ActiveModel::Errors (original) (raw)

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..

Methods

• []

A

• add,
• added?,
• as_json,
• attribute_names

C

• clear

D

• delete,
• details

E

• each,
• empty?

F

• full_message,
• full_messages,
• full_messages_for

G

• generate_message,
• group_by_attribute

H

• has_key?

I

• import,
• include?

K

• key?

M

• merge!,
• messages,
• messages_for

N

• new

O

• of_kind?

S

• size

T

• to_a,
• to_hash

W

• where

Included Modules

• Enumerable

Attributes

Class Public methods

new(base)Link

Pass in the instance of the object that is using the errors object.

class Person
  def initialize
    @errors = ActiveModel::Errors.new(self)
  end
end

Source: show | on GitHub

def initialize(base) @base = base @errors = [] end

Instance Public methods

[](attribute)Link

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"]

Source: show | on GitHub

def messages_for(attribute) end

add(attribute, type = :invalid, **options)Link

Adds a new error of type on attribute. More than one error can be added to the same attribute. If no type is supplied, :invalid 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 Time.now to be used within an error.

If the :strict option is set to true, it will raise ActiveModel::StrictValidationFailed instead of adding the error. :strict 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 :base 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}]}

Source: show | on GitHub

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

added?(attribute, type = :invalid, options = {})Link

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

Source: show | on GitHub

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

as_json(options = nil)Link

Returns a Hash that can be used as the JSON representation for this object. You can pass the :full_messages 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"]}

Source: show | on GitHub

def as_json(options = nil) to_hash(options && options[:full_messages]) end

attribute_names()Link

Returns all error attribute names

person.errors.messages        # => {:name=>["cannot be nil", "must be specified"]}
person.errors.attribute_names # => [:name]

Source: show | on GitHub

def attribute_names @errors.map(&:attribute).uniq.freeze end

clear Link

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.

delete(attribute, type = nil, **options)Link

Delete messages for key. Returns the deleted messages.

person.errors[:name]        # => ["cannot be nil"]
person.errors.delete(:name) # => ["cannot be nil"]
person.errors[:name]        # => []

Source: show | on GitHub

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

details()Link

Returns a Hash of attributes with an array of their error details.

Source: show | on GitHub

def details hash = group_by_attribute.transform_values do |errors| errors.map(&:details) end hash.default = EMPTY_ARRAY hash.freeze hash end

each(&block) Link

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

empty? Link

Returns true if there are no errors.

full_message(attribute, message)Link

Returns a full message for a given attribute.

person.errors.full_message(:name, 'is invalid') # => "Name is invalid"

Source: show | on GitHub

def full_message(attribute, message) Error.full_message(attribute, message, @base) end

full_messages()Link

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"]

Also aliased as: to_a

Source: show | on GitHub

def full_messages @errors.map(&:full_message) end

full_messages_for(attribute)Link

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"]

Source: show | on GitHub

def full_messages_for(attribute) where(attribute).map(&:full_message).freeze end

generate_message(attribute, type = :invalid, options = {})Link

Translates an error message in its default scope (activemodel.errors.messages).

Error messages are first looked up in activemodel.errors.models.MODEL.attributes.ATTRIBUTE.MESSAGE, if it’s not there, it’s looked up in activemodel.errors.models.MODEL.MESSAGE and if that is not there also, it returns the translation of the default message (e.g. activemodel.errors.messages.MESSAGE). 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 class Admin < User; end and you wanted the translation for the :blank error message for the title attribute, it looks for these translations:

• activemodel.errors.models.admin.attributes.title.blank
• activemodel.errors.models.admin.blank
• activemodel.errors.models.user.attributes.title.blank
• activemodel.errors.models.user.blank
• any default you provided through the options hash (in the activemodel.errors scope)
• activemodel.errors.messages.blank
• errors.attributes.title.blank
• errors.messages.blank

Source: show | on GitHub

def generate_message(attribute, type = :invalid, options = {}) Error.generate_message(attribute, type, @base, options) end

group_by_attribute()Link

Returns a Hash of attributes with an array of their Error objects.

person.errors.group_by_attribute
# => {:name=>[<#ActiveModel::Error>, <#ActiveModel::Error>]}

Source: show | on GitHub

def group_by_attribute @errors.group_by(&:attribute) end

has_key?(attribute)Link

import(error, override_options = {})Link

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.

Source: show | on GitHub

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

include?(attribute)Link

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

Source: show | on GitHub

def include?(attribute) @errors.any? { |error| error.match?(attribute.to_sym) } end

key?(attribute)Link

merge!(other)Link

Source: show | on GitHub

def merge!(other) return errors if equal?(other)

other.errors.each { |error| import(error) } end

messages()Link

Returns a Hash of attributes with an array of their error messages.

Source: show | on GitHub

def messages hash = to_hash hash.default = EMPTY_ARRAY hash.freeze hash end

messages_for(attribute)Link

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"]

Source: show | on GitHub

def messages_for(attribute) where(attribute).map(&:message) end

of_kind?(attribute, type = :invalid)Link

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

Source: show | on GitHub

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

size Link

Returns number of errors.

Source: show | on GitHub

def_delegators :@errors, :each, :clear, :empty?, :size, :uniq!

to_hash(full_messages = false)Link

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"]}

Source: show | on GitHub

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

where(attribute, type = nil, **options)Link

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

Source: show | on GitHub

def where(attribute, type = nil, **options) attribute, type, options = normalize_arguments(attribute, type, **options) @errors.select { |error| error.match?(attribute, type, **options) } end