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diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md index 7932853c11..665e97c470 100644 --- a/guides/source/active_record_validations.md +++ b/guides/source/active_record_validations.md @@ -20,7 +20,7 @@ Validations Overview Here's an example of a very simple validation: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -80,7 +80,7 @@ method to determine whether an object is already in the database or not. Consider the following simple Active Record class: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord end ``` @@ -149,13 +149,15 @@ false` as an argument. This technique should be used with caution. ### `valid?` and `invalid?` -To verify whether or not an object is valid, Rails uses the `valid?` method. -You can also use this method on your own. `valid?` triggers your validations +Before saving an Active Record object, Rails runs your validations. +If these validations produce any errors, Rails does not save the object. + +You can also run these validations on your own. `valid?` triggers your validations and returns true if no errors were found in the object, and false otherwise. As you saw above: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -168,11 +170,12 @@ through the `errors.messages` instance method, which returns a collection of err By definition, an object is valid if this collection is empty after running validations. -Note that an object instantiated with `new` will not report errors even if it's -technically invalid, because validations are not run when using `new`. +Note that an object instantiated with `new` will not report errors +even if it's technically invalid, because validations are automatically run +only when the object is saved, such as with the `create` or `save` methods. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -218,7 +221,7 @@ it doesn't verify the validity of the object as a whole. It only checks to see whether there are errors found on an individual attribute of the object. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end @@ -236,13 +239,13 @@ To check which validations failed on an invalid attribute, you can use key to get the symbol of the validator: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true end >> person = Person.new >> person.valid? ->> person.errors.details[:name] #=> [{error: :blank}] +>> person.errors.details[:name] # => [{error: :blank}] ``` Using `details` with custom validators is covered in the [Working with @@ -273,28 +276,41 @@ available helpers. This method validates that a checkbox on the user interface was checked when a form was submitted. This is typically used when the user needs to agree to your application's terms of service, confirm that some text is read, or any similar -concept. This validation is very specific to web applications and this -'acceptance' does not need to be recorded anywhere in your database (if you -don't have a field for it, the helper will just create a virtual attribute). +concept. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :terms_of_service, acceptance: true end ``` This check is performed only if `terms_of_service` is not `nil`. The default error message for this helper is _"must be accepted"_. +You can also pass custom message via the `message` option. + +```ruby +class Person < ApplicationRecord + validates :terms_of_service, acceptance: { message: 'must be abided' } +end +``` -It can receive an `:accept` option, which determines the value that will be -considered acceptance. It defaults to "1" and can be easily changed. +It can also receive an `:accept` option, which determines the allowed values +that will be considered as accepted. It defaults to `['1', true]` and can be +easily changed. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :terms_of_service, acceptance: { accept: 'yes' } + validates :eula, acceptance: { accept: ['TRUE', 'accepted'] } end ``` +This validation is very specific to web applications and this +'acceptance' does not need to be recorded anywhere in your database. If you +don't have a field for it, the helper will just create a virtual attribute. If +the field does exist in your database, the `accept` option must be set to +or include `true` or else the validation will not run. + ### `validates_associated` You should use this helper when your model has associations with other models @@ -302,7 +318,7 @@ and they also need to be validated. When you try to save your object, `valid?` will be called upon each one of the associated objects. ```ruby -class Library < ActiveRecord::Base +class Library < ApplicationRecord has_many :books validates_associated :books end @@ -325,7 +341,7 @@ or a password. This validation creates a virtual attribute whose name is the name of the field that has to be confirmed with "_confirmation" appended. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :email, confirmation: true end ``` @@ -342,12 +358,22 @@ confirmation, make sure to add a presence check for the confirmation attribute (we'll take a look at `presence` later on in this guide): ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :email, confirmation: true validates :email_confirmation, presence: true end ``` +There is also a `:case_sensitive` option that you can use to define whether the +confirmation constraint will be case sensitive or not. This option defaults to +true. + +```ruby +class Person < ApplicationRecord + validates :email, confirmation: { case_sensitive: false } +end +``` + The default error message for this helper is _"doesn't match confirmation"_. ### `exclusion` @@ -356,7 +382,7 @@ This helper validates that the attributes' values are not included in a given set. In fact, this set can be any enumerable object. ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord validates :subdomain, exclusion: { in: %w(www us ca jp), message: "%{value} is reserved." } end @@ -366,7 +392,8 @@ The `exclusion` helper has an option `:in` that receives the set of values that will not be accepted for the validated attributes. The `:in` option has an alias called `:within` that you can use for the same purpose, if you'd like to. This example uses the `:message` option to show how you can include the -attribute's value. +attribute's value. For full options to the message argument please see the +[message documentation](#message). The default error message is _"is reserved"_. @@ -376,7 +403,7 @@ This helper validates the attributes' values by testing whether they match a given regular expression, which is specified using the `:with` option. ```ruby -class Product < ActiveRecord::Base +class Product < ApplicationRecord validates :legacy_code, format: { with: /\A[a-zA-Z]+\z/, message: "only allows letters" } end @@ -392,7 +419,7 @@ This helper validates that the attributes' values are included in a given set. In fact, this set can be any enumerable object. ```ruby -class Coffee < ActiveRecord::Base +class Coffee < ApplicationRecord validates :size, inclusion: { in: %w(small medium large), message: "%{value} is not a valid size" } end @@ -401,7 +428,8 @@ end The `inclusion` helper has an option `:in` that receives the set of values that will be accepted. The `:in` option has an alias called `:within` that you can use for the same purpose, if you'd like to. The previous example uses the -`:message` option to show how you can include the attribute's value. +`:message` option to show how you can include the attribute's value. For full +options please see the [message documentation](#message). The default error message for this helper is _"is not included in the list"_. @@ -411,7 +439,7 @@ This helper validates the length of the attributes' values. It provides a variety of options, so you can specify length constraints in different ways: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, length: { minimum: 2 } validates :bio, length: { maximum: 500 } validates :password, length: { in: 6..20 } @@ -434,27 +462,12 @@ number corresponding to the length constraint being used. You can still use the `:message` option to specify an error message. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :bio, length: { maximum: 1000, too_long: "%{count} characters is the maximum allowed" } end ``` -This helper counts characters by default, but you can split the value in a -different way using the `:tokenizer` option: - -```ruby -class Essay < ActiveRecord::Base - validates :content, length: { - minimum: 300, - maximum: 400, - tokenizer: lambda { |str| str.split(/\s+/) }, - too_short: "must have at least %{count} words", - too_long: "must have at most %{count} words" - } -end -``` - Note that the default error messages are plural (e.g., "is too short (minimum is %{count} characters)"). For this reason, when `:minimum` is 1 you should provide a personalized message or use `presence: true` instead. When @@ -481,7 +494,7 @@ WARNING. Note that the regular expression above allows a trailing newline character. ```ruby -class Player < ActiveRecord::Base +class Player < ApplicationRecord validates :points, numericality: true validates :games_played, numericality: { only_integer: true } end @@ -503,6 +516,8 @@ constraints to acceptable values: * `:less_than_or_equal_to` - Specifies the value must be less than or equal to the supplied value. The default error message for this option is _"must be less than or equal to %{count}"_. +* `:other_than` - Specifies the value must be other than the supplied value. + The default error message for this option is _"must be other than %{count}"_. * `:odd` - Specifies the value must be an odd number if set to true. The default error message for this option is _"must be odd"_. * `:even` - Specifies the value must be an even number if set to true. The @@ -519,7 +534,7 @@ This helper validates that the specified attributes are not empty. It uses the is, a string that is either empty or consists of whitespace. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, :login, :email, presence: true end ``` @@ -529,7 +544,7 @@ whether the associated object itself is present, and not the foreign key used to map the association. ```ruby -class LineItem < ActiveRecord::Base +class LineItem < ApplicationRecord belongs_to :order validates :order, presence: true end @@ -539,7 +554,7 @@ In order to validate associated records whose presence is required, you must specify the `:inverse_of` option for the association: ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord has_many :line_items, inverse_of: :order end ``` @@ -566,7 +581,7 @@ This helper validates that the specified attributes are absent. It uses the is, a string that is either empty or consists of whitespace. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, :login, :email, absence: true end ``` @@ -576,7 +591,7 @@ whether the associated object itself is absent, and not the foreign key used to map the association. ```ruby -class LineItem < ActiveRecord::Base +class LineItem < ApplicationRecord belongs_to :order validates :order, absence: true end @@ -586,7 +601,7 @@ In order to validate associated records whose absence is required, you must specify the `:inverse_of` option for the association: ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord has_many :line_items, inverse_of: :order end ``` @@ -609,7 +624,7 @@ with the same value for a column that you intend to be unique. To avoid that, you must create a unique index on that column in your database. ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord validates :email, uniqueness: true end ``` @@ -621,19 +636,19 @@ There is a `:scope` option that you can use to specify one or more attributes th are used to limit the uniqueness check: ```ruby -class Holiday < ActiveRecord::Base +class Holiday < ApplicationRecord validates :name, uniqueness: { scope: :year, message: "should happen once per year" } end ``` -Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](http://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns. +Should you wish to create a database constraint to prevent possible violations of a uniqueness validation using the `:scope` option, you must create a unique index on both columns in your database. See [the MySQL manual](http://dev.mysql.com/doc/refman/5.7/en/multiple-column-indexes.html) for more details about multiple column indexes or [the PostgreSQL manual](http://www.postgresql.org/docs/current/static/ddl-constraints.html) for examples of unique constraints that refer to a group of columns. There is also a `:case_sensitive` option that you can use to define whether the uniqueness constraint will be case sensitive or not. This option defaults to true. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, uniqueness: { case_sensitive: false } end ``` @@ -656,7 +671,7 @@ class GoodnessValidator < ActiveModel::Validator end end -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates_with GoodnessValidator end ``` @@ -684,7 +699,7 @@ class GoodnessValidator < ActiveModel::Validator end end -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates_with GoodnessValidator, fields: [:first_name, :last_name] end ``` @@ -697,7 +712,7 @@ If your validator is complex enough that you want instance variables, you can easily use a plain old Ruby object instead: ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validate do |person| GoodnessValidator.new(person).validate end @@ -726,7 +741,7 @@ passed to `validates_each` will be tested against it. In the following example, we don't want names and surnames to begin with lower case. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates_each :name, :surname do |record, attr, value| record.errors.add(attr, 'must start with upper case') if value =~ /\A[[:lower:]]/ end @@ -749,12 +764,15 @@ The `:allow_nil` option skips the validation when the value being validated is `nil`. ```ruby -class Coffee < ActiveRecord::Base +class Coffee < ApplicationRecord validates :size, inclusion: { in: %w(small medium large), message: "%{value} is not a valid size" }, allow_nil: true end ``` +For full options to the message argument please see the +[message documentation](#message). + ### `:allow_blank` The `:allow_blank` option is similar to the `:allow_nil` option. This option @@ -762,7 +780,7 @@ will let validation pass if the attribute's value is `blank?`, like `nil` or an empty string for example. ```ruby -class Topic < ActiveRecord::Base +class Topic < ApplicationRecord validates :title, length: { is: 5 }, allow_blank: true end @@ -775,7 +793,37 @@ Topic.create(title: nil).valid? # => true As you've already seen, the `:message` option lets you specify the message that will be added to the `errors` collection when validation fails. When this option is not used, Active Record will use the respective default error message -for each validation helper. +for each validation helper. The `:message` option accepts a `String` or `Proc`. + +A `String` `:message` value can optionally contain any/all of `%{value}`, +`%{attribute}`, and `%{model}` which will be dynamically replaced when +validation fails. This replacement is done using the I18n gem, and the +placeholders must match exactly, no spaces are allowed. + +A `Proc` `:message` value is given two arguments: the object being validated, and +a hash with `:model`, `:attribute`, and `:value` key-value pairs. + +```ruby +class Person < ApplicationRecord + # Hard-coded message + validates :name, presence: { message: "must be given please" } + + # Message with dynamic attribute value. %{value} will be replaced with + # the actual value of the attribute. %{attribute} and %{model} also + # available. + validates :age, numericality: { message: "%{value} seems wrong" } + + # Proc + validates :username, + uniqueness: { + # object = person object being validated + # data = { model: "Person", attribute: "Username", value: <username> } + message: ->(object, data) do + "Hey #{object.name}!, #{data[:value]} is taken already! Try again #{Time.zone.tomorrow}" + end + } +end +``` ### `:on` @@ -787,7 +835,7 @@ new record is created or `on: :update` to run the validation only when a record is updated. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord # it will be possible to update email with a duplicated value validates :email, uniqueness: true, on: :create @@ -799,6 +847,25 @@ class Person < ActiveRecord::Base end ``` +You can also use `on:` to define custom context. +Custom contexts need to be triggered explicitly +by passing name of the context to `valid?`, `invalid?` or `save`. + +```ruby +class Person < ApplicationRecord + validates :email, uniqueness: true, on: :account_setup + validates :age, numericality: true, on: :account_setup +end + +person = Person.new +``` + +`person.valid?(:account_setup)` executes both the validations +without saving the model. And `person.save(context: :account_setup)` +validates `person` in `account_setup` context before saving. +On explicit triggers, model is validated by +validations of only that context and validations without context. + Strict Validations ------------------ @@ -806,7 +873,7 @@ You can also specify validations to be strict and raise `ActiveModel::StrictValidationFailed` when the object is invalid. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: { strict: true } end @@ -816,7 +883,7 @@ Person.new.valid? # => ActiveModel::StrictValidationFailed: Name can't be blank There is also the ability to pass a custom exception to the `:strict` option. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :token, presence: true, uniqueness: true, strict: TokenGenerationException end @@ -840,7 +907,7 @@ to the name of a method that will get called right before validation happens. This is the most commonly used option. ```ruby -class Order < ActiveRecord::Base +class Order < ApplicationRecord validates :card_number, presence: true, if: :paid_with_card? def paid_with_card? @@ -856,7 +923,7 @@ contain valid Ruby code. You should use this option only when the string represents a really short condition. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :surname, presence: true, if: "name.nil?" end ``` @@ -869,7 +936,7 @@ inline condition instead of a separate method. This option is best suited for one-liners. ```ruby -class Account < ActiveRecord::Base +class Account < ApplicationRecord validates :password, confirmation: true, unless: Proc.new { |a| a.password.blank? } end @@ -881,7 +948,7 @@ Sometimes it is useful to have multiple validations use one condition. It can be easily achieved using `with_options`. ```ruby -class User < ActiveRecord::Base +class User < ApplicationRecord with_options if: :is_admin? do |admin| admin.validates :password, length: { minimum: 10 } admin.validates :email, presence: true @@ -899,7 +966,7 @@ should happen, an `Array` can be used. Moreover, you can apply both `:if` and `:unless` to the same validation. ```ruby -class Computer < ActiveRecord::Base +class Computer < ApplicationRecord validates :mouse, presence: true, if: ["market.retail?", :desktop?], unless: Proc.new { |c| c.trackpad.present? } @@ -953,7 +1020,7 @@ class EmailValidator < ActiveModel::EachValidator end end -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :email, presence: true, email: true end ``` @@ -965,14 +1032,19 @@ own custom validators. You can also create methods that verify the state of your models and add messages to the `errors` collection when they are invalid. You must then -register these methods by using the `validate` class method, passing in the -symbols for the validation methods' names. +register these methods by using the `validate` +([API](http://api.rubyonrails.org/classes/ActiveModel/Validations/ClassMethods.html#method-i-validate)) +class method, passing in the symbols for the validation methods' names. You can pass more than one symbol for each class method and the respective validations will be run in the same order as they were registered. +The `valid?` method will verify that the errors collection is empty, +so your custom validation methods should add errors to it when you +wish validation to fail: + ```ruby -class Invoice < ActiveRecord::Base +class Invoice < ApplicationRecord validate :expiration_date_cannot_be_in_the_past, :discount_cannot_be_greater_than_total_value @@ -990,12 +1062,13 @@ class Invoice < ActiveRecord::Base end ``` -By default such validations will run every time you call `valid?`. It is also -possible to control when to run these custom validations by giving an `:on` -option to the `validate` method, with either: `:create` or `:update`. +By default, such validations will run every time you call `valid?` +or save the object. But it is also possible to control when to run these +custom validations by giving an `:on` option to the `validate` method, +with either: `:create` or `:update`. ```ruby -class Invoice < ActiveRecord::Base +class Invoice < ApplicationRecord validate :active_customer, on: :create def active_customer @@ -1016,7 +1089,7 @@ The following is a list of the most commonly used methods. Please refer to the ` Returns an instance of the class `ActiveModel::Errors` containing all errors. Each key is the attribute name and the value is an array of strings with all errors. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end @@ -1035,7 +1108,7 @@ person.errors.messages # => {} `errors[]` is used when you want to check the error messages for a specific attribute. It returns an array of strings with all error messages for the given attribute, each string with one error message. If there are no errors related to the attribute, it returns an empty array. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end @@ -1060,7 +1133,7 @@ The `add` method lets you add an error message related to a particular attribute The `errors.full_messages` method (or its equivalent, `errors.to_a`) returns the error messages in a user-friendly format, with the capitalized attribute name prepended to each message, as shown in the examples below. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.add(:name, "cannot contain the characters !@#%*()_-+=") end @@ -1078,7 +1151,7 @@ person.errors.full_messages An equivalent to `errors#add` is to use `<<` to append a message to the `errors.messages` array for an attribute: ```ruby - class Person < ActiveRecord::Base + class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.messages[:name] << "cannot contain the characters !@#%*()_-+=" end @@ -1099,7 +1172,7 @@ You can specify a validator type to the returned error details hash using the `errors.add` method. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.add(:name, :invalid_characters) end @@ -1115,7 +1188,7 @@ To improve the error details to contain the unallowed characters set for instanc you can pass additional keys to `errors.add`. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors.add(:name, :invalid_characters, not_allowed: "!@#%*()_-+=") end @@ -1135,7 +1208,7 @@ validator type. You can add error messages that are related to the object's state as a whole, instead of being related to a specific attribute. You can use this method when you want to say that the object is invalid, no matter the values of its attributes. Since `errors[:base]` is an array, you can simply add a string to it and it will be used as an error message. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord def a_method_used_for_validation_purposes errors[:base] << "This person is invalid because ..." end @@ -1147,7 +1220,7 @@ end The `clear` method is used when you intentionally want to clear all the messages in the `errors` collection. Of course, calling `errors.clear` upon an invalid object won't actually make it valid: the `errors` collection will now be empty, but the next time you call `valid?` or any method that tries to save this object to the database, the validations will run again. If any of the validations fail, the `errors` collection will be filled again. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end @@ -1159,9 +1232,9 @@ person.errors[:name] person.errors.clear person.errors.empty? # => true -p.save # => false +person.save # => false -p.errors[:name] +person.errors[:name] # => ["can't be blank", "is too short (minimum is 3 characters)"] ``` @@ -1170,7 +1243,7 @@ p.errors[:name] The `size` method returns the total number of error messages for the object. ```ruby -class Person < ActiveRecord::Base +class Person < ApplicationRecord validates :name, presence: true, length: { minimum: 3 } end |