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-rw-r--r--activesupport/lib/active_support/core_ext/object/acts_like.rb8
-rw-r--r--activesupport/lib/active_support/core_ext/object/blank.rb60
-rw-r--r--activesupport/lib/active_support/core_ext/object/deep_dup.rb14
-rw-r--r--activesupport/lib/active_support/core_ext/object/duplicable.rb15
-rw-r--r--activesupport/lib/active_support/core_ext/object/inclusion.rb40
-rw-r--r--activesupport/lib/active_support/core_ext/object/instance_variables.rb4
-rw-r--r--activesupport/lib/active_support/core_ext/object/json.rb197
-rw-r--r--activesupport/lib/active_support/core_ext/object/to_json.rb27
-rw-r--r--activesupport/lib/active_support/core_ext/object/to_param.rb59
-rw-r--r--activesupport/lib/active_support/core_ext/object/to_query.rb73
-rw-r--r--activesupport/lib/active_support/core_ext/object/try.rb94
-rw-r--r--activesupport/lib/active_support/core_ext/object/with_options.rb33
12 files changed, 446 insertions, 178 deletions
diff --git a/activesupport/lib/active_support/core_ext/object/acts_like.rb b/activesupport/lib/active_support/core_ext/object/acts_like.rb
index fcc8e50f06..3912cc5ace 100644
--- a/activesupport/lib/active_support/core_ext/object/acts_like.rb
+++ b/activesupport/lib/active_support/core_ext/object/acts_like.rb
@@ -1,9 +1,9 @@
class Object
# A duck-type assistant method. For example, Active Support extends Date
- # to define an acts_like_date? method, and extends Time to define
- # acts_like_time?. As a result, we can do "x.acts_like?(:time)" and
- # "x.acts_like?(:date)" to do duck-type-safe comparisons, since classes that
- # we want to act like Time simply need to define an acts_like_time? method.
+ # to define an <tt>acts_like_date?</tt> method, and extends Time to define
+ # <tt>acts_like_time?</tt>. As a result, we can do <tt>x.acts_like?(:time)</tt> and
+ # <tt>x.acts_like?(:date)</tt> to do duck-type-safe comparisons, since classes that
+ # we want to act like Time simply need to define an <tt>acts_like_time?</tt> method.
def acts_like?(duck)
respond_to? :"acts_like_#{duck}?"
end
diff --git a/activesupport/lib/active_support/core_ext/object/blank.rb b/activesupport/lib/active_support/core_ext/object/blank.rb
index 8a5eb4bc93..38e43478df 100644
--- a/activesupport/lib/active_support/core_ext/object/blank.rb
+++ b/activesupport/lib/active_support/core_ext/object/blank.rb
@@ -4,36 +4,42 @@ class Object
# An object is blank if it's false, empty, or a whitespace string.
# For example, '', ' ', +nil+, [], and {} are all blank.
#
- # This simplifies:
+ # This simplifies
#
- # if address.nil? || address.empty?
+ # address.nil? || address.empty?
#
- # ...to:
+ # to
#
- # if address.blank?
+ # address.blank?
+ #
+ # @return [true, false]
def blank?
- respond_to?(:empty?) ? empty? : !self
+ respond_to?(:empty?) ? !!empty? : !self
end
- # An object is present if it's not <tt>blank?</tt>.
+ # An object is present if it's not blank.
+ #
+ # @return [true, false]
def present?
!blank?
end
- # Returns object if it's <tt>present?</tt> otherwise returns +nil+.
- # <tt>object.presence</tt> is equivalent to <tt>object.present? ? object : nil</tt>.
+ # Returns the receiver if it's present otherwise returns +nil+.
+ # <tt>object.presence</tt> is equivalent to
#
- # This is handy for any representation of objects where blank is the same
- # as not present at all. For example, this simplifies a common check for
- # HTTP POST/query parameters:
+ # object.present? ? object : nil
+ #
+ # For example, something like
#
# state = params[:state] if params[:state].present?
# country = params[:country] if params[:country].present?
# region = state || country || 'US'
#
- # ...becomes:
+ # becomes
#
# region = params[:state].presence || params[:country].presence || 'US'
+ #
+ # @return [Object]
def presence
self if present?
end
@@ -43,6 +49,8 @@ class NilClass
# +nil+ is blank:
#
# nil.blank? # => true
+ #
+ # @return [true]
def blank?
true
end
@@ -52,6 +60,8 @@ class FalseClass
# +false+ is blank:
#
# false.blank? # => true
+ #
+ # @return [true]
def blank?
true
end
@@ -61,6 +71,8 @@ class TrueClass
# +true+ is not blank:
#
# true.blank? # => false
+ #
+ # @return [false]
def blank?
false
end
@@ -71,6 +83,8 @@ class Array
#
# [].blank? # => true
# [1,2,3].blank? # => false
+ #
+ # @return [true, false]
alias_method :blank?, :empty?
end
@@ -79,18 +93,28 @@ class Hash
#
# {}.blank? # => true
# { key: 'value' }.blank? # => false
+ #
+ # @return [true, false]
alias_method :blank?, :empty?
end
class String
+ BLANK_RE = /\A[[:space:]]*\z/
+
# A string is blank if it's empty or contains whitespaces only:
#
- # ''.blank? # => true
- # ' '.blank? # => true
- # ' '.blank? # => true
- # ' something here '.blank? # => false
+ # ''.blank? # => true
+ # ' '.blank? # => true
+ # "\t\n\r".blank? # => true
+ # ' blah '.blank? # => false
+ #
+ # Unicode whitespace is supported:
+ #
+ # "\u00a0".blank? # => true
+ #
+ # @return [true, false]
def blank?
- self !~ /[^[:space:]]/
+ BLANK_RE === self
end
end
@@ -99,6 +123,8 @@ class Numeric #:nodoc:
#
# 1.blank? # => false
# 0.blank? # => false
+ #
+ # @return [false]
def blank?
false
end
diff --git a/activesupport/lib/active_support/core_ext/object/deep_dup.rb b/activesupport/lib/active_support/core_ext/object/deep_dup.rb
index 1d639f3af6..0191d2e973 100644
--- a/activesupport/lib/active_support/core_ext/object/deep_dup.rb
+++ b/activesupport/lib/active_support/core_ext/object/deep_dup.rb
@@ -8,8 +8,8 @@ class Object
# dup = object.deep_dup
# dup.instance_variable_set(:@a, 1)
#
- # object.instance_variable_defined?(:@a) #=> false
- # dup.instance_variable_defined?(:@a) #=> true
+ # object.instance_variable_defined?(:@a) # => false
+ # dup.instance_variable_defined?(:@a) # => true
def deep_dup
duplicable? ? dup : self
end
@@ -22,10 +22,10 @@ class Array
# dup = array.deep_dup
# dup[1][2] = 4
#
- # array[1][2] #=> nil
- # dup[1][2] #=> 4
+ # array[1][2] # => nil
+ # dup[1][2] # => 4
def deep_dup
- map { |it| it.deep_dup }
+ map(&:deep_dup)
end
end
@@ -36,8 +36,8 @@ class Hash
# dup = hash.deep_dup
# dup[:a][:c] = 'c'
#
- # hash[:a][:c] #=> nil
- # dup[:a][:c] #=> "c"
+ # hash[:a][:c] # => nil
+ # dup[:a][:c] # => "c"
def deep_dup
each_with_object(dup) do |(key, value), hash|
hash[key.deep_dup] = value.deep_dup
diff --git a/activesupport/lib/active_support/core_ext/object/duplicable.rb b/activesupport/lib/active_support/core_ext/object/duplicable.rb
index 9cd7485e2e..665cb0f96d 100644
--- a/activesupport/lib/active_support/core_ext/object/duplicable.rb
+++ b/activesupport/lib/active_support/core_ext/object/duplicable.rb
@@ -19,7 +19,7 @@
class Object
# Can you safely dup this object?
#
- # False for +nil+, +false+, +true+, symbol, and number objects;
+ # False for +nil+, +false+, +true+, symbol, number and BigDecimal(in 1.9.x) objects;
# true otherwise.
def duplicable?
true
@@ -78,6 +78,9 @@ end
require 'bigdecimal'
class BigDecimal
+ # Needed to support Ruby 1.9.x, as it doesn't allow dup on BigDecimal, instead
+ # raises TypeError exception. Checking here on the runtime whether BigDecimal
+ # will allow dup or not.
begin
BigDecimal.new('4.56').dup
@@ -88,3 +91,13 @@ class BigDecimal
# can't dup, so use superclass implementation
end
end
+
+class Method
+ # Methods are not duplicable:
+ #
+ # method(:puts).duplicable? # => false
+ # method(:puts).dup # => TypeError: allocator undefined for Method
+ def duplicable?
+ false
+ end
+end
diff --git a/activesupport/lib/active_support/core_ext/object/inclusion.rb b/activesupport/lib/active_support/core_ext/object/inclusion.rb
index 3fec465ec0..55f281b213 100644
--- a/activesupport/lib/active_support/core_ext/object/inclusion.rb
+++ b/activesupport/lib/active_support/core_ext/object/inclusion.rb
@@ -1,25 +1,27 @@
class Object
- # Returns true if this object is included in the argument(s). Argument must be
- # any object which responds to +#include?+ or optionally, multiple arguments can be passed in. Usage:
+ # Returns true if this object is included in the argument. Argument must be
+ # any object which responds to +#include?+. Usage:
#
- # characters = ['Konata', 'Kagami', 'Tsukasa']
- # 'Konata'.in?(characters) # => true
+ # characters = ["Konata", "Kagami", "Tsukasa"]
+ # "Konata".in?(characters) # => true
#
- # character = 'Konata'
- # character.in?('Konata', 'Kagami', 'Tsukasa') # => true
- #
- # This will throw an ArgumentError if a single argument is passed in and it doesn't respond
+ # This will throw an ArgumentError if the argument doesn't respond
# to +#include?+.
- def in?(*args)
- if args.length > 1
- args.include? self
- else
- another_object = args.first
- if another_object.respond_to? :include?
- another_object.include? self
- else
- raise ArgumentError.new 'The single parameter passed to #in? must respond to #include?'
- end
- end
+ def in?(another_object)
+ another_object.include?(self)
+ rescue NoMethodError
+ raise ArgumentError.new("The parameter passed to #in? must respond to #include?")
+ end
+
+ # Returns the receiver if it's included in the argument otherwise returns +nil+.
+ # Argument must be any object which responds to +#include?+. Usage:
+ #
+ # params[:bucket_type].presence_in %w( project calendar )
+ #
+ # This will throw an ArgumentError if the argument doesn't respond to +#include?+.
+ #
+ # @return [Object]
+ def presence_in(another_object)
+ self.in?(another_object) ? self : nil
end
end
diff --git a/activesupport/lib/active_support/core_ext/object/instance_variables.rb b/activesupport/lib/active_support/core_ext/object/instance_variables.rb
index 40821fd619..593a7a4940 100644
--- a/activesupport/lib/active_support/core_ext/object/instance_variables.rb
+++ b/activesupport/lib/active_support/core_ext/object/instance_variables.rb
@@ -13,7 +13,7 @@ class Object
Hash[instance_variables.map { |name| [name[1..-1], instance_variable_get(name)] }]
end
- # Returns an array of instance variable names including "@".
+ # Returns an array of instance variable names as strings including "@".
#
# class C
# def initialize(x, y)
@@ -23,6 +23,6 @@ class Object
#
# C.new(0, 1).instance_variable_names # => ["@y", "@x"]
def instance_variable_names
- instance_variables.map { |var| var.to_s }
+ instance_variables.map(&:to_s)
end
end
diff --git a/activesupport/lib/active_support/core_ext/object/json.rb b/activesupport/lib/active_support/core_ext/object/json.rb
new file mode 100644
index 0000000000..698b2d1920
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/object/json.rb
@@ -0,0 +1,197 @@
+# Hack to load json gem first so we can overwrite its to_json.
+require 'json'
+require 'bigdecimal'
+require 'active_support/core_ext/big_decimal/conversions' # for #to_s
+require 'active_support/core_ext/hash/except'
+require 'active_support/core_ext/hash/slice'
+require 'active_support/core_ext/object/instance_variables'
+require 'time'
+require 'active_support/core_ext/time/conversions'
+require 'active_support/core_ext/date_time/conversions'
+require 'active_support/core_ext/date/conversions'
+require 'active_support/core_ext/module/aliasing'
+
+# 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.
+#
+# On the other hand, we should avoid conflict with ::JSON.{generate,dump}(obj). Unfortunately, the
+# JSON gem's encoder relies on its own to_json implementation to encode objects. Since it always
+# passes a ::JSON::State object as the only argument to to_json, we can detect that and forward the
+# calls to the original to_json method.
+#
+# It should be noted that when using ::JSON.{generate,dump} directly, ActiveSupport's encoder is
+# bypassed completely. This means that as_json won't be invoked and the JSON gem will simply
+# ignore any options it does not natively understand. This also means that ::JSON.{generate,dump}
+# should give exactly the same results with or without active support.
+[Object, Array, FalseClass, Float, Hash, Integer, NilClass, String, TrueClass, Enumerable].each do |klass|
+ klass.class_eval do
+ def to_json_with_active_support_encoder(options = nil)
+ if options.is_a?(::JSON::State)
+ # Called from JSON.{generate,dump}, forward it to JSON gem's to_json
+ self.to_json_without_active_support_encoder(options)
+ else
+ # to_json is being invoked directly, use ActiveSupport's encoder
+ ActiveSupport::JSON.encode(self, options)
+ end
+ end
+
+ alias_method_chain :to_json, :active_support_encoder
+ end
+end
+
+class Object
+ def as_json(options = nil) #:nodoc:
+ if respond_to?(:to_hash)
+ to_hash.as_json(options)
+ else
+ instance_values.as_json(options)
+ end
+ end
+end
+
+class Struct #:nodoc:
+ def as_json(options = nil)
+ Hash[members.zip(values)].as_json(options)
+ end
+end
+
+class TrueClass
+ def as_json(options = nil) #:nodoc:
+ self
+ end
+end
+
+class FalseClass
+ def as_json(options = nil) #:nodoc:
+ self
+ end
+end
+
+class NilClass
+ def as_json(options = nil) #:nodoc:
+ self
+ end
+end
+
+class String
+ def as_json(options = nil) #:nodoc:
+ 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
+end
+
+class Float
+ # Encoding Infinity or NaN to JSON should return "null". The default returns
+ # "Infinity" or "NaN" which are not valid JSON.
+ 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.
+ def as_json(options = nil) #:nodoc:
+ finite? ? to_s : nil
+ 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:
+ map { |v| options ? v.as_json(options.dup) : v.as_json }
+ 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
+
+ Hash[subset.map { |k, v| [k.to_s, options ? v.as_json(options.dup) : v.as_json] }]
+ end
+end
+
+class Time
+ def as_json(options = nil) #:nodoc:
+ if ActiveSupport::JSON::Encoding.use_standard_json_time_format
+ xmlschema(ActiveSupport::JSON::Encoding.time_precision)
+ else
+ %(#{strftime("%Y/%m/%d %H:%M:%S")} #{formatted_offset(false)})
+ end
+ end
+end
+
+class Date
+ def as_json(options = nil) #:nodoc:
+ if ActiveSupport::JSON::Encoding.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::JSON::Encoding.use_standard_json_time_format
+ xmlschema(ActiveSupport::JSON::Encoding.time_precision)
+ else
+ strftime('%Y/%m/%d %H:%M:%S %z')
+ end
+ end
+end
+
+class Process::Status #:nodoc:
+ def as_json(options = nil)
+ { :exitstatus => exitstatus, :pid => pid }
+ end
+end
diff --git a/activesupport/lib/active_support/core_ext/object/to_json.rb b/activesupport/lib/active_support/core_ext/object/to_json.rb
deleted file mode 100644
index 83cc8066e7..0000000000
--- a/activesupport/lib/active_support/core_ext/object/to_json.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-# Hack to load json gem first so we can overwrite its to_json.
-begin
- require 'json'
-rescue LoadError
-end
-
-# 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
diff --git a/activesupport/lib/active_support/core_ext/object/to_param.rb b/activesupport/lib/active_support/core_ext/object/to_param.rb
index 0d5f3501e5..684d4ef57e 100644
--- a/activesupport/lib/active_support/core_ext/object/to_param.rb
+++ b/activesupport/lib/active_support/core_ext/object/to_param.rb
@@ -1,58 +1 @@
-class Object
- # Alias of <tt>to_s</tt>.
- def to_param
- to_s
- end
-end
-
-class NilClass
- # Returns +self+.
- def to_param
- self
- end
-end
-
-class TrueClass
- # Returns +self+.
- def to_param
- self
- end
-end
-
-class FalseClass
- # Returns +self+.
- def to_param
- self
- end
-end
-
-class Array
- # Calls <tt>to_param</tt> on all its elements and joins the result with
- # slashes. This is used by <tt>url_for</tt> in Action Pack.
- def to_param
- collect { |e| e.to_param }.join '/'
- end
-end
-
-class Hash
- # Returns a string representation of the receiver suitable for use as a URL
- # query string:
- #
- # {name: 'David', nationality: 'Danish'}.to_param
- # # => "name=David&nationality=Danish"
- #
- # An optional namespace can be passed to enclose the param names:
- #
- # {name: 'David', nationality: 'Danish'}.to_param('user')
- # # => "user[name]=David&user[nationality]=Danish"
- #
- # The string pairs "key=value" that conform the query string
- # are sorted lexicographically in ascending order.
- #
- # This method is also aliased as +to_query+.
- def to_param(namespace = nil)
- collect do |key, value|
- value.to_query(namespace ? "#{namespace}[#{key}]" : key)
- end.sort * '&'
- end
-end
+require 'active_support/core_ext/object/to_query'
diff --git a/activesupport/lib/active_support/core_ext/object/to_query.rb b/activesupport/lib/active_support/core_ext/object/to_query.rb
index 5d5fcf00e0..ec5ace4e16 100644
--- a/activesupport/lib/active_support/core_ext/object/to_query.rb
+++ b/activesupport/lib/active_support/core_ext/object/to_query.rb
@@ -1,27 +1,84 @@
-require 'active_support/core_ext/object/to_param'
+require 'cgi'
class Object
- # Converts an object into a string suitable for use as a URL query string, using the given <tt>key</tt> as the
- # param name.
- #
- # Note: This method is defined as a default implementation for all Objects for Hash#to_query to work.
+ # Alias of <tt>to_s</tt>.
+ def to_param
+ to_s
+ end
+
+ # Converts an object into a string suitable for use as a URL query string,
+ # using the given <tt>key</tt> as the param name.
def to_query(key)
- require 'cgi' unless defined?(CGI) && defined?(CGI::escape)
"#{CGI.escape(key.to_param)}=#{CGI.escape(to_param.to_s)}"
end
end
+class NilClass
+ # Returns +self+.
+ def to_param
+ self
+ end
+end
+
+class TrueClass
+ # Returns +self+.
+ def to_param
+ self
+ end
+end
+
+class FalseClass
+ # Returns +self+.
+ def to_param
+ self
+ end
+end
+
class Array
+ # Calls <tt>to_param</tt> on all its elements and joins the result with
+ # slashes. This is used by <tt>url_for</tt> in Action Pack.
+ def to_param
+ collect(&:to_param).join '/'
+ end
+
# Converts an array into a string suitable for use as a URL query string,
# using the given +key+ as the param name.
#
# ['Rails', 'coding'].to_query('hobbies') # => "hobbies%5B%5D=Rails&hobbies%5B%5D=coding"
def to_query(key)
prefix = "#{key}[]"
- collect { |value| value.to_query(prefix) }.join '&'
+
+ if empty?
+ nil.to_query(prefix)
+ else
+ collect { |value| value.to_query(prefix) }.join '&'
+ end
end
end
class Hash
- alias_method :to_query, :to_param
+ # Returns a string representation of the receiver suitable for use as a URL
+ # query string:
+ #
+ # {name: 'David', nationality: 'Danish'}.to_query
+ # # => "name=David&nationality=Danish"
+ #
+ # An optional namespace can be passed to enclose key names:
+ #
+ # {name: 'David', nationality: 'Danish'}.to_query('user')
+ # # => "user%5Bname%5D=David&user%5Bnationality%5D=Danish"
+ #
+ # The string pairs "key=value" that conform the query string
+ # are sorted lexicographically in ascending order.
+ #
+ # This method is also aliased as +to_param+.
+ def to_query(namespace = nil)
+ collect do |key, value|
+ unless (value.is_a?(Hash) || value.is_a?(Array)) && value.empty?
+ value.to_query(namespace ? "#{namespace}[#{key}]" : key)
+ end
+ end.compact.sort! * '&'
+ end
+
+ alias_method :to_param, :to_query
end
diff --git a/activesupport/lib/active_support/core_ext/object/try.rb b/activesupport/lib/active_support/core_ext/object/try.rb
index 1079ddde98..26b8d58948 100644
--- a/activesupport/lib/active_support/core_ext/object/try.rb
+++ b/activesupport/lib/active_support/core_ext/object/try.rb
@@ -1,48 +1,78 @@
class Object
- # Invokes the public method identified by the symbol +method+, passing it any arguments
- # and/or the block specified, just like the regular Ruby <tt>Object#public_send</tt> does.
+ # Invokes the public method whose name goes as first argument just like
+ # +public_send+ does, except that if the receiver does not respond to it the
+ # call returns +nil+ rather than raising an exception.
#
- # *Unlike* that method however, a +NoMethodError+ exception will *not* be raised
- # and +nil+ will be returned instead, if the receiving object is a +nil+ object or NilClass.
+ # This method is defined to be able to write
#
- # This is also true if the receiving object does not implemented the tried method. It will
- # return +nil+ in that case as well.
+ # @person.try(:name)
#
- # If try is called without a method to call, it will yield any given block with the object.
+ # instead of
#
- # Please also note that +try+ is defined on +Object+, therefore it won't work with
- # subclasses of +BasicObject+. For example, using try with +SimpleDelegator+ will
- # delegate +try+ to target instead of calling it on delegator itself.
+ # @person.name if @person
#
- # Without +try+
- # @person && @person.name
- # or
- # @person ? @person.name : nil
+ # +try+ calls can be chained:
#
- # With +try+
- # @person.try(:name)
+ # @person.try(:spouse).try(:name)
+ #
+ # instead of
+ #
+ # @person.spouse.name if @person && @person.spouse
+ #
+ # +try+ will also return +nil+ if the receiver does not respond to the method:
+ #
+ # @person.try(:non_existing_method) # => nil
+ #
+ # instead of
+ #
+ # @person.non_existing_method if @person.respond_to?(:non_existing_method) # => nil
#
- # +try+ also accepts arguments and/or a block, for the method it is trying
- # Person.try(:find, 1)
- # @people.try(:collect) {|p| p.name}
+ # +try+ returns +nil+ when called on +nil+ regardless of whether it responds
+ # to the method:
#
- # Without a method argument try will yield to the block unless the receiver is nil.
- # @person.try { |p| "#{p.first_name} #{p.last_name}" }
+ # nil.try(:to_i) # => nil, rather than 0
#
- # +try+ behaves like +Object#public_send+, unless called on +NilClass+.
+ # Arguments and blocks are forwarded to the method if invoked:
+ #
+ # @posts.try(:each_slice, 2) do |a, b|
+ # ...
+ # end
+ #
+ # The number of arguments in the signature must match. If the object responds
+ # to the method the call is attempted and +ArgumentError+ is still raised
+ # in case of argument mismatch.
+ #
+ # If +try+ is called without arguments it yields the receiver to a given
+ # block unless it is +nil+:
+ #
+ # @person.try do |p|
+ # ...
+ # end
+ #
+ # You can also call try with a block without accepting an argument, and the block
+ # will be instance_eval'ed instead:
+ #
+ # @person.try { upcase.truncate(50) }
+ #
+ # Please also note that +try+ is defined on +Object+. Therefore, it won't work
+ # with instances of classes that do not have +Object+ among their ancestors,
+ # like direct subclasses of +BasicObject+. For example, using +try+ with
+ # +SimpleDelegator+ will delegate +try+ to the target instead of calling it on
+ # the delegator itself.
def try(*a, &b)
- if a.empty? && block_given?
- yield self
- else
- public_send(*a, &b) if respond_to?(a.first)
- end
+ try!(*a, &b) if a.empty? || respond_to?(a.first)
end
- # Same as #try, but will raise a NoMethodError exception if the receiving is not nil and
- # does not implemented the tried method.
+ # Same as #try, but will raise a NoMethodError exception if the receiver is not +nil+ and
+ # does not implement the tried method.
+
def try!(*a, &b)
if a.empty? && block_given?
- yield self
+ if b.arity.zero?
+ instance_eval(&b)
+ else
+ yield self
+ end
else
public_send(*a, &b)
end
@@ -51,12 +81,12 @@ end
class NilClass
# Calling +try+ on +nil+ always returns +nil+.
- # It becomes specially helpful when navigating through associations that may return +nil+.
+ # It becomes especially helpful when navigating through associations that may return +nil+.
#
# nil.try(:name) # => nil
#
# Without +try+
- # @person && !@person.children.blank? && @person.children.first.name
+ # @person && @person.children.any? && @person.children.first.name
#
# With +try+
# @person.try(:children).try(:first).try(:name)
diff --git a/activesupport/lib/active_support/core_ext/object/with_options.rb b/activesupport/lib/active_support/core_ext/object/with_options.rb
index 42e388b065..7d38e1d134 100644
--- a/activesupport/lib/active_support/core_ext/object/with_options.rb
+++ b/activesupport/lib/active_support/core_ext/object/with_options.rb
@@ -34,9 +34,36 @@ class Object
# body i18n.t :body, user_name: user.name
# end
#
+ # When you don't pass an explicit receiver, it executes the whole block
+ # in merging options context:
+ #
+ # class Account < ActiveRecord::Base
+ # with_options dependent: :destroy do
+ # has_many :customers
+ # has_many :products
+ # has_many :invoices
+ # has_many :expenses
+ # end
+ # end
+ #
# <tt>with_options</tt> can also be nested since the call is forwarded to its receiver.
- # Each nesting level will merge inherited defaults in addition to their own.
- def with_options(options)
- yield ActiveSupport::OptionMerger.new(self, options)
+ #
+ # NOTE: Each nesting level will merge inherited defaults in addition to their own.
+ #
+ # class Post < ActiveRecord::Base
+ # with_options if: :persisted?, length: { minimum: 50 } do
+ # validates :content, if: -> { content.present? }
+ # end
+ # end
+ #
+ # The code is equivalent to:
+ #
+ # validates :content, length: { minimum: 50 }, if: -> { content.present? }
+ #
+ # Hence the inherited default for `if` key is ignored.
+ #
+ def with_options(options, &block)
+ option_merger = ActiveSupport::OptionMerger.new(self, options)
+ block.arity.zero? ? option_merger.instance_eval(&block) : block.call(option_merger)
end
end