Validation Reflection

Version 1.0.0, 2010-10-08

This plugin adds reflective access to validations

- ModelClass.reflect_on_all_validations
- ModelClass.reflect_on_validations_for(:property)

Both of these methods return arrays containing instances of ActiveRecord::Reflection::MacroReflection. For example

class Person < ActiveRecord::Base
  validates_presence_of :name
  validates_numericality_of :size, :only_integer => true
end

refl = Person.reflect_on_validations_for(:name)
refl[0].macro
# => :validates_presence_of

refl = Person.reflect_on_validations_for(:size)
refl[0].macro
# => :validates_numericality_of
refl[0].options
# => { :only_integer => true }

Customization

Usually, all the standard Rails validations are reflected. You can change this – add or remove validations – in an application-specific initializer,

config/initializers/validation_reflection.rb

In that file change config.reflected_validations to suit your needs. Say, you have a custom validation for email addresses, validates_as_email, then you could add it like this

config.reflected_validations << :validates_as_email

If validates_as_email is implemented in terms of other validation methods, these validations are added to the reflection metadata, too. As that may not be what you want, you can disable reflection for these subordinate validations

config.reflected_validations << {
	:method => :validates_as_email,
	:ignore_subvalidations => true
}

You have to make sure that all reflected validations are defined before this plugin is loaded. To this end, you may have to explicitly set the load order of plugins somewhere in the environment configuration using

config.plugins = [...]

Special Thanks

To Michael Schuerig, michael@schuerig.de for his initial concept and implementation of this plugin.

License

ValidationReflection uses the MIT license. Please check the LICENSE file for more details.