vanguard's Introduction

vanguard

This library provides external validations for any Ruby class.

History:

It originates from emmanuels aequitas repository with the following changes:

Only support for external validators
Use composable algebra for internals
Will allow serialization to javascript for client side validation (not implemented)
No contextual validators anymore (use additional external validators)
100% code rewrite
Use equalizer and adamantium where possible.

Specifying Validations

require 'vanguard'

class ProgrammingLanguage
  attr_reader :name

  def initialize(name)
    @name = name
  end
end

VALIDATOR = Vanguard::Validator.build do
  validates_presence_of :name
end

ruby = ProgrammingLanguage.new('ruby')

result = VALIDATOR.call(ruby)
result.valid? # => true
result.violations # => #<Set: {}>

other = ProgrammingLanguage.new('')

result = VALIDATOR.call(other)
result.valid? # => false
result.violations # => #<Set: {<Vanguard:::Violation ....>}>

See Vanguard::Macros to learn about the complete collection of validation rules available.

Credits

Markus Schirp mbj
Emmanuel Gomez emmanuel

Working with Validation Errors

If an instance fails one or more validation rules, Vanguard::Violation instances will populate the Vanguard::ViolationSet object that is available through the Vanguard::Result#violations method.

Vanguard currently has no support for generating human readable violation messages!

For example:

result = YOUR_VALIDATOR.call(Account.new(:name => "Jose"))
if result.valid?
  # my_account is valid and can be saved
else
  result.violations.each do |e|
    do_something_with(e)
  end
end