### Home Classes Methods

### In Files

- lib/active_support/whiny_nil.rb
- lib/active_support/core_ext/object/try.rb
- lib/active_support/core_ext/object/blank.rb
- lib/active_support/core_ext/object/duplicable.rb
- lib/active_support/core_ext/object/to_param.rb
- lib/active_support/json/encoding.rb

### Parent

Object

### Methods

- ::add_whiner
- #as_json
- #blank?
- #duplicable?
- #encode_json
- #id
- #to_param
- #try

### Class/Module Index

Quicksearch

- ActiveSupport
- ActiveSupport::Autoload
- ActiveSupport::BacktraceCleaner
- ActiveSupport::Base64
- ActiveSupport::BasicObject
- ActiveSupport::Benchmarkable
- ActiveSupport::BufferedLogger
- ActiveSupport::BufferedLogger::Severity
- ActiveSupport::Cache
- ActiveSupport::Cache::Entry
- ActiveSupport::Cache::FileStore
- ActiveSupport::Cache::MemCacheStore
- ActiveSupport::Cache::MemoryStore
- ActiveSupport::Cache::NullStore
- ActiveSupport::Cache::Store
- ActiveSupport::Cache::Strategy
- ActiveSupport::Cache::Strategy::LocalCache
- ActiveSupport::Cache::Strategy::LocalCache::LocalStore
- ActiveSupport::Callbacks
- ActiveSupport::Callbacks::ClassMethods
- ActiveSupport::Concern
- ActiveSupport::Configurable
- ActiveSupport::Configurable::ClassMethods
- ActiveSupport::Configurable::Configuration
- ActiveSupport::Dependencies
- ActiveSupport::Dependencies::ClassCache
- ActiveSupport::Dependencies::WatchStack
- ActiveSupport::Deprecation
- ActiveSupport::DescendantsTracker
- ActiveSupport::Duration
- ActiveSupport::FileUpdateChecker
- ActiveSupport::FileWatcher
- ActiveSupport::FileWatcher::Backend
- ActiveSupport::Gzip
- ActiveSupport::Gzip::Stream
- ActiveSupport::HashWithIndifferentAccess
- ActiveSupport::HashWithIndifferentAccess
- ActiveSupport::Inflector
- ActiveSupport::Inflector::Inflections
- ActiveSupport::InheritableOptions
- ActiveSupport::JSON
- ActiveSupport::JSON::Encoding
- ActiveSupport::JSON::Encoding::CircularReferenceError
- ActiveSupport::JSON::Encoding::Encoder
- ActiveSupport::JSON::Variable
- ActiveSupport::LogSubscriber
- ActiveSupport::LogSubscriber::TestHelper
- ActiveSupport::LogSubscriber::TestHelper::MockLogger
- ActiveSupport::Memoizable
- ActiveSupport::Memoizable::InstanceMethods
- ActiveSupport::MessageEncryptor
- ActiveSupport::MessageEncryptor::InvalidMessage
- ActiveSupport::MessageVerifier
- ActiveSupport::MessageVerifier::InvalidSignature
- ActiveSupport::Multibyte
- ActiveSupport::Multibyte::Chars
- ActiveSupport::Multibyte::EncodingError
- ActiveSupport::Multibyte::Unicode
- ActiveSupport::Multibyte::Unicode::Codepoint
- ActiveSupport::Multibyte::Unicode::UnicodeDatabase
- ActiveSupport::Notifications
- ActiveSupport::Notifications::Event
- ActiveSupport::Notifications::Fanout
- ActiveSupport::Notifications::Instrumenter
- ActiveSupport::OrderedHash
- ActiveSupport::OrderedOptions
- ActiveSupport::Railtie
- ActiveSupport::Rescuable
- ActiveSupport::Rescuable::ClassMethods
- ActiveSupport::SafeBuffer
- ActiveSupport::SafeBuffer::SafeConcatError
- ActiveSupport::StringInquirer
- ActiveSupport::TaggedLogging
- ActiveSupport::TestCase
- ActiveSupport::Testing
- ActiveSupport::Testing::Assertions
- ActiveSupport::Testing::Declarative
- ActiveSupport::Testing::Isolation
- ActiveSupport::Testing::Isolation::Forking
- ActiveSupport::Testing::Isolation::MiniTest
- ActiveSupport::Testing::Isolation::Subprocess
- ActiveSupport::Testing::Isolation::TestUnit
- ActiveSupport::Testing::Pending
- ActiveSupport::Testing::Performance
- ActiveSupport::Testing::Performance::Benchmarker
- ActiveSupport::Testing::Performance::ForClassicTestUnit
- ActiveSupport::Testing::Performance::ForMiniTest
- ActiveSupport::Testing::Performance::Metrics
- ActiveSupport::Testing::Performance::Metrics::Amount
- ActiveSupport::Testing::Performance::Metrics::Base
- ActiveSupport::Testing::Performance::Metrics::CpuTime
- ActiveSupport::Testing::Performance::Metrics::DigitalInformationUnit
- ActiveSupport::Testing::Performance::Metrics::GcRuns
- ActiveSupport::Testing::Performance::Metrics::GcTime
- ActiveSupport::Testing::Performance::Metrics::Memory
- ActiveSupport::Testing::Performance::Metrics::Objects
- ActiveSupport::Testing::Performance::Metrics::ProcessTime
- ActiveSupport::Testing::Performance::Metrics::Time
- ActiveSupport::Testing::Performance::Metrics::UserTime
- ActiveSupport::Testing::Performance::Metrics::WallTime
- ActiveSupport::Testing::Performance::Performer
- ActiveSupport::Testing::Performance::Profiler
- ActiveSupport::Testing::ProxyTestResult
- ActiveSupport::Testing::RemoteError
- ActiveSupport::Testing::SetupAndTeardown
- ActiveSupport::Testing::SetupAndTeardown::ClassMethods
- ActiveSupport::Testing::SetupAndTeardown::ForClassicTestUnit
- ActiveSupport::Testing::SetupAndTeardown::ForMiniTest
- ActiveSupport::TimeWithZone
- ActiveSupport::TimeZone
- ActiveSupport::XmlMini
- ActiveSupport::XmlMini_LibXMLSAX
- ActiveSupport::XmlMini_LibXMLSAX::HashBuilder
- ActiveSupport::XmlMini_NokogiriSAX
- ActiveSupport::XmlMini_NokogiriSAX::HashBuilder
- Test
- Test::Unit
- Test::Unit::Collector
- Test::Unit::Collector::ObjectSpace
- Object
- Object::HashWithIndifferentAccess
- Object::MissingSourceFile
- ERB
- ERB::Util
- I18n
- I18n::Railtie
- LoadError
- LoadError
- Logger
- Logger::SimpleFormatter
- Array
- Base64
- Benchmark
- BigDecimal
- Class
- Date
- DateTime
- Enumerable
- FalseClass
- File
- Float
- Hash
- Integer
- Kernel
- Module
- NameError
- NilClass
- Numeric
- Process
- QualifiedConstUtils
- Range
- Regexp
- String
- Symbol
- Time
- TrueClass
- URI

No matching classes.

# NilClass

Extensions to `nil` which allow for more helpful error messages for people who are new to Rails.

NilClass#id exists in Ruby 1.8 (though it is deprecated). Since `id` is a fundamental method of Active Record models NilClass#id is redefined as well to raise a RuntimeError and warn the user. She probably wanted a model database identifier and the 4 returned by the original method could result in obscure bugs.

The flag `config.whiny_nils` determines whether this feature is enabled. By default it is on in development and test modes, and it is off in production mode.

### Public Class Methods

add_whiner(klass) click to toggle source

    # File lib/active_support/whiny_nil.rb, line 15
    def self.add_whiner(klass)
      ActiveSupport::Deprecation.warn "NilClass.add_whiner is deprecated and this functionality is "        "removed from Rails versions as it affects Ruby 1.9 performance.", caller
    end

### Public Instance Methods

as_json(options = nil) click to toggle source

    # File lib/active_support/json/encoding.rb, line 171
    def as_json(options = nil) self end

blank?() click to toggle source

`nil` is blank:

    nil.blank? # => true

    # File lib/active_support/core_ext/object/blank.rb, line 47
    def blank?
      true
    end

duplicable?() click to toggle source

`nil` is not duplicable:

    nil.duplicable? # => false
    nil.dup         # => TypeError: can't dup NilClass

    # File lib/active_support/core_ext/object/duplicable.rb, line 35
    def duplicable?
      false
    end

encode_json(encoder) click to toggle source

    # File lib/active_support/json/encoding.rb, line 172
    def encode_json(encoder) 'null' end

id() click to toggle source

Raises a RuntimeError when you attempt to call `id` on `nil`.

    # File lib/active_support/whiny_nil.rb, line 21
    def id
      raise RuntimeError, "Called id for nil, which would mistakenly be #{object_id} -- if you really wanted the id of nil, use object_id", caller
    end

to_param() click to toggle source

    # File lib/active_support/core_ext/object/to_param.rb, line 9
    def to_param
      self
    end

try(*args) click to toggle source

Calling `try` on `nil` always returns `nil`. It becomes specially helpful when navigating through associations that may return `nil`.

### Examples

    nil.try(:name) # => nil

Without `try`

    @person && !@person.children.blank? && @person.children.first.name

With `try`

    @person.try(:children).try(:first).try(:name)

    # File lib/active_support/core_ext/object/try.rb, line 54
    def try(*args)
      nil
    end

[Validate]

Generated with the Darkfish Rdoc Generator 2.