Class: ActiveModel::Errors

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/active_model/errors.rb

Overview

Active Model Errors

Provides a modified Hash that 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..

Constant Summary collapse

CALLBACKS_OPTIONS = 
[:if, :unless, :on, :allow_nil, :allow_blank, :strict]
MESSAGE_OPTIONS = 
[:message]

Class Attribute Summary collapse

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(base) ⇒ 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



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# File 'lib/active_model/errors.rb', line 79

def initialize(base)
  @base     = base
  @messages = apply_default_array({})
  @details = apply_default_array({})
end

Class Attribute Details

.i18n_customize_full_message ⇒ Object

:nodoc:



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# File 'lib/active_model/errors.rb', line 66

def i18n_customize_full_message
  @i18n_customize_full_message
end

Instance Attribute Details

#details ⇒ Object (readonly)

Returns the value of attribute details.



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# File 'lib/active_model/errors.rb', line 70

def details
  @details
end

#messages ⇒ Object (readonly)

Returns the value of attribute messages.



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# File 'lib/active_model/errors.rb', line 70

def messages
  @messages
end

Instance Method Details

#[](attribute) ⇒ Object

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"]



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# File 'lib/active_model/errors.rb', line 165

def [](attribute)
  messages[attribute.to_sym]
end

#add(attribute, message = :invalid, options = {}) ⇒ Object

Adds message to the error messages and used validator type to details on attribute. More than one error can be added to the same attribute. If no message is supplied, :invalid is assumed.

person.errors.add(:name)
# => ["is invalid"]
person.errors.add(:name, :not_implemented, message: "must be implemented")
# => ["is invalid", "must be implemented"]

person.errors.messages
# => {:name=>["is invalid", "must be implemented"]}

person.errors.details
# => {:name=>[{error: :not_implemented}, {error: :invalid}]}

If message is a symbol, it will be translated using the appropriate scope (see generate_message).

If message 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}]}



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# File 'lib/active_model/errors.rb', line 311

def add(attribute, message = :invalid, options = {})
  message = message.call if message.respond_to?(:call)
  detail  = normalize_detail(message, options)
  message = normalize_message(attribute, message, options)
  if exception = options[:strict]
    exception = ActiveModel::StrictValidationFailed if exception == true
    raise exception, full_message(attribute, message)
  end

  details[attribute.to_sym]  << detail
  messages[attribute.to_sym] << message
end

#added?(attribute, message = :invalid, options = {}) ⇒ Boolean

Returns true if an error on the attribute with the given message is present, or false otherwise. message 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 message 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

Returns:

  • (Boolean) 


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# File 'lib/active_model/errors.rb', line 340

def added?(attribute, message = :invalid, options = {})
  message = message.call if message.respond_to?(:call)

  if message.is_a? Symbol
    details[attribute.to_sym].include? normalize_detail(message, options)
  else
    self[attribute].include? message
  end
end

#as_json(options = nil) ⇒ Object

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"]}



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# File 'lib/active_model/errors.rb', line 251

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

#clear ⇒ Object

Clear the error messages.

person.errors.full_messages # => ["name cannot be nil"]
person.errors.clear
person.errors.full_messages # => []



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# File 'lib/active_model/errors.rb', line 131

def clear
  messages.clear
  details.clear
end

#copy!(other) ⇒ Object

Copies the errors from other.

other - The ActiveModel::Errors instance.

Examples

person.errors.copy!(other)



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# File 'lib/active_model/errors.rb', line 98

def copy!(other) # :nodoc:
  @messages = other.messages.dup
  @details  = other.details.dup
end

#delete(key) ⇒ Object

Delete messages for key. Returns the deleted messages.

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



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# File 'lib/active_model/errors.rb', line 154

def delete(key)
  attribute = key.to_sym
  details.delete(attribute)
  messages.delete(attribute)
end

#each ⇒ Object

Iterates through each error key, value pair in the error messages hash. Yields the attribute and the error for that attribute. If the attribute has more than one error message, yields once for each error message.

person.errors.add(:name, :blank, message: "can't be blank")
person.errors.each do |attribute, error|
  # Will yield :name and "can't be blank"
end

person.errors.add(:name, :not_specified, message: "must be specified")
person.errors.each do |attribute, error|
  # Will yield :name and "can't be blank"
  # then yield :name and "must be specified"
end



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# File 'lib/active_model/errors.rb', line 183

def each
  messages.each_key do |attribute|
    messages[attribute].each { |error| yield attribute, error }
  end
end

#empty? ⇒ Boolean Also known as: blank?

Returns true if no errors are found, false otherwise. If the error message is a string it can be empty.

person.errors.full_messages # => ["name cannot be nil"]
person.errors.empty?        # => false

Returns:

  • (Boolean) 


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# File 'lib/active_model/errors.rb', line 225

def empty?
  size.zero?
end

#full_message(attribute, message) ⇒ Object

Returns a full message for a given attribute.

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

The ‘“%attribute %message”` error format can be overridden with either

  • activemodel.errors.models.person/contacts/addresses.attributes.street.format

  • activemodel.errors.models.person/contacts/addresses.format

  • activemodel.errors.models.person.attributes.name.format

  • activemodel.errors.models.person.format

  • errors.format



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# File 'lib/active_model/errors.rb', line 412

def full_message(attribute, message)
  return message if attribute == :base
  attribute = attribute.to_s

  if self.class.i18n_customize_full_message && @base.class.respond_to?(:i18n_scope)
    attribute = attribute.remove(/\[\d\]/)
    parts = attribute.split(".")
    attribute_name = parts.pop
    namespace = parts.join("/") unless parts.empty?
    attributes_scope = "#{@base.class.i18n_scope}.errors.models"

    if namespace
      defaults = @base.class.lookup_ancestors.map do |klass|
        [
          :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.attributes.#{attribute_name}.format",
          :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.format",
        ]
      end
    else
      defaults = @base.class.lookup_ancestors.map do |klass|
        [
          :"#{attributes_scope}.#{klass.model_name.i18n_key}.attributes.#{attribute_name}.format",
          :"#{attributes_scope}.#{klass.model_name.i18n_key}.format",
        ]
      end
    end

    defaults.flatten!
  else
    defaults = []
  end

  defaults << :"errors.format"
  defaults << "%{attribute} %{message}"

  attr_name = attribute.tr(".", "_").humanize
  attr_name = @base.class.human_attribute_name(attribute, default: attr_name)

  I18n.t(defaults.shift,
    default:  defaults,
    attribute: attr_name,
    message:   message)
end

#full_messages ⇒ Object Also known as: to_a

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"]



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# File 'lib/active_model/errors.rb', line 381

def full_messages
  map { |attribute, message| full_message(attribute, message) }
end

#full_messages_for(attribute) ⇒ Object

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"]



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# File 'lib/active_model/errors.rb', line 396

def full_messages_for(attribute)
  attribute = attribute.to_sym
  messages[attribute].map { |message| full_message(attribute, message) }
end

#generate_message(attribute, type = :invalid, options = {}) ⇒ Object

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



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# File 'lib/active_model/errors.rb', line 480

def generate_message(attribute, type = :invalid, options = {})
  type = options.delete(:message) if options[:message].is_a?(Symbol)
  value = (attribute != :base ? @base.send(:read_attribute_for_validation, attribute) : nil)

  options = {
    model: @base.model_name.human,
    attribute: @base.class.human_attribute_name(attribute),
    value: value,
    object: @base
  }.merge!(options)

  if @base.class.respond_to?(:i18n_scope)
    i18n_scope = @base.class.i18n_scope.to_s
    defaults = @base.class.lookup_ancestors.flat_map do |klass|
      [ :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}",
        :"#{i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ]
    end
    defaults << :"#{i18n_scope}.errors.messages.#{type}"

    catch(:exception) do
      translation = I18n.translate(defaults.first, **options.merge(default: defaults.drop(1), throw: true))
      return translation unless translation.nil?
    end unless options[:message]
  else
    defaults = []
  end

  defaults << :"errors.attributes.#{attribute}.#{type}"
  defaults << :"errors.messages.#{type}"

  key = defaults.shift
  defaults = options.delete(:message) if options[:message]
  options[:default] = defaults

  I18n.translate(key, **options)
end

#include?(attribute) ⇒ Boolean Also known as: has_key?, key?

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

Returns:

  • (Boolean) 


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# File 'lib/active_model/errors.rb', line 142

def include?(attribute)
  attribute = attribute.to_sym
  messages.key?(attribute) && messages[attribute].present?
end

#init_with(coder) ⇒ Object

:nodoc:



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# File 'lib/active_model/errors.rb', line 527

def init_with(coder) # :nodoc:
  coder.map.each { |k, v| instance_variable_set(:"@#{k}", v) }
  @details ||= {}
  apply_default_array(@messages)
  apply_default_array(@details)
end

#initialize_dup(other) ⇒ Object

:nodoc:



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# File 'lib/active_model/errors.rb', line 85

def initialize_dup(other) # :nodoc:
  @messages = other.messages.dup
  @details  = other.details.deep_dup
  super
end

#keys ⇒ Object

Returns all message keys.

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



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# File 'lib/active_model/errors.rb', line 214

def keys
  messages.select do |key, value|
    !value.empty?
  end.keys
end

#marshal_dump ⇒ Object

:nodoc:



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# File 'lib/active_model/errors.rb', line 517

def marshal_dump # :nodoc:
  [@base, without_default_proc(@messages), without_default_proc(@details)]
end

#marshal_load(array) ⇒ Object

:nodoc:



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# File 'lib/active_model/errors.rb', line 521

def marshal_load(array) # :nodoc:
  @base, @messages, @details = array
  apply_default_array(@messages)
  apply_default_array(@details)
end

#merge!(other) ⇒ Object

Merges the errors from other.

other - The ActiveModel::Errors instance.

Examples

person.errors.merge!(other)



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# File 'lib/active_model/errors.rb', line 110

def merge!(other)
  @messages.merge!(other.messages) { |_, ary1, ary2| ary1 + ary2 }
  @details.merge!(other.details) { |_, ary1, ary2| ary1 + ary2 }
end

#of_kind?(attribute, message = :invalid) ⇒ Boolean

Returns true if an error on the attribute with the given message is present, or false otherwise. message 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

Returns:

  • (Boolean) 


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# File 'lib/active_model/errors.rb', line 361

def of_kind?(attribute, message = :invalid)
  message = message.call if message.respond_to?(:call)

  if message.is_a? Symbol
    details[attribute.to_sym].map { |e| e[:error] }.include? message
  else
    self[attribute].include? message
  end
end

#size ⇒ Object Also known as: count

Returns the number of error messages.

person.errors.add(:name, :blank, message: "can't be blank")
person.errors.size # => 1
person.errors.add(:name, :not_specified, message: "must be specified")
person.errors.size # => 2



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# File 'lib/active_model/errors.rb', line 195

def size
  values.flatten.size
end

#slice!(*keys) ⇒ Object

Removes all errors except the given keys. Returns a hash containing the removed errors.

person.errors.keys                  # => [:name, :age, :gender, :city]
person.errors.slice!(:age, :gender) # => { :name=>["cannot be nil"], :city=>["cannot be nil"] }
person.errors.keys                  # => [:age, :gender]



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# File 'lib/active_model/errors.rb', line 120

def slice!(*keys)
  keys = keys.map(&:to_sym)
  @details.slice!(*keys)
  @messages.slice!(*keys)
end

#to_hash(full_messages = false) ⇒ Object

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"]}



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# File 'lib/active_model/errors.rb', line 260

def to_hash(full_messages = false)
  if full_messages
    messages.each_with_object({}) do |(attribute, array), messages|
      messages[attribute] = array.map { |message| full_message(attribute, message) }
    end
  else
    without_default_proc(messages)
  end
end

#to_xml(options = {}) ⇒ Object

Returns an xml formatted representation of the Errors hash.

person.errors.add(:name, :blank, message: "can't be blank")
person.errors.add(:name, :not_specified, message: "must be specified")
person.errors.to_xml
# =>
#  <?xml version=\"1.0\" encoding=\"UTF-8\"?>
#  <errors>
#    <error>name can't be blank</error>
#    <error>name must be specified</error>
#  </errors>



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# File 'lib/active_model/errors.rb', line 241

def to_xml(options = {})
  to_a.to_xml({ root: "errors", skip_types: true }.merge!(options))
end

#values ⇒ Object

Returns all message values.

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



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# File 'lib/active_model/errors.rb', line 204

def values
  messages.select do |key, value|
    !value.empty?
  end.values
end