class ActiveModel::Errors
Active Model Errors¶ ↑
Provides a modified OrderedHash
that you can include in your
object for handling error messages and interacting with Action Pack
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, "can not 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 Person.human_attribute_name(attr, options = {}) attr end def Person.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:
p = Person.new p.validate! # => ["can not be nil"] p.errors.full_messages # => ["name can not be nil"] # etc..
Constants
- CALLBACKS_OPTIONS
Attributes
Public Class Methods
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 lib/active_model/errors.rb, line 76 def initialize(base) @base = base @messages = ActiveSupport::OrderedHash.new end
Public Instance Methods
When passed a symbol or a name of a method, returns an array of errors for the method.
p.errors[:name] # => ["can not be nil"] p.errors['name'] # => ["can not be nil"]
# File lib/active_model/errors.rb, line 125 def [](attribute) get(attribute.to_sym) || set(attribute.to_sym, []) end
Adds to the supplied attribute the supplied error message.
p.errors[:name] = "must be set" p.errors[:name] # => ['must be set']
# File lib/active_model/errors.rb, line 133 def []=(attribute, error) self[attribute] << error end
Adds message
to the error messages on attribute
.
More than one error can be added to the same attribute
. If no
message
is supplied, :invalid
is assumed.
If message
is a symbol, it will be translated using the
appropriate scope (see translate_error
). If
message
is a proc, it will be called, allowing for things like
Time.now
to be used within an error.
# File lib/active_model/errors.rb, line 232 def add(attribute, message = nil, options = {}) message = normalize_message(attribute, message, options) if options[:strict] raise ActiveModel::StrictValidationFailed, full_message(attribute, message) end self[attribute] << message end
Will add an error message to each of the attributes in
attributes
that is blank (using Object#blank?).
# File lib/active_model/errors.rb, line 251 def add_on_blank(attributes, options = {}) [attributes].flatten.each do |attribute| value = @base.send(:read_attribute_for_validation, attribute) add(attribute, :blank, options) if value.blank? end end
Will add an error message to each of the attributes in
attributes
that is empty.
# File lib/active_model/errors.rb, line 242 def add_on_empty(attributes, options = {}) [attributes].flatten.each do |attribute| value = @base.send(:read_attribute_for_validation, attribute) is_empty = value.respond_to?(:empty?) ? value.empty? : false add(attribute, :empty, options) if value.nil? || is_empty end end
Returns true if an error on the attribute with the given message is
present, false otherwise. message
is treated the same as for
add
.
p.errors.add :name, :blank p.errors.added? :name, :blank # => true
# File lib/active_model/errors.rb, line 262 def added?(attribute, message = nil, options = {}) message = normalize_message(attribute, message, options) self[attribute].include? message end
Returns an ActiveSupport::OrderedHash that can be used as the JSON representation for this object.
# File lib/active_model/errors.rb, line 218 def as_json(options=nil) to_hash end
Clear the messages
# File lib/active_model/errors.rb, line 95 def clear messages.clear end
Returns the number of error messages.
p.errors.add(:name, "can't be blank") p.errors.count # => 1 p.errors.add(:name, "must be specified") p.errors.count # => 2
# File lib/active_model/errors.rb, line 191 def count to_a.size end
Delete messages for key
# File lib/active_model/errors.rb, line 116 def delete(key) messages.delete(key) 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.
p.errors.add(:name, "can't be blank") p.errors.each do |attribute, errors_array| # Will yield :name and "can't be blank" end p.errors.add(:name, "must be specified") p.errors.each do |attribute, errors_array| # Will yield :name and "can't be blank" # then yield :name and "must be specified" end
# File lib/active_model/errors.rb, line 151 def each messages.each_key do |attribute| self[attribute].each { |error| yield attribute, error } end end
Returns true if no errors are found, false otherwise. If the error message is a string it can be empty.
# File lib/active_model/errors.rb, line 197 def empty? all? { |k, v| v && v.empty? && !v.is_a?(String) } end
Returns a full message for a given attribute.
company.errors.full_message(:name, "is invalid") # => "Name is invalid"
# File lib/active_model/errors.rb, line 285 def full_message(attribute, message) return message if attribute == :base attr_name = attribute.to_s.gsub('.', '_').humanize attr_name = @base.class.human_attribute_name(attribute, :default => attr_name) I18n.t(:"errors.format", { :default => "%{attribute} %{message}", :attribute => attr_name, :message => message }) end
Returns all the full error messages in an array.
class Company validates_presence_of :name, :address, :email validates_length_of :name, :in => 5..30 end company = Company.create(:address => '123 First St.') company.errors.full_messages # => ["Name is too short (minimum is 5 characters)", "Name can't be blank", "Email can't be blank"]
# File lib/active_model/errors.rb, line 277 def full_messages map { |attribute, message| full_message(attribute, message) } end
Translates an error message in its default scope
(activemodel.errors.messages
).
Error messages are first looked up in
models.MODEL.attributes.ATTRIBUTE.MESSAGE
, if it's not
there, it's looked up in 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 theactivemodel.errors
scope) -
activemodel.errors.messages.blank
-
errors.attributes.title.blank
-
errors.messages.blank
# File lib/active_model/errors.rb, line 320 def generate_message(attribute, type = :invalid, options = {}) type = options.delete(:message) if options[:message].is_a?(Symbol) if @base.class.respond_to?(:i18n_scope) defaults = @base.class.lookup_ancestors.map do |klass| [ :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.i18n_key}.attributes.#{attribute}.#{type}", :"#{@base.class.i18n_scope}.errors.models.#{klass.model_name.i18n_key}.#{type}" ] end else defaults = [] end defaults << options.delete(:message) defaults << :"#{@base.class.i18n_scope}.errors.messages.#{type}" if @base.class.respond_to?(:i18n_scope) defaults << :"errors.attributes.#{attribute}.#{type}" defaults << :"errors.messages.#{type}" defaults.compact! defaults.flatten! key = defaults.shift value = (attribute != :base ? @base.send(:read_attribute_for_validation, attribute) : nil) options = { :default => defaults, :model => @base.class.model_name.human, :attribute => @base.class.human_attribute_name(attribute), :value => value }.merge(options) I18n.translate(key, options) end
Get messages for key
# File lib/active_model/errors.rb, line 106 def get(key) messages[key] end
Do the error messages include an error with key error
?
# File lib/active_model/errors.rb, line 100 def include?(error) (v = messages[error]) && v.any? end
# File lib/active_model/errors.rb, line 81 def initialize_dup(other) @messages = other.messages.dup end
Returns all message keys
# File lib/active_model/errors.rb, line 173 def keys messages.keys end
Set messages for key
to value
# File lib/active_model/errors.rb, line 111 def set(key, value) messages[key] = value end
Returns the number of error messages.
p.errors.add(:name, "can't be blank") p.errors.size # => 1 p.errors.add(:name, "must be specified") p.errors.size # => 2
# File lib/active_model/errors.rb, line 163 def size values.flatten.size end
Returns an array of error messages, with the attribute name included
p.errors.add(:name, "can't be blank") p.errors.add(:name, "must be specified") p.errors.to_a # => ["name can't be blank", "name must be specified"]
# File lib/active_model/errors.rb, line 182 def to_a full_messages end
# File lib/active_model/errors.rb, line 222 def to_hash messages.dup end
Returns an xml formatted representation of the Errors hash.
p.errors.add(:name, "can't be blank") p.errors.add(:name, "must be specified") p.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 lib/active_model/errors.rb, line 213 def to_xml(options={}) to_a.to_xml options.reverse_merge(:root => "errors", :skip_types => true) end
Returns all message values
# File lib/active_model/errors.rb, line 168 def values messages.values end
Private Instance Methods
# File lib/active_model/errors.rb, line 354 def normalize_message(attribute, message, options) message ||= :invalid if message.is_a?(Symbol) generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS)) elsif message.is_a?(Proc) message.call else message end end