# -*- coding: utf-8 -*-
require 'active_support/core_ext/array/conversions'
require 'active_support/core_ext/string/inflections'
module ActiveModel
# == Active \Model \Errors
#
# Provides a modified +Hash+ 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
# person.validate! # => ["can not be nil"]
# person.errors.full_messages # => ["name can not be nil"]
# # etc..
class Errors
include Enumerable
CALLBACKS_OPTIONS = [:if, :unless, :on, :allow_nil, :allow_blank, :strict]
attr_reader :messages
# 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
@messages = {}
end
def initialize_dup(other) # :nodoc:
@messages = other.messages.dup
super
end
# Clear the error messages.
#
# person.errors.full_messages # => ["name can not be nil"]
# person.errors.clear
# person.errors.full_messages # => []
def clear
messages.clear
end
# Returns +true+ if the error messages include an error for the given key
# +attribute+, +false+ otherwise.
#
# person.errors.messages # => {:name=>["can not be nil"]}
# person.errors.include?(:name) # => true
# person.errors.include?(:age) # => false
def include?(attribute)
(v = messages[attribute]) && v.any?
end
# aliases include?
alias :has_key? :include?
# Get messages for +key+.
#
# person.errors.messages # => {:name=>["can not be nil"]}
# person.errors.get(:name) # => ["can not be nil"]
# person.errors.get(:age) # => nil
def get(key)
messages[key]
end
# Set messages for +key+ to +value+.
#
# person.errors.get(:name) # => ["can not be nil"]
# person.errors.set(:name, ["can't be nil"])
# person.errors.get(:name) # => ["can't be nil"]
def set(key, value)
messages[key] = value
end
# Delete messages for +key+. Returns the deleted messages.
#
# person.errors.get(:name) # => ["can not be nil"]
# person.errors.delete(:name) # => ["can not be nil"]
# person.errors.get(:name) # => nil
def delete(key)
messages.delete(key)
end
# When passed a symbol or a name of a method, returns an array of errors
# for the method.
#
# person.errors[:name] # => ["can not be nil"]
# person.errors['name'] # => ["can not be nil"]
def [](attribute)
get(attribute.to_sym) || set(attribute.to_sym, [])
end
# Adds to the supplied attribute the supplied error message.
#
# person.errors[:name] = "must be set"
# person.errors[:name] # => ['must be set']
def []=(attribute, error)
self[attribute] << error
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, "can't be blank")
# person.errors.each do |attribute, error|
# # Will yield :name and "can't be blank"
# end
#
# person.errors.add(:name, "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
def each
messages.each_key do |attribute|
self[attribute].each { |error| yield attribute, error }
end
end
# Returns the number of error messages.
#
# person.errors.add(:name, "can't be blank")
# person.errors.size # => 1
# person.errors.add(:name, "must be specified")
# person.errors.size # => 2
def size
values.flatten.size
end
# Returns all message values.
#
# person.errors.messages # => {:name=>["can not be nil", "must be specified"]}
# person.errors.values # => [["can not be nil", "must be specified"]]
def values
messages.values
end
# Returns all message keys.
#
# person.errors.messages # => {:name=>["can not be nil", "must be specified"]}
# person.errors.keys # => [:name]
def keys
messages.keys
end
# Returns an array of error messages, with the attribute name included.
#
# person.errors.add(:name, "can't be blank")
# person.errors.add(:name, "must be specified")
# person.errors.to_a # => ["name can't be blank", "name must be specified"]
def to_a
full_messages
end
# Returns the number of error messages.
#
# person.errors.add(:name, "can't be blank")
# person.errors.count # => 1
# person.errors.add(:name, "must be specified")
# person.errors.count # => 2
def count
to_a.size
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 can not be nil"]
# person.errors.empty? # => false
def empty?
all? { |k, v| v && v.empty? && !v.is_a?(String) }
end
# aliases empty?
alias_method :blank?, :empty?
# Returns an xml formatted representation of the Errors hash.
#
# person.errors.add(:name, "can't be blank")
# person.errors.add(:name, "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>
def to_xml(options={})
to_a.to_xml({ :root => "errors", :skip_types => true }.merge!(options))
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.as_json # => {:name=>["can not be nil"]}
# person.as_json(full_messages: true) # => {:name=>["name can not 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.to_hash # => {:name=>["can not be nil"]}
# person.to_hash(true) # => {:name=>["name can not be nil"]}
def to_hash(full_messages = false)
if full_messages
messages = {}
self.messages.each do |attribute, array|
messages[attribute] = array.map { |message| full_message(attribute, message) }
end
messages
else
self.messages.dup
end
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,
# <tt>:invalid</tt> is assumed.
#
# person.errors.add(:name)
# # => ["is invalid"]
# person.errors.add(:name, 'must be implemented')
# # => ["is invalid", "must be implemented"]
#
# person.errors.messages
# # => {:name=>["must be implemented", "is 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
# <tt>Time.now</tt> to be used within an error.
#
# If the <tt>:strict</tt> option is set to true 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, nil, strict: true)
# # => ActiveModel::StrictValidationFailed: name is invalid
# person.errors.add(:name, nil, strict: NameIsInvalid)
# # => NameIsInvalid: name is invalid
#
# person.errors.messages # => {}
def add(attribute, message = nil, options = {})
message = normalize_message(attribute, message, options)
if exception = options[:strict]
exception = ActiveModel::StrictValidationFailed if exception == true
raise exception, full_message(attribute, message)
end
self[attribute] << message
end
# Will add an error message to each of the attributes in +attributes+
# that is empty.
#
# person.errors.add_on_empty(:name)
# person.errors.messages
# # => {:name=>["can't be empty"]}
def add_on_empty(attributes, options = {})
Array(attributes).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
# Will add an error message to each of the attributes in +attributes+ that
# is blank (using Object#blank?).
#
# person.errors.add_on_blank(:name)
# person.errors.messages
# # => {:name=>["can't be blank"]}
def add_on_blank(attributes, options = {})
Array(attributes).each do |attribute|
value = @base.send(:read_attribute_for_validation, attribute)
add(attribute, :blank, options) if value.blank?
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+.
#
# person.errors.add :name, :blank
# person.errors.added? :name, :blank # => true
def added?(attribute, message = nil, options = {})
message = normalize_message(attribute, message, options)
self[attribute].include? 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"]
def full_messages
map { |attribute, message| full_message(attribute, 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)
return message if attribute == :base
attr_name = attribute.to_s.tr('.', '_').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
# Translates an error message in its default scope
# (<tt>activemodel.errors.messages</tt>).
#
# Error messages are first looked up in <tt>models.MODEL.attributes.ATTRIBUTE.MESSAGE</tt>,
# if it's not there, it's looked up in <tt>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 = {})
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
private
def normalize_message(attribute, message, options)
message ||= :invalid
case message
when Symbol
generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS))
when Proc
message.call
else
message
end
end
end
# 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
end
