Same as above, except in Object.
| method_added | -> | blank_slate_method_added |
| __send__ | -> | try |
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/blankslate.rb, line 90
90: def find_hidden_method(name)
91: nil
92: end
Lookup missing generators using const_missing. This allows any generator to reference another without having to know its location: RubyGems, ~/.rails/generators, and RAILS_ROOT/generators.
# File vendor/rails/railties/lib/rails_generator/lookup.rb, line 10
10: def lookup_missing_generator(class_id)
11: if md = /(.+)Generator$/.match(class_id.to_s)
12: name = md.captures.first.demodulize.underscore
13: Rails::Generator::Base.lookup(name).klass
14: else
15: const_missing_before_generators(class_id)
16: end
17: end
Detect method additions to Object and remove them in the BlankSlate class.
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/blankslate.rb, line 83
83: def method_added(name)
84: result = blank_slate_method_added(name)
85: return result if self != Object
86: BlankSlate.hide(name)
87: result
88: end
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.
# File vendor/rails/activesupport/lib/active_support/core_ext/object/misc.rb, line 86
86: def acts_like?(duck)
87: respond_to? "acts_like_#{duck}?"
88: end
# File vendor/rails/activesupport/lib/active_support/json/encoders/object.rb, line 7 7: def as_json(options = nil) 8: instance_values 9: end
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?
# File vendor/rails/activesupport/lib/active_support/core_ext/object/blank.rb, line 12
12: def blank?
13: respond_to?(:empty?) ? empty? : !self
14: end
If class_eval is called on an object, add those methods to its metaclass
# File vendor/rails/activesupport/lib/active_support/core_ext/object/metaclass.rb, line 10
10: def class_eval(*args, &block)
11: metaclass.class_eval(*args, &block)
12: end
Can you safely .dup this object? False for nil, false, true, symbols, and numbers; true otherwise.
# File vendor/rails/activesupport/lib/active_support/core_ext/duplicable.rb, line 4 4: def duplicable? 5: true 6: end
# File vendor/rails/activesupport/lib/active_support/core_ext/string/output_safety.rb, line 68
68: def html_safe?
69: false
70: end
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
# File vendor/rails/activesupport/lib/active_support/core_ext/object/extending.rb, line 63
63: def instance_exec(*args, &block)
64: begin
65: old_critical, Thread.critical = Thread.critical, true
66: n = 0
67: n += 1 while respond_to?(method_name = "__instance_exec#{n}")
68: InstanceExecMethods.module_eval { define_method(method_name, &block) }
69: ensure
70: Thread.critical = old_critical
71: end
72:
73: begin
74: send(method_name, *args)
75: ensure
76: InstanceExecMethods.module_eval { remove_method(method_name) } rescue nil
77: end
78: end
# File vendor/rails/activesupport/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
# File vendor/rails/activesupport/lib/active_support/core_ext/object/instance_variables.rb, line 37
37: def instance_variable_names
38: instance_variables.map { |var| var.to_s }
39: end
Get object‘s meta (ghost, eigenclass, singleton) class
# File vendor/rails/activesupport/lib/active_support/core_ext/object/metaclass.rb, line 3 3: def metaclass 4: class << self 5: self 6: end 7: end
An object is present if it‘s not blank.
# File vendor/rails/activesupport/lib/active_support/core_ext/object/blank.rb, line 17
17: def present?
18: !blank?
19: end
Returns value after yielding value to the block. This simplifies the process of constructing an object, performing work on the object, and then returning the object from a method. It is a Ruby-ized realization of the K combinator, courtesy of Mikael Brockman.
# Without returning
def foo
values = []
values << "bar"
values << "baz"
return values
end
foo # => ['bar', 'baz']
# returning with a local variable
def foo
returning values = [] do
values << 'bar'
values << 'baz'
end
end
foo # => ['bar', 'baz']
# returning with a block argument
def foo
returning [] do |values|
values << 'bar'
values << 'baz'
end
end
foo # => ['bar', 'baz']
# File vendor/rails/activesupport/lib/active_support/core_ext/object/misc.rb, line 38
38: def returning(value)
39: yield(value)
40: value
41: end
Yields x to the block, and then returns x. The primary purpose of this method is to "tap into" a method chain, in order to perform operations on intermediate results within the chain.
(1..10).tap { |x| puts "original: #{x.inspect}" }.to_a.
tap { |x| puts "array: #{x.inspect}" }.
select { |x| x%2 == 0 }.
tap { |x| puts "evens: #{x.inspect}" }.
map { |x| x*x }.
tap { |x| puts "squares: #{x.inspect}" }
# File vendor/rails/activesupport/lib/active_support/core_ext/object/misc.rb, line 53
53: def tap
54: yield self
55: self
56: end
Dumps object in JSON (JavaScript Object Notation). See www.json.org for more info.
# File vendor/rails/activesupport/lib/active_support/json/encoders/object.rb, line 3 3: def to_json(options = nil) 4: ActiveSupport::JSON.encode(as_json(options)) 5: end
# File vendor/rails/actionpack/lib/action_controller/routing/routing_ext.rb, line 2 2: def to_param 3: to_s 4: end
Alias of to_s.
# File vendor/rails/activesupport/lib/active_support/core_ext/object/conversions.rb, line 3 3: def to_param 4: to_s 5: end
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.
# File vendor/rails/activesupport/lib/active_support/core_ext/object/conversions.rb, line 11
11: def to_query(key)
12: require 'cgi' unless defined?(CGI) && defined?(CGI::escape)
13: "#{CGI.escape(key.to_s)}=#{CGI.escape(to_param.to_s)}"
14: end
Invokes the method identified by the symbol method, passing it any arguments and/or the block specified, just like the regular Ruby Object#send does.
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.
Without try
@person && @person.name
or
@person ? @person.name : nil
With try
@person.try(:name)
try also accepts arguments and/or a block, for the method it is trying
Person.try(:find, 1)
@people.try(:collect) {|p| p.name}
# File vendor/rails/activesupport/lib/active_support/core_ext/try.rb, line 25
25: def try(method, *args, &block)
26: send(method, *args, &block)
27: end
An elegant way to factor duplication out of options passed to a series of method calls. Each method called in the block, with the block variable as the receiver, will have its options merged with the default options hash provided. Each method called on the block variable must take an options hash as its final argument.
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
# File vendor/rails/activesupport/lib/active_support/core_ext/object/misc.rb, line 77
77: def with_options(options)
78: yield ActiveSupport::OptionMerger.new(self, options)
79: end