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..
# File activemodel/lib/active_model/errors.rb, line 79 def initialize(base) @base = base @messages = apply_default_array({}) @details = apply_default_array({}) end
Pass in the instance of the object that is using the errors object.
class Person def initialize @errors = ActiveModel::Errors.new(self) end end
# File activemodel/lib/active_model/errors.rb, line 165 def [](attribute) messages[attribute.to_sym] 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"]
# File activemodel/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
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}]}
# File activemodel/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
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
# File activemodel/lib/active_model/errors.rb, line 251 def as_json(options = nil) to_hash(options && options[:full_messages]) end
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"]}
# File activemodel/lib/active_model/errors.rb, line 131 def clear messages.clear details.clear end
Clear the error messages.
person.errors.full_messages # => ["name cannot be nil"] person.errors.clear person.errors.full_messages # => []
# File activemodel/lib/active_model/errors.rb, line 154 def delete(key) attribute = key.to_sym details.delete(attribute) messages.delete(attribute) end
Delete messages for key
. Returns the deleted messages.
person.errors[:name] # => ["cannot be nil"] person.errors.delete(:name) # => ["cannot be nil"] person.errors[:name] # => []
# File activemodel/lib/active_model/errors.rb, line 183 def each messages.each_key do |attribute| messages[attribute].each { |error| yield attribute, error } end end
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
# File activemodel/lib/active_model/errors.rb, line 225 def empty? size.zero? end
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
# File activemodel/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
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
# File activemodel/lib/active_model/errors.rb, line 381 def full_messages map { |attribute, message| full_message(attribute, message) } 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"]
# File activemodel/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
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"]
# File activemodel/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
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
# File activemodel/lib/active_model/errors.rb, line 142 def include?(attribute) attribute = attribute.to_sym messages.key?(attribute) && messages[attribute].present? 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
# File activemodel/lib/active_model/errors.rb, line 214 def keys messages.select do |key, value| !value.empty? end.keys end
Returns all message keys.
person.errors.messages # => {:name=>["cannot be nil", "must be specified"]} person.errors.keys # => [:name]
# File activemodel/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
Merges the errors from other
.
other - The ActiveModel::Errors instance.
Examples
person.errors.merge!(other)
# File activemodel/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
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
# File activemodel/lib/active_model/errors.rb, line 195 def size values.flatten.size end
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
# File activemodel/lib/active_model/errors.rb, line 120 def slice!(*keys) keys = keys.map(&:to_sym) @details.slice!(*keys) @messages.slice!(*keys) end
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]
# File activemodel/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
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"]}
# File activemodel/lib/active_model/errors.rb, line 241 def to_xml(options = {}) to_a.to_xml({ root: "errors", skip_types: true }.merge!(options)) end
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>
# File activemodel/lib/active_model/errors.rb, line 204 def values messages.select do |key, value| !value.empty? end.values end
Returns all message values.
person.errors.messages # => {:name=>["cannot be nil", "must be specified"]} person.errors.values # => [["cannot be nil", "must be specified"]]
© 2004–2019 David Heinemeier Hansson
Licensed under the MIT License.