb

@@ -1,27 +1,5 @@
-# Hack to load json gem first so we can overwrite its to_json.
-begin
-  require 'json'
-rescue LoadError
-end
+ActiveSupport::Deprecation.warn 'You have required `active_support/core_ext/object/to_json`. ' \
+  'This file will be removed in Rails 4.2. You should require `active_support/core_ext/object/json` ' \
+  'instead.'
 
-# The JSON gem adds a few modules to Ruby core classes containing :to_json definition, overwriting
-# their default behavior. That said, we need to define the basic to_json method in all of them,
-# otherwise they will always use to_json gem implementation, which is backwards incompatible in
-# several cases (for instance, the JSON implementation for Hash does not work) with inheritance
-# and consequently classes as ActiveSupport::OrderedHash cannot be serialized to json.
-[Object, Array, FalseClass, Float, Hash, Integer, NilClass, String, TrueClass].each do |klass|
-  klass.class_eval do
-    # 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
-  end
-end
-
-module Process
-  class Status
-    def as_json(options = nil)
-      { :exitstatus => exitstatus, :pid => pid }
-    end
-  end
-end
+require 'active_support/core_ext/object/json'