Class: ActiveModel::Errors
Relationships & Source Files | |
Super Chains via Extension / Inclusion / Inheritance | |
Instance Chain:
self,
::Enumerable
|
|
Inherits: | Object |
Defined in: | activemodel/lib/active_model/errors.rb |
Overview
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, "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 Person.human_attribute_name(attr, = {})
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 Translation you will not need to implement the last two. Likewise, using 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. # => ["name cannot be nil"]
# etc..
Constant Summary
-
CALLBACKS_OPTIONS =
# File 'activemodel/lib/active_model/errors.rb', line 60[:if, :unless, :on, :allow_nil, :allow_blank, :strict]
Class Method Summary
-
.new(base) ⇒ Errors
constructor
Pass in the instance of the object that is using the errors object.
Instance Attribute Summary
-
#blank?
readonly
Alias for #empty?.
-
#empty? ⇒ Boolean
(also: #blank?)
readonly
Returns
true
if no errors are found,false
otherwise. - #messages readonly
::Enumerable - Included
#many? | Returns |
Instance Method Summary
-
#[](attribute)
When passed a symbol or a name of a method, returns an array of errors for the method.
-
#[]=(attribute, error)
Adds to the supplied attribute the supplied error message.
-
#add(attribute, message = :invalid, options = {})
Adds
message
to the error messages onattribute
. -
#add_on_blank(attributes, options = {})
Will add an error message to each of the attributes in
attributes
that is blank (using Object#blank?). -
#add_on_empty(attributes, options = {})
Will add an error message to each of the attributes in
attributes
that is empty. -
#added?(attribute, message = :invalid, options = {}) ⇒ Boolean
Returns
true
if an error on the attribute with the given message is present,false
otherwise. -
#as_json(options = nil)
Returns a ::Hash that can be used as the JSON representation for this object.
-
#clear
Clear the error messages.
-
#count
Returns the number of error messages.
-
#delete(key)
Delete messages for
key
. -
#each
Iterates through each error key, value pair in the error messages hash.
-
#full_message(attribute, message)
Returns a full message for a given attribute.
-
#full_messages
Returns all the full error messages in an array.
-
#full_messages_for(attribute)
Returns all the full error messages for a given attribute in an array.
-
#generate_message(attribute, type = :invalid, options = {})
Translates an error message in its default scope (
activemodel.errors.messages
). -
#get(key)
Get messages for
key
. -
#has_key?(attribute)
Alias for #include?.
-
#include?(attribute) ⇒ Boolean
(also: #has_key?, #key?)
Returns
true
if the error messages include an error for the given keyattribute
,false
otherwise. -
#key?(attribute)
Alias for #include?.
-
#keys
Returns all message keys.
-
#set(key, value)
Set messages for
key
tovalue
. -
#size
Returns the number of error messages.
-
#to_a
Returns an array of error messages, with the attribute name included.
-
#to_hash(full_messages = false)
Returns a ::Hash of attributes with their error messages.
-
#to_xml(options = {})
Returns an xml formatted representation of the
Errors
hash. -
#values
Returns all message values.
::Enumerable - Included
Constructor Details
.new(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
# File 'activemodel/lib/active_model/errors.rb', line 71
def initialize(base) @base = base @messages = {} end
Instance Attribute Details
#blank? (readonly)
Alias for #empty?.
# File 'activemodel/lib/active_model/errors.rb', line 222
alias_method :blank?, :empty?
#empty? ⇒ Boolean
(readonly)
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. # => ["name cannot be nil"]
person.errors.empty? # => false
# File 'activemodel/lib/active_model/errors.rb', line 218
def empty? all? { |k, v| v && v.empty? && !v.is_a?(String) } end
#messages (readonly)
[ GitHub ]# File 'activemodel/lib/active_model/errors.rb', line 62
attr_reader :
Instance Method Details
#[](attribute)
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"]
#[]=(attribute, error)
Adds to the supplied attribute the supplied error message.
person.errors[:name] = "must be set"
person.errors[:name] # => ['must be set']
# File 'activemodel/lib/active_model/errors.rb', line 144
def []=(attribute, error) self[attribute] << error end
#add(attribute, message = :invalid, options = {})
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.
person.errors.add(:name)
# => ["is invalid"]
person.errors.add(:name, 'must be implemented')
# => ["is invalid", "must be implemented"]
person.errors.
# => {: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 Time.now
to be used within an error.
If the :strict
option is set to true
, it will raise StrictValidationFailed instead of adding the error. :strict
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. # => {}
attribute
should be set to :base
if the error is not directly associated with a single attribute.
person.errors.add(:base, "either name or email must be present")
person.errors.
# => {:base=>["either name or email must be present"]}
# File 'activemodel/lib/active_model/errors.rb', line 299
def add(attribute, = :invalid, = {}) = (attribute, , ) if exception = [:strict] exception = ActiveModel::StrictValidationFailed if exception == true raise exception, (attribute, ) end self[attribute] << end
#add_on_blank(attributes, options = {})
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.
# => {:name=>["can't be blank"]}
#add_on_empty(attributes, options = {})
Will add an error message to each of the attributes in attributes
that is empty.
person.errors.add_on_empty(:name)
person.errors.
# => {:name=>["can't be empty"]}
# File 'activemodel/lib/active_model/errors.rb', line 315
def add_on_empty(attributes, = {}) 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, ) if value.nil? || is_empty end end
#added?(attribute, message = :invalid, options = {}) ⇒ Boolean
# File 'activemodel/lib/active_model/errors.rb', line 341
def added?(attribute, = :invalid, = {}) = (attribute, , ) self[attribute].include? end
#as_json(options = nil)
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 245
def as_json(=nil) to_hash( && [: ]) end
#clear
Clear the error messages.
person.errors. # => ["name cannot be nil"]
person.errors.clear
person.errors. # => []
# File 'activemodel/lib/active_model/errors.rb', line 86
def clear .clear end
#count
#delete(key)
# File 'activemodel/lib/active_model/errors.rb', line 127
def delete(key) .delete(key) end
#each
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
# File 'activemodel/lib/active_model/errors.rb', line 162
def each .each_key do |attribute| self[attribute].each { |error| yield attribute, error } end end
#full_message(attribute, message)
Returns a full message for a given attribute.
person.errors. (:name, 'is invalid') # => "Name is invalid"
# File 'activemodel/lib/active_model/errors.rb', line 377
def (attribute, ) return 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: }) end
#full_messages
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.
# => ["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 356
def map { |attribute, | (attribute, ) } end
#full_messages_for(attribute)
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. (:name)
# => ["Name is too short (minimum is 5 characters)", "Name can't be blank"]
# File 'activemodel/lib/active_model/errors.rb', line 370
def (attribute) (get(attribute) || []).map { || (attribute, ) } end
#generate_message(attribute, type = :invalid, options = {})
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 'activemodel/lib/active_model/errors.rb', line 412
def (attribute, type = :invalid, = {}) type = .delete(: ) if [: ].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 << .delete(: ) 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) = { default: defaults, model: @base.model_name.human, attribute: @base.class.human_attribute_name(attribute), value: value }.merge!( ) I18n.translate(key, ) end
#get(key)
Get messages for key
.
person.errors. # => {:name=>["cannot be nil"]}
person.errors.get(:name) # => ["cannot be nil"]
person.errors.get(:age) # => nil
# File 'activemodel/lib/active_model/errors.rb', line 109
def get(key) [key] end
#has_key?(attribute)
Alias for #include?.
# File 'activemodel/lib/active_model/errors.rb', line 100
alias :has_key? :include?
#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. # => {:name=>["cannot be nil"]}
person.errors.include?(:name) # => true
person.errors.include?(:age) # => false
# File 'activemodel/lib/active_model/errors.rb', line 96
def include?(attribute) [attribute].present? end
#key?(attribute)
Alias for #include?.
# File 'activemodel/lib/active_model/errors.rb', line 102
alias :key? :include?
#keys
Returns all message keys.
person.errors. # => {:name=>["cannot be nil", "must be specified"]}
person.errors.keys # => [:name]
# File 'activemodel/lib/active_model/errors.rb', line 190
def keys .keys end
#set(key, value)
# File 'activemodel/lib/active_model/errors.rb', line 118
def set(key, value) [key] = value end
#size
# File 'activemodel/lib/active_model/errors.rb', line 174
def size values.flatten.size end
#to_a
# File 'activemodel/lib/active_model/errors.rb', line 199
def to_a end
#to_hash(full_messages = false)
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 254
def to_hash( = false) if self. .each_with_object({}) do |(attribute, array), | [attribute] = array.map { || (attribute, ) } end else self. .dup end end
#to_xml(options = {})
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>
# File 'activemodel/lib/active_model/errors.rb', line 235
def to_xml(={}) to_a.to_xml({ root: "errors", skip_types: true }.merge!( )) end
#values
Returns all message values.
person.errors. # => {:name=>["cannot be nil", "must be specified"]}
person.errors.values # => [["cannot be nil", "must be specified"]]
# File 'activemodel/lib/active_model/errors.rb', line 182
def values .values end