Active Model Errors¶↑
Provides error related functionalities you can include in your object for handling error messages and interacting with Action View helpers.
A minimal implementation could be:
classPerson# Required dependency for ActiveModel::ErrorsextendActiveModel::Namingdefinitialize@errors =ActiveModel::Errors.new(self)endattr_accessor:nameattr_reader:errorsdefvalidate!errors.add(:name,:blank,message:"cannot be nil")ifname.nil?end# The following methods are needed to be minimally implementeddefread_attribute_for_validation(attr)send(attr)enddefself.human_attribute_name(attr,options = {})attrenddefself.lookup_ancestors [self]endend
The last three methods are required in your object forErrors to be able to generate error messages correctly and also handle multiple languages. Of course, if you extend your object withActiveModel::Translation you will not need to implement the last two. Likewise, usingActiveModel::Validations will handle the validation related methods for you.
The above allows you to do:
person =Person.newperson.validate!# => ["cannot be nil"]person.errors.full_messages# => ["name cannot be nil"]# etc..
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Attributes
| [R] | errors | The actual array of |
| [R] | objects | The actual array of |
Class Public methods
new(base)Link
Pass in the instance of the object that is using the errors object.
classPersondefinitialize@errors =ActiveModel::Errors.new(self)endend
Instance Public methods
[](attribute)Link
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"]
add(attribute, type = :invalid, **options)Link
Adds a new error oftype onattribute. More than one error can be added to the sameattribute. If notype is supplied,:invalid is assumed.
person.errors.add(:name)# Adds <#ActiveModel::Error attribute=name, type=invalid>person.errors.add(:name,:not_implemented,message:"must be implemented")# Adds <#ActiveModel::Error attribute=name, type=not_implemented,options={:message=>"must be implemented"}>person.errors.messages# => {:name=>["is invalid", "must be implemented"]}
Iftype is a string, it will be used as error message.
Iftype is a symbol, it will be translated using the appropriate scope (seegenerate_message).
person.errors.add(:name,:blank)person.errors.messages# => {:name=>["can't be blank"]}person.errors.add(:name,:too_long,count:25)person.errors.messages# => ["is too long (maximum is 25 characters)"]
Iftype is a proc, it will be called, allowing for things likeTime.now to be used within an error.
If the:strict option is set totrue, it will raiseActiveModel::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 invalidperson.errors.add(:name,:invalid,strict:NameIsInvalid)# => NameIsInvalid: Name is invalidperson.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 339defadd(attribute,type =:invalid,**options)attribute,type,options =normalize_arguments(attribute,type,**options)error =Error.new(@base,attribute,type,**options)ifexception =options[:strict]exception =ActiveModel::StrictValidationFailedifexception==trueraiseexception,error.full_messageend@errors.append(error)errorend
added?(attribute, type = :invalid, options = {})Link
Returnstrue if an error matches providedattribute andtype, orfalse otherwise.type is treated the same as foradd.
person.errors.add:name,:blankperson.errors.added?:name,:blank# => trueperson.errors.added?:name,"can't be blank"# => true
If the error requires options, then it returnstrue with the correct options, orfalse with incorrect or missing options.
person.errors.add:name,:too_long,count:25person.errors.added?:name,:too_long,count:25# => trueperson.errors.added?:name,"is too long (maximum is 25 characters)"# => trueperson.errors.added?:name,:too_long,count:24# => falseperson.errors.added?:name,:too_long# => falseperson.errors.added?:name,"is too long"# => false
# File activemodel/lib/active_model/errors.rb, line 369defadded?(attribute,type =:invalid,options = {})attribute,type,options =normalize_arguments(attribute,type,**options)iftype.is_a?Symbol@errors.any? {|error|error.strict_match?(attribute,type,**options) }elsemessages_for(attribute).include?(type)endend
as_json(options = nil)Link
Returns aHash 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"]}
attribute_names()Link
Returns all error attribute names
person.errors.messages# => {:name=>["cannot be nil", "must be specified"]}person.errors.attribute_names# => [:name]
clearLink
Clears all errors. Clearing the errors does not, however, make the model valid. The next time the validations are run (for example, viaActiveRecord::Validations#valid?), the errors collection will be filled again if any validations fail.
Source:on GitHub
# File activemodel/lib/active_model/errors.rb, line 77delete(attribute, type = nil, **options)Link
Delete messages forkey. 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 212defdelete(attribute,type =nil,**options)attribute,type,options =normalize_arguments(attribute,type,**options)matches =where(attribute,type,**options)matches.eachdo|error|@errors.delete(error)endmatches.map(&:message).presenceend
each(&block)Link
Iterates through each error object.
person.errors.add(:name, :too_short, count: 2)person.errors.each do |error| # Will yield <#ActiveModel::Error attribute=name, type=too_short, options={:count=>3}>endSource:on GitHub
# File activemodel/lib/active_model/errors.rb, line 64empty?Link
Returns true if there are no errors.
Source:on GitHub
# File activemodel/lib/active_model/errors.rb, line 87full_message(attribute, message)Link
Returns a full message for a given attribute.
person.errors.full_message(:name,'is invalid')# => "Name is invalid"
full_messages()Link
Returns all the full error messages in an array.
classPersonvalidates_presence_of:name,:address,:emailvalidates_length_of:name,in:5..30endperson =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"]
full_messages_for(attribute)Link
Returns all the full error messages for a given attribute in an array.
classPersonvalidates_presence_of:name,:emailvalidates_length_of:name,in:5..30endperson =Person.create()person.errors.full_messages_for(:name)# => ["Name is too short (minimum is 5 characters)", "Name can't be blank"]
generate_message(attribute, type = :invalid, options = {})Link
Translates an error message in its default scope (activemodel.errors.messages).
Error messages are first looked up inactivemodel.errors.models.MODEL.attributes.ATTRIBUTE.MESSAGE, if it’s not there, it’s looked up inactivemodel.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 haveclass Admin < User; end and you wanted the translation for the:blank error message for thetitle attribute, it looks for these translations:
activemodel.errors.models.admin.attributes.title.blankactivemodel.errors.models.admin.blankactivemodel.errors.models.user.attributes.title.blankactivemodel.errors.models.user.blankany default you provided through the
optionshash (in theactivemodel.errorsscope)activemodel.errors.messages.blankerrors.attributes.title.blankerrors.messages.blank
group_by_attribute()Link
import(error, override_options = {})Link
Imports one error. Imported errors are wrapped as aNestedError, providing access to original error object. If attribute or type needs to be overridden, useoverride_options.
Options¶↑
:attribute- Override the attribute the error belongs to.:type- Override type of the error.
include?(attribute)Link
Returnstrue if the error messages include an error for the given keyattribute,false otherwise.
person.errors.messages# => {:name=>["cannot be nil"]}person.errors.include?(:name)# => trueperson.errors.include?(:age)# => false
merge!(other)Link
Merges the errors fromother, eachError wrapped asNestedError.
Parameters¶↑
other- TheActiveModel::Errorsinstance.
Examples¶↑
person.errors.merge!(other)
messages_for(attribute)Link
Returns all the error messages for a given attribute in an array.
classPersonvalidates_presence_of:name,:emailvalidates_length_of:name,in:5..30endperson =Person.create()person.errors.messages_for(:name)# => ["is too short (minimum is 5 characters)", "can't be blank"]
of_kind?(attribute, type = :invalid)Link
Returnstrue if an error on the attribute with the given type is present, orfalse otherwise.type is treated the same as foradd.
person.errors.add:ageperson.errors.add:name,:too_long,count:25person.errors.of_kind?:age# => trueperson.errors.of_kind?:name# => falseperson.errors.of_kind?:name,:too_long# => trueperson.errors.of_kind?:name,"is too long (maximum is 25 characters)"# => trueperson.errors.of_kind?:name,:not_too_long# => falseperson.errors.of_kind?:name,"is too long"# => false
sizeLink
Returns number of errors.
to_a()Link
to_hash(full_messages = false)Link
Returns aHash of attributes with their error messages. Iffull_messages istrue, it will contain full messages (seefull_message).
person.errors.to_hash# => {:name=>["cannot be nil"]}person.errors.to_hash(true)# => {:name=>["name cannot be nil"]}
where(attribute, type = nil, **options)Link
Search for errors matchingattribute,type, oroptions.
Only supplied params will be matched.
person.errors.where(:name)# => all name errors.person.errors.where(:name,:too_short)# => all name errors being too shortperson.errors.where(:name,:too_short,minimum:2)# => all name errors being too short and minimum is 2