# Table of Contents - activemodel-4.2.4 Documentation

## Classes and Modules

- ActiveModel
- ActiveModel::AttributeMethods
  - Active Model Attribute Methods
- ActiveModel::AttributeMethods::ClassMethods
- ActiveModel::AttributeMethods::ClassMethods::AttributeMethodMatcher
- ActiveModel::BlockValidator
- ActiveModel::Callbacks
  - Active Model Callbacks
- ActiveModel::Conversion
  - Active Model Conversion
- ActiveModel::Conversion::ClassMethods
- ActiveModel::Dirty
  - Active Model Dirty
- ActiveModel::EachValidator
- ActiveModel::Errors
  - Active Model Errors
- ActiveModel::ForbiddenAttributesError
- ActiveModel::ForbiddenAttributesProtection
- ActiveModel::Lint
- ActiveModel::Lint::Tests
  - Active Model Lint Tests
- ActiveModel::MissingAttributeError
- ActiveModel::Model
  - Active Model Basic Model
- ActiveModel::Name
- ActiveModel::Naming
  - Active Model Naming
- ActiveModel::Railtie
- ActiveModel::SecurePassword
- ActiveModel::SecurePassword::ClassMethods
- ActiveModel::SecurePassword::InstanceMethodsOnActivation
- ActiveModel::Serialization
  - Active Model Serialization
- ActiveModel::Serializers
- ActiveModel::Serializers::JSON
  - Active Model JSON Serializer
- ActiveModel::Serializers::Xml
  - Active Model XML Serializer
- ActiveModel::Serializers::Xml::Serializer
- ActiveModel::Serializers::Xml::Serializer::Attribute
- ActiveModel::Serializers::Xml::Serializer::MethodAttribute
- ActiveModel::StrictValidationFailed
- ActiveModel::TestCase
- ActiveModel::Translation
  - Active Model Translation
- ActiveModel::VERSION
- ActiveModel::Validations
  - Active Model Validations
  - Active Model Length Validator
- ActiveModel::Validations::AbsenceValidator
- ActiveModel::Validations::AcceptanceValidator
- ActiveModel::Validations::Callbacks
  - Active Model Validation Callbacks
- ActiveModel::Validations::Callbacks::ClassMethods
- ActiveModel::Validations::ClassMethods
- ActiveModel::Validations::Clusivity
- ActiveModel::Validations::ConfirmationValidator
- ActiveModel::Validations::ExclusionValidator
- ActiveModel::Validations::FormatValidator
- ActiveModel::Validations::HelperMethods
- ActiveModel::Validations::InclusionValidator
- ActiveModel::Validations::LengthValidator
- ActiveModel::Validations::NumericalityValidator
- ActiveModel::Validations::PresenceValidator
- ActiveModel::Validations::WithValidator
- ActiveModel::Validator
  - Active Model Validator

## Methods

- ::eager_load! — ActiveModel
- ::gem_version — ActiveModel
- ::kind — ActiveModel::Validator
- ::new — ActiveModel::Errors
- ::new — ActiveModel::Name
- ::new — ActiveModel::Model
- ::new — ActiveModel::Validator
- ::param_key — ActiveModel::Naming
- ::plural — ActiveModel::Naming
- ::route_key — ActiveModel::Naming
- ::singular — ActiveModel::Naming
- ::singular_route_key — ActiveModel::Naming
- ::uncountable? — ActiveModel::Naming
- ::version — ActiveModel
- #!~ — ActiveModel::Name
- #<=> — ActiveModel::Name
- #== — ActiveModel::Name
- #=== — ActiveModel::Name
- #=~ — ActiveModel::Name
- #[] — ActiveModel::Errors
- #[]= — ActiveModel::Errors
- #_merge_attributes — ActiveModel::Validations::HelperMethods
- #_singularize — ActiveModel::Name
- #add — ActiveModel::Errors
- #add_on_blank — ActiveModel::Errors
- #add_on_empty — ActiveModel::Errors
- #added? — ActiveModel::Errors
- #after_validation — ActiveModel::Validations::Callbacks::ClassMethods
- #alias_attribute — ActiveModel::AttributeMethods::ClassMethods
- #as_json — ActiveModel::Serializers::JSON
- #as_json — ActiveModel::Errors
- #assert_boolean — ActiveModel::Lint::Tests
- #attribute_alias — ActiveModel::AttributeMethods::ClassMethods
- #attribute_alias? — ActiveModel::AttributeMethods::ClassMethods
- #attribute_change — ActiveModel::Dirty
- #attribute_changed_by_setter? — ActiveModel::Dirty
- #attribute_method? — ActiveModel::Validations::ClassMethods
- #attribute_method_affix — ActiveModel::AttributeMethods::ClassMethods
- #attribute_method_prefix — ActiveModel::AttributeMethods::ClassMethods
- #attribute_method_suffix — ActiveModel::AttributeMethods::ClassMethods
- #attribute_missing — ActiveModel::AttributeMethods
- #attribute_will_change! — ActiveModel::Dirty
- #attributes_changed_by_setter — ActiveModel::Dirty
- #authenticate — ActiveModel::SecurePassword::InstanceMethodsOnActivation
- #before_validation — ActiveModel::Validations::Callbacks::ClassMethods
- #blank? — ActiveModel::Errors
- #changed — ActiveModel::Dirty
- #changed? — ActiveModel::Dirty
- #changed_attributes — ActiveModel::Dirty
- #changes — ActiveModel::Dirty
- #changes_applied — ActiveModel::Dirty
- #changes_include? — ActiveModel::Dirty
- #clear — ActiveModel::Errors
- #clear_attribute_changes — ActiveModel::Dirty
- #clear_changes_information — ActiveModel::Dirty
- #clear_validators! — ActiveModel::Validations::ClassMethods
- #count — ActiveModel::Errors
- #define_attribute_method — ActiveModel::AttributeMethods::ClassMethods
- #define_attribute_methods — ActiveModel::AttributeMethods::ClassMethods
- #define_model_callbacks — ActiveModel::Callbacks
- #delete — ActiveModel::Errors
- #each — ActiveModel::Errors
- #empty? — ActiveModel::Errors
- #eql? — ActiveModel::Name
- #errors — ActiveModel::Validations
- #from_json — ActiveModel::Serializers::JSON
- #from_xml — ActiveModel::Serializers::Xml
- #full_message — ActiveModel::Errors
- #full_messages — ActiveModel::Errors
- #full_messages_for — ActiveModel::Errors
- #generate_message — ActiveModel::Errors
- #get — ActiveModel::Errors
- #has_key? — ActiveModel::Errors
- #has_secure_password — ActiveModel::SecurePassword::ClassMethods
- #human — ActiveModel::Name
- #human_attribute_name — ActiveModel::Translation
- #i18n_scope — ActiveModel::Translation
- #include? — ActiveModel::Errors
- #invalid? — ActiveModel::Validations
- #key? — ActiveModel::Errors
- #keys — ActiveModel::Errors
- #kind — ActiveModel::Validator
- #lookup_ancestors — ActiveModel::Translation
- #match_attribute_method? — ActiveModel::AttributeMethods
- #method_missing — ActiveModel::AttributeMethods
- #missing_attribute — ActiveModel::AttributeMethods
- #model — ActiveModel::Lint::Tests
- #model_name — ActiveModel::Naming
- #normalize_message — ActiveModel::Errors
- #password= — ActiveModel::SecurePassword::InstanceMethodsOnActivation
- #password_confirmation= — ActiveModel::SecurePassword::InstanceMethodsOnActivation
- #persisted? — ActiveModel::Model
- #previous_changes — ActiveModel::Dirty
- #reset_attribute! — ActiveModel::Dirty
- #reset_changes — ActiveModel::Dirty
- #respond_to? — ActiveModel::AttributeMethods
- #respond_to_without_attributes? — ActiveModel::AttributeMethods
- #restore_attribute! — ActiveModel::Dirty
- #restore_attributes — ActiveModel::Dirty
- #serializable_hash — ActiveModel::Serialization
- #set — ActiveModel::Errors
- #set_attribute_was — ActiveModel::Dirty
- #size — ActiveModel::Errors
- #test_errors_aref — ActiveModel::Lint::Tests
- #test_model_naming — ActiveModel::Lint::Tests
- #test_persisted? — ActiveModel::Lint::Tests
- #test_to_key — ActiveModel::Lint::Tests
- #test_to_param — ActiveModel::Lint::Tests
- #test_to_partial_path — ActiveModel::Lint::Tests
- #to_a — ActiveModel::Errors
- #to_hash — ActiveModel::Errors
- #to_key — ActiveModel::Conversion
- #to_model — ActiveModel::Conversion
- #to_param — ActiveModel::Conversion
- #to_partial_path — ActiveModel::Conversion
- #to_s — ActiveModel::Name
- #to_str — ActiveModel::Name
- #to_xml — ActiveModel::Errors
- #to_xml — ActiveModel::Serializers::Xml
- #undefine_attribute_methods — ActiveModel::AttributeMethods::ClassMethods
- #valid? — ActiveModel::Validations
- #validate — ActiveModel::Validations::ClassMethods
- #validate — ActiveModel::Validator
- #validate — ActiveModel::Validations
- #validates — ActiveModel::Validations::ClassMethods
- #validates! — ActiveModel::Validations::ClassMethods
- #validates_absence_of — ActiveModel::Validations::HelperMethods
- #validates_acceptance_of — ActiveModel::Validations::HelperMethods
- #validates_confirmation_of — ActiveModel::Validations::HelperMethods
- #validates_each — ActiveModel::Validations::ClassMethods
- #validates_exclusion_of — ActiveModel::Validations::HelperMethods
- #validates_format_of — ActiveModel::Validations::HelperMethods
- #validates_inclusion_of — ActiveModel::Validations::HelperMethods
- #validates_length_of — ActiveModel::Validations::HelperMethods
- #validates_numericality_of — ActiveModel::Validations::HelperMethods
- #validates_presence_of — ActiveModel::Validations::HelperMethods
- #validates_size_of — ActiveModel::Validations::HelperMethods
- #validates_with — ActiveModel::Validations
- #validates_with — ActiveModel::Validations::ClassMethods
- #validators — ActiveModel::Validations::ClassMethods
- #validators_on — ActiveModel::Validations::ClassMethods
- #values — ActiveModel::Errors