Normalizes a given value using normalizations declared for name.

Examples

class User < ActiveRecord::Base
  normalizes :email, with: -> email { email.strip.downcase }
end

User.normalize_value_for(:email, " CRUISE-CONTROL@EXAMPLE.COM\n")
# => "cruise-control@example.com"

Declares a normalization for one or more attributes. The normalization is applied when the attribute is assigned or updated, and the normalized value will be persisted to the database. The normalization is also applied to the corresponding keyword argument of query methods. This allows a record to be created and later queried using unnormalized values.

However, to prevent confusion, the normalization will not be applied when the attribute is fetched from the database. This means that if a record was persisted before the normalization was declared, the record’s attribute will not be normalized until either it is assigned a new value, or it is explicitly migrated via Normalization#normalize_attribute.

Because the normalization may be applied multiple times, it should be idempotent. In other words, applying the normalization more than once should have the same result as applying it only once.

By default, the normalization will not be applied to nil values. This behavior can be changed with the :apply_to_nil option.

Options

• :with - Any callable object that accepts the attribute’s value as its sole argument, and returns it normalized.

• :apply_to_nil - Whether to apply the normalization to nil values. Defaults to false.

Examples

class User < ActiveRecord::Base
  normalizes :email, with: -> email { email.strip.downcase }
  normalizes :phone, with: -> phone { phone.delete("^0-9").delete_prefix("1") }
end

user = User.create(email: " CRUISE-CONTROL@EXAMPLE.COM\n")
user.email                  # => "cruise-control@example.com"

user = User.find_by(email: "\tCRUISE-CONTROL@EXAMPLE.COM ")
user.email                  # => "cruise-control@example.com"
user.email_before_type_cast # => "cruise-control@example.com"

User.where(email: "\tCRUISE-CONTROL@EXAMPLE.COM ").count         # => 1
User.where(["email = ?", "\tCRUISE-CONTROL@EXAMPLE.COM "]).count # => 0

User.exists?(email: "\tCRUISE-CONTROL@EXAMPLE.COM ")         # => true
User.exists?(["email = ?", "\tCRUISE-CONTROL@EXAMPLE.COM "]) # => false

User.normalize_value_for(:phone, "+1 (555) 867-5309") # => "5558675309"