Methods
Included Modules
Public Instance methods
acts_like?(duck)

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.

[ show source ]

    # File lib/active_support/core_ext/object/misc.rb, line 56
56:   def acts_like?(duck)
57:     respond_to? "acts_like_#{duck}?"
58:   end
blank?()

An object is blank if it‘s false, empty, or a whitespace string. For example, "", " ", nil, [], and {} are blank.

This simplifies 

  if !address.nil? && !address.empty?

to 

  if !address.blank?

[ show source ]

    # File lib/active_support/core_ext/blank.rb, line 12
12:   def blank?
13:     respond_to?(:empty?) ? empty? : !self
14:   end
duplicable?()

Can you safely .dup this object? False for nil, false, true, symbols, and numbers; true otherwise.

[ show source ]

   # File lib/active_support/core_ext/duplicable.rb, line 4
4:   def duplicable?
5:     true
6:   end
instance_exec(*args, &block)

Evaluate the block with the given arguments within the context of this object, so self is set to the method receiver.

From Mauricio‘s eigenclass.org/hiki/bounded+space+instance_exec

[ show source ]

    # File lib/active_support/core_ext/object/extending.rb, line 42
42:     def instance_exec(*args, &block)
43:       begin
44:         old_critical, Thread.critical = Thread.critical, true
45:         n = 0
46:         n += 1 while respond_to?(method_name = "__instance_exec#{n}")
47:         InstanceExecMethods.module_eval { define_method(method_name, &block) }
48:       ensure
49:         Thread.critical = old_critical
50:       end
51: 
52:       begin
53:         send(method_name, *args)
54:       ensure
55:         InstanceExecMethods.module_eval { remove_method(method_name) } rescue nil
56:       end
57:     end
instance_variable_defined?(variable)

[ show source ]

   # File lib/active_support/core_ext/object/instance_variables.rb, line 4
4:     def instance_variable_defined?(variable)
5:       instance_variables.include?(variable.to_s)
6:     end
instance_variable_names()

[ show source ]

    # File lib/active_support/core_ext/object/instance_variables.rb, line 37
37:     def instance_variable_names
38:       instance_variables.map(&:to_s)
39:     end
returning(value) {|value| ...}

A Ruby-ized realization of the K combinator, courtesy of Mikael Brockman. 

  def foo
    returning values = [] do
      values << 'bar'
      values << 'baz'
    end
  end

  foo # => ['bar', 'baz']

  def foo
    returning [] do |values|
      values << 'bar'
      values << 'baz'
    end
  end

  foo # => ['bar', 'baz']

[ show source ]

    # File lib/active_support/core_ext/object/misc.rb, line 27
27:   def returning(value)
28:     yield(value)
29:     value
30:   end
to_json(options = {})

Dumps object in JSON (JavaScript Object Notation). See www.json.org for more info.

[ show source ]

   # File lib/active_support/json/encoders/object.rb, line 3
3:   def to_json(options = {})
4:     ActiveSupport::JSON.encode(instance_values, options)
5:   end
to_param()

Alias of to_s.

[ show source ]

   # File lib/active_support/core_ext/object/conversions.rb, line 3
3:   def to_param
4:     to_s
5:   end
to_query(key)

Converts an object into a string suitable for use as a URL query string, using the given key as the param name.

Note: This method is defined as a default implementation for all Objects for Hash#to_query to work.

[ show source ]

    # File lib/active_support/core_ext/object/conversions.rb, line 11
11:   def to_query(key)
12:     "#{CGI.escape(key.to_s)}=#{CGI.escape(to_param.to_s)}"
13:   end
unloadable(const_desc)

Mark the given constant as unloadable. Unloadable constants are removed each time dependencies are cleared.

Note that marking a constant for unloading need only be done once. Setup or init scripts may list each unloadable constant that may need unloading; each constant will be removed for every subsequent clear, as opposed to for the first clear.

The provided constant descriptor may be a (non-anonymous) module or class, or a qualified constant name as a string or symbol.

Returns true if the constant was not previously marked for unloading, false otherwise.

[ show source ]

     # File lib/active_support/dependencies.rb, line 529
529:   def unloadable(const_desc)
530:     ActiveSupport::Dependencies.mark_for_unload const_desc
531:   end
with_options(options) {|ActiveSupport::OptionMerger.new(self, options)| ...}

An elegant way to refactor out common options 

  with_options :order => 'created_at', :class_name => 'Comment' do |post|
    post.has_many :comments, :conditions => ['approved = ?', true], :dependent => :delete_all
    post.has_many :unapproved_comments, :conditions => ['approved = ?', false]
    post.has_many :all_comments
  end

Can also be used with an explicit receiver: 

  map.with_options :controller => "people" do |people|
    people.connect "/people",     :action => "index"
    people.connect "/people/:id", :action => "show"
  end

[ show source ]

    # File lib/active_support/core_ext/object/misc.rb, line 47
47:   def with_options(options)
48:     yield ActiveSupport::OptionMerger.new(self, options)
49:   end