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::Translations 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..
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 87 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 95 def []=(attribute, error) self[attribute.to_sym] << error end
Adds message
to the error messages on attribute
,
which will be returned on a call to on(attribute)
for the same
attribute. More than one error can be added to the same
attribute
in which case an array will be returned on a call to
on(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 185 def add(attribute, message = nil, options = {}) message ||= :invalid if message.is_a?(Symbol) message = generate_message(attribute, message, options.except(*CALLBACKS_OPTIONS)) elsif message.is_a?(Proc) message = message.call 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 214 def add_on_blank(attributes, options = {}) if options && !options.is_a?(Hash) options = { :message => options } ActiveSupport::Deprecation.warn "ActiveModel::Errors#add_on_blank(attributes, custom_message) has been deprecated.\n" + "Instead of passing a custom_message pass an options Hash { :message => custom_message }." end [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 198 def add_on_empty(attributes, options = {}) if options && !options.is_a?(Hash) options = { :message => options } ActiveSupport::Deprecation.warn "ActiveModel::Errors#add_on_empty(attributes, custom_message) has been deprecated.\n" + "Instead of passing a custom_message pass an options Hash { :message => custom_message }." end [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 an ActiveSupport::OrderedHash that can be used as the JSON representation for this object.
# File lib/active_model/errors.rb, line 168 def as_json(options=nil) to_hash 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 143 def count to_a.size 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 113 def each each_key do |attribute| self[attribute].each { |error| yield attribute, error } end end
Returns true if there are any errors, false if not.
# File lib/active_model/errors.rb, line 148 def empty? all? { |k, v| v && v.empty? } 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", "Address can't be blank"]
# File lib/active_model/errors.rb, line 238 def full_messages full_messages = [] each do |attribute, messages| messages = Array.wrap(messages) next if messages.empty? if attribute == :base messages.each {|m| full_messages << m } else attr_name = attribute.to_s.gsub('.', '_').humanize attr_name = @base.class.human_attribute_name(attribute, :default => attr_name) options = { :default => "%{attribute} %{message}", :attribute => attr_name } messages.each do |m| full_messages << I18n.t(:"errors.format", options.merge(:message => m)) end end end full_messages 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:
<ol>
<li>activemodel.errors.models.admin.attributes.title.blank
</li>
<li>activemodel.errors.models.admin.blank
</li>
<li>activemodel.errors.models.user.attributes.title.blank
</li>
<li>activemodel.errors.models.user.blank
</li>
<li>any default you provided through the options
hash
(in the activemodel.errors scope)</li>
<li>activemodel.errors.messages.blank
</li>
<li>errors.attributes.title.blank
</li>
<li>errors.messages.blank
</li> </ol>
# File lib/active_model/errors.rb, line 286 def generate_message(attribute, type = :invalid, options = {}) type = options.delete(:message) if options[:message].is_a?(Symbol) if options[:default] ActiveSupport::Deprecation.warn "Giving :default as validation option to errors.add has been deprecated.\n" + "Please use :message instead." options[:message] = options.delete(:default) end 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 defaults << options.delete(:message) defaults << :"#{@base.class.i18n_scope}.errors.messages.#{type}" 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
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 125 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 134 def to_a full_messages end
# File lib/active_model/errors.rb, line 172 def to_hash hash = ActiveSupport::OrderedHash.new each { |k, v| (hash[k] ||= []) << v } hash 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 163 def to_xml(options={}) to_a.to_xml options.reverse_merge(:root => "errors", :skip_types => true) 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 lib/active_model/errors.rb, line 74 def initialize(base) @base = base super() end