activemodel/lib/active_model/errors.rb
# frozen_string_literal: true
require "active_support/core_ext/array/conversions"
require "active_support/core_ext/string/inflections"
require "active_support/core_ext/object/deep_dup"
require "active_model/error"
require "active_model/nested_error"
require "forwardable"
module ActiveModel
# = Active \Model \Errors
#
# Provides error related functionalities you can include in your object
# for handling error messages and interacting with Action View helpers.
#
# A minimal implementation could be:
#
# class Person
# # Required dependency for ActiveModel::Errors
# extend ActiveModel::Naming
#
# def initialize
# @errors = ActiveModel::Errors.new(self)
# end
#
# attr_accessor :name
# attr_reader :errors
#
# def validate!
# errors.add(:name, :blank, message: "cannot be nil") if name.nil?
# end
#
# # The following methods are needed to be minimally implemented
#
# def read_attribute_for_validation(attr)
# send(attr)
# end
#
# def self.human_attribute_name(attr, options = {})
# attr
# end
#
# def self.lookup_ancestors
# [self]
# end
# end
#
# The last three methods are required in your object for +Errors+ to be
# able to generate error messages correctly and also handle multiple
# languages. Of course, if you extend your object with ActiveModel::Translation
# you will not need to implement the last two. Likewise, using
# ActiveModel::Validations will handle the validation related methods
# for you.
#
# The above allows you to do:
#
# person = Person.new
# person.validate! # => ["cannot be nil"]
# person.errors.full_messages # => ["name cannot be nil"]
# # etc..
class Errors
include Enumerable
extend Forwardable
##
# :method: each
#
# :call-seq: each(&block)
#
# Iterates through each error object.
#
# person.errors.add(:name, :too_short, count: 2)
# person.errors.each do |error|
# # Will yield <#ActiveModel::Error attribute=name, type=too_short,
# options={:count=>3}>
# end
##
# :method: clear
#
# :call-seq: clear
#
# Clears all errors. Clearing the errors does not, however, make the model
# valid. The next time the validations are run (for example, via
# ActiveRecord::Validations#valid?), the errors collection will be filled
# again if any validations fail.
##
# :method: empty?
#
# :call-seq: empty?
#
# Returns true if there are no errors.
##
# :method: size
#
# :call-seq: size
#
# Returns number of errors.
def_delegators :@errors, :each, :clear, :empty?, :size, :uniq!
# The actual array of +Error+ objects
# This method is aliased to <tt>objects</tt>.
attr_reader :errors
alias :objects :errors
# Pass in the instance of the object that is using the errors object.
#
# class Person
# def initialize
# @errors = ActiveModel::Errors.new(self)
# end
# end
def initialize(base)
@base = base
@errors = []
end
def initialize_dup(other) # :nodoc:
@errors = other.errors.deep_dup
super
end
# Copies the errors from <tt>other</tt>.
# For copying errors but keep <tt>@base</tt> as is.
#
# ==== Parameters
#
# * +other+ - The ActiveModel::Errors instance.
#
# ==== Examples
#
# person.errors.copy!(other)
#
def copy!(other) # :nodoc:
@errors = other.errors.deep_dup
@errors.each { |error|
error.instance_variable_set(:@base, @base)
}
end
# Imports one error.
# Imported errors are wrapped as a NestedError,
# providing access to original error object.
# If attribute or type needs to be overridden, use +override_options+.
#
# ==== Options
#
# * +:attribute+ - Override the attribute the error belongs to.
# * +:type+ - Override type of the error.
def import(error, override_options = {})
[:attribute, :type].each do |key|
if override_options.key?(key)
override_options[key] = override_options[key].to_sym
end
end
@errors.append(NestedError.new(@base, error, override_options))
end
# Merges the errors from <tt>other</tt>,
# each Error wrapped as NestedError.
#
# ==== Parameters
#
# * +other+ - The ActiveModel::Errors instance.
#
# ==== Examples
#
# person.errors.merge!(other)
#
def merge!(other)
return errors if equal?(other)
other.errors.each { |error|
import(error)
}
end
# Search for errors matching +attribute+, +type+, or +options+.
#
# Only supplied params will be matched.
#
# person.errors.where(:name) # => all name errors.
# person.errors.where(:name, :too_short) # => all name errors being too short
# person.errors.where(:name, :too_short, minimum: 2) # => all name errors being too short and minimum is 2
def where(attribute, type = nil, **options)
attribute, type, options = normalize_arguments(attribute, type, **options)
@errors.select { |error|
error.match?(attribute, type, **options)
}
end
# Returns +true+ if the error messages include an error for the given key
# +attribute+, +false+ otherwise.
#
# person.errors.messages # => {:name=>["cannot be nil"]}
# person.errors.include?(:name) # => true
# person.errors.include?(:age) # => false
def include?(attribute)
@errors.any? { |error|
error.match?(attribute.to_sym)
}
end
alias :has_key? :include?
alias :key? :include?
# Delete messages for +key+. Returns the deleted messages.
#
# person.errors[:name] # => ["cannot be nil"]
# person.errors.delete(:name) # => ["cannot be nil"]
# person.errors[:name] # => []
def delete(attribute, type = nil, **options)
attribute, type, options = normalize_arguments(attribute, type, **options)
matches = where(attribute, type, **options)
matches.each do |error|
@errors.delete(error)
end
matches.map(&:message).presence
end
# When passed a symbol or a name of a method, returns an array of errors
# for the method.
#
# person.errors[:name] # => ["cannot be nil"]
# person.errors['name'] # => ["cannot be nil"]
def [](attribute)
messages_for(attribute)
end
# Returns all error attribute names
#
# person.errors.messages # => {:name=>["cannot be nil", "must be specified"]}
# person.errors.attribute_names # => [:name]
def attribute_names
@errors.map(&:attribute).uniq.freeze
end
# Returns a Hash that can be used as the JSON representation for this
# object. You can pass the <tt>:full_messages</tt> option. This determines
# if the JSON object should contain full messages or not (false by default).
#
# person.errors.as_json # => {:name=>["cannot be nil"]}
# person.errors.as_json(full_messages: true) # => {:name=>["name cannot be nil"]}
def as_json(options = nil)
to_hash(options && options[:full_messages])
end
# Returns a Hash of attributes with their error messages. If +full_messages+
# is +true+, it will contain full messages (see +full_message+).
#
# person.errors.to_hash # => {:name=>["cannot be nil"]}
# person.errors.to_hash(true) # => {:name=>["name cannot be nil"]}
def to_hash(full_messages = false)
message_method = full_messages ? :full_message : :message
group_by_attribute.transform_values do |errors|
errors.map(&message_method)
end
end
undef :to_h
EMPTY_ARRAY = [].freeze # :nodoc:
# Returns a Hash of attributes with an array of their error messages.
def messages
hash = to_hash
hash.default = EMPTY_ARRAY
hash.freeze
hash
end
# Returns a Hash of attributes with an array of their error details.
def details
hash = group_by_attribute.transform_values do |errors|
errors.map(&:details)
end
hash.default = EMPTY_ARRAY
hash.freeze
hash
end
# Returns a Hash of attributes with an array of their Error objects.
#
# person.errors.group_by_attribute
# # => {:name=>[<#ActiveModel::Error>, <#ActiveModel::Error>]}
def group_by_attribute
@errors.group_by(&:attribute)
end
# Adds a new error of +type+ on +attribute+.
# More than one error can be added to the same +attribute+.
# If no +type+ is supplied, <tt>:invalid</tt> is assumed.
#
# person.errors.add(:name)
# # Adds <#ActiveModel::Error attribute=name, type=invalid>
# person.errors.add(:name, :not_implemented, message: "must be implemented")
# # Adds <#ActiveModel::Error attribute=name, type=not_implemented,
# options={:message=>"must be implemented"}>
#
# person.errors.messages
# # => {:name=>["is invalid", "must be implemented"]}
#
# If +type+ is a string, it will be used as error message.
#
# If +type+ is a symbol, it will be translated using the appropriate
# scope (see +generate_message+).
#
# person.errors.add(:name, :blank)
# person.errors.messages
# # => {:name=>["can't be blank"]}
#
# person.errors.add(:name, :too_long, count: 25)
# person.errors.messages
# # => ["is too long (maximum is 25 characters)"]
#
# If +type+ is a proc, it will be called, allowing for things like
# <tt>Time.now</tt> to be used within an error.
#
# If the <tt>:strict</tt> option is set to +true+, it will raise
# ActiveModel::StrictValidationFailed instead of adding the error.
# <tt>:strict</tt> option can also be set to any other exception.
#
# person.errors.add(:name, :invalid, strict: true)
# # => ActiveModel::StrictValidationFailed: Name is invalid
# person.errors.add(:name, :invalid, strict: NameIsInvalid)
# # => NameIsInvalid: Name is invalid
#
# person.errors.messages # => {}
#
# +attribute+ should be set to <tt>:base</tt> if the error is not
# directly associated with a single attribute.
#
# person.errors.add(:base, :name_or_email_blank,
# message: "either name or email must be present")
# person.errors.messages
# # => {:base=>["either name or email must be present"]}
# person.errors.details
# # => {:base=>[{error: :name_or_email_blank}]}
def add(attribute, type = :invalid, **options)
attribute, type, options = normalize_arguments(attribute, type, **options)
error = Error.new(@base, attribute, type, **options)
if exception = options[:strict]
exception = ActiveModel::StrictValidationFailed if exception == true
raise exception, error.full_message
end
@errors.append(error)
error
end
# Returns +true+ if an error matches provided +attribute+ and +type+,
# or +false+ otherwise. +type+ is treated the same as for +add+.
#
# person.errors.add :name, :blank
# person.errors.added? :name, :blank # => true
# person.errors.added? :name, "can't be blank" # => true
#
# If the error requires options, then it returns +true+ with
# the correct options, or +false+ with incorrect or missing options.
#
# person.errors.add :name, :too_long, count: 25
# person.errors.added? :name, :too_long, count: 25 # => true
# person.errors.added? :name, "is too long (maximum is 25 characters)" # => true
# person.errors.added? :name, :too_long, count: 24 # => false
# person.errors.added? :name, :too_long # => false
# person.errors.added? :name, "is too long" # => false
def added?(attribute, type = :invalid, options = {})
attribute, type, options = normalize_arguments(attribute, type, **options)
if type.is_a? Symbol
@errors.any? { |error|
error.strict_match?(attribute, type, **options)
}
else
messages_for(attribute).include?(type)
end
end
# Returns +true+ if an error on the attribute with the given type is
# present, or +false+ otherwise. +type+ is treated the same as for +add+.
#
# person.errors.add :age
# person.errors.add :name, :too_long, count: 25
# person.errors.of_kind? :age # => true
# person.errors.of_kind? :name # => false
# person.errors.of_kind? :name, :too_long # => true
# person.errors.of_kind? :name, "is too long (maximum is 25 characters)" # => true
# person.errors.of_kind? :name, :not_too_long # => false
# person.errors.of_kind? :name, "is too long" # => false
def of_kind?(attribute, type = :invalid)
attribute, type = normalize_arguments(attribute, type)
if type.is_a? Symbol
!where(attribute, type).empty?
else
messages_for(attribute).include?(type)
end
end
# Returns all the full error messages in an array.
#
# class Person
# validates_presence_of :name, :address, :email
# validates_length_of :name, in: 5..30
# end
#
# person = Person.create(address: '123 First St.')
# person.errors.full_messages
# # => ["Name is too short (minimum is 5 characters)", "Name can't be blank", "Email can't be blank"]
def full_messages
@errors.map(&:full_message)
end
alias :to_a :full_messages
# Returns all the full error messages for a given attribute in an array.
#
# class Person
# validates_presence_of :name, :email
# validates_length_of :name, in: 5..30
# end
#
# person = Person.create()
# person.errors.full_messages_for(:name)
# # => ["Name is too short (minimum is 5 characters)", "Name can't be blank"]
def full_messages_for(attribute)
where(attribute).map(&:full_message).freeze
end
# Returns all the error messages for a given attribute in an array.
#
# class Person
# validates_presence_of :name, :email
# validates_length_of :name, in: 5..30
# end
#
# person = Person.create()
# person.errors.messages_for(:name)
# # => ["is too short (minimum is 5 characters)", "can't be blank"]
def messages_for(attribute)
where(attribute).map(&:message)
end
# Returns a full message for a given attribute.
#
# person.errors.full_message(:name, 'is invalid') # => "Name is invalid"
def full_message(attribute, message)
Error.full_message(attribute, message, @base)
end
# Translates an error message in its default scope
# (<tt>activemodel.errors.messages</tt>).
#
# Error messages are first looked up in <tt>activemodel.errors.models.MODEL.attributes.ATTRIBUTE.MESSAGE</tt>,
# if it's not there, it's looked up in <tt>activemodel.errors.models.MODEL.MESSAGE</tt> and if
# that is not there also, it returns the translation of the default message
# (e.g. <tt>activemodel.errors.messages.MESSAGE</tt>). The translated model
# name, translated attribute name, and the value are available for
# interpolation.
#
# When using inheritance in your models, it will check all the inherited
# models too, but only if the model itself hasn't been found. Say you have
# <tt>class Admin < User; end</tt> and you wanted the translation for
# the <tt>:blank</tt> error message for the <tt>title</tt> attribute,
# it looks for these translations:
#
# * <tt>activemodel.errors.models.admin.attributes.title.blank</tt>
# * <tt>activemodel.errors.models.admin.blank</tt>
# * <tt>activemodel.errors.models.user.attributes.title.blank</tt>
# * <tt>activemodel.errors.models.user.blank</tt>
# * any default you provided through the +options+ hash (in the <tt>activemodel.errors</tt> scope)
# * <tt>activemodel.errors.messages.blank</tt>
# * <tt>errors.attributes.title.blank</tt>
# * <tt>errors.messages.blank</tt>
def generate_message(attribute, type = :invalid, options = {})
Error.generate_message(attribute, type, @base, options)
end
def inspect # :nodoc:
inspection = @errors.inspect
"#<#{self.class.name} #{inspection}>"
end
private
def normalize_arguments(attribute, type, **options)
# Evaluate proc first
if type.respond_to?(:call)
type = type.call(@base, options)
end
[attribute.to_sym, type, options]
end
end
# = Active \Model \StrictValidationFailed
#
# Raised when a validation cannot be corrected by end users and are considered
# exceptional.
#
# class Person
# include ActiveModel::Validations
#
# attr_accessor :name
#
# validates_presence_of :name, strict: true
# end
#
# person = Person.new
# person.name = nil
# person.valid?
# # => ActiveModel::StrictValidationFailed: Name can't be blank
class StrictValidationFailed < StandardError
end
# = Active \Model \RangeError
#
# Raised when attribute values are out of range.
class RangeError < ::RangeError
end
# = Active \Model \UnknownAttributeError
#
# Raised when unknown attributes are supplied via mass assignment.
#
# class Person
# include ActiveModel::AttributeAssignment
# include ActiveModel::Validations
# end
#
# person = Person.new
# person.assign_attributes(name: 'Gorby')
# # => ActiveModel::UnknownAttributeError: unknown attribute 'name' for Person.
class UnknownAttributeError < NoMethodError
attr_reader :record, :attribute
def initialize(record, attribute)
@record = record
@attribute = attribute
super("unknown attribute '#{attribute}' for #{@record.class}.")
end
end
end