PureValidator
PureValidator is a simple, mostly dependency-free (except i18n
) library to validate your domain Ruby objects.
It keeps the concerns of validation separate from the Entity / Value object itself.
This gives you the option to have different validations rules for different ocasions for the same object in a very clean and unit-testable way.
It is a simple step to separate those concerns, but it will give you unlimited flexibility and save your *SS from debugging entangled and conflicting validations for non-trivial requirements.
Do yourself a favor and start using PureValidator today, you will never look back!
Installation
Add this line to your application's Gemfile:
gem 'pure_validator'
Usage
Let's say you have the following class and you want to validate its instances:
class Contact
attr_accessor :first_name, :last_name, :position, :age, :type,
:email, :color, :status, :stage, :description,
:companies, :address
def to_h
{
first_name: first_name,
last_name: last_name,
position: position,
age: age,
type: type,
email: email,
color: color,
status: status,
stage: stage,
description: description,
companies: (companies||[]).map(&:to_h),
address: (address && address.to_h),
}
end
end
To validate objects of the Contact class define following validator:
class ContactValidator
include PureValidator::Validator
validates :first_name, presence: true, length: { min: 4, max: 7 }
validates :last_name, length: { equal_to: 5 }
validates :position, length: { not_equal_to: 5 }
validates :age, numericality: { greater_than: 0, less_than: 150 }
validates :type, numericality: { greater_than_or_equal_to: 1, less_than_or_equal_to: 5 }
validates :email, email: true
validates :color, regexp: /#\w{6}/
validates :status, inclusion: { in: [:new, :lead] }
validates :stage, exclusion: { in: [:wrong, :bad] }
validate_associated :companies, validator: CompanyValidator
validate :check_description
def check_description(entity, errors)
if entity.description.nil?
errors.add(:description, "can't be empty")
end
end
end
Instantiate the validator and call validate
with a contact object:
errors = ContactValidator.new.validate(contact)
It also works with plain hashes:
errors = ContactValidator.new.validate(contact.to_h)
errors
is a Hash that contains all validation errors.
If the object is valid then errors will be an empty Hash.
Adding own validators
PureValidator can be extended by adding your own validators.
To add a validator define a class with 2 static methods: validate
and validate_options
:
The following example shows the built-in inclusion validator, it validates that specified value is one of the defined values.
class PureValidator::Validators::InclusionValidator
# Validates that given value inscluded in the specified list
# @param value [Object] object to validate
# @parm options [Hash] validation options, e.g. { in: [:small, :medium, :large], message: "not included in the list of allowed items" }
# where :in - list of allowed values,
# message - is a message to return if value is not included in the list
# @return [Array] empty array if object is valid, list of errors otherwise
def self.validate(value, options)
return [] if value.nil?
errors = []
if options[:in]
unless options[:in].include?(value)
errors << (options[:message] || PureValidator::I18n.t('errors.should_be_included_in_list', list: options[:in]))
end
end
errors
end
# Validates that options specified in
# :inclusion are valid
def self.validate_options(options)
raise ArgumentError, "validation options should be a Hash" unless options.is_a?(Hash)
raise ArgumentError, "validation options should have :in option and it should be an array of allowed values" unless options[:in].is_a?(Array)
end
end
And register it in PureValidator:
PureValidator.add_validator(:inclusion, PureValidator::Validators::InclusionValidator)
Now you can use it:
class SomeValidator
include PureValidator::Validator
validates :size, inclusion: { in: [:small, :medium, :large] }
end
Installation
Add this line to your application's Gemfile:
gem 'pure_validator'
And then execute:
$ bundle
Or install it yourself as:
$ gem install pure_validator
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request
Authors
- Albert Gazizov, @deeper4k
- Roman Heinrich, @mindreframer