Custom validation with rails: words with more than 26 characters

ioda006 () — Fri, 21 Mar 2008 19:40:38 GMT

This goes in whatever model you're validating. "Subject" can be any of the symbols in your model and doesn't need the : in front of it.



def validate

	if subject.split.any?{|w| w.length > 26}

		errors.add(:subject, "cannot have words more than 26 consecutive characters")

	end

end

Validations for Non-ActiveRecord Objects

Namor () — Thu, 05 Jan 2006 02:01:56 GMT

I needed to find a way to use active record validations on non active record items so i went searching and found this blog which is useful for me..
Totally ripped off Peter Donald's blog :P
http://www.realityforge.org/articles/2005/12/02/validations-for-non-activerecord-model-objects

To get this working grab the active_form.rb file and place it in the app/models directory. You can then make your model objects extend ActiveForm and use them like regular ActiveRecord objects.

active_form.rb



# Note ".valid?" method  must occur on object for validates_associated

class ActiveForm

  

  def initialize(attributes = nil)

    if attributes

      attributes.each do |key,value|

        send(key.to_s + '=', value)

      end

    end

    yield self if block_given?

  end



  def [](key)

    instance_variable_get("@#{key}")

  end



  def method_missing( method_id, *args )

    if md = /_before_type_cast$/.match(method_id.to_s)

      attr_name = md.pre_match

      return self[attr_name] if self.respond_to?(attr_name)

    end

    super

  end



protected 

  def raise_not_implemented_error(*params)

    ValidatingModel.raise_not_implemented_error(*params)

  end



  def self.human_attribute_name(attribute_key_name)

    attribute_key_name.humanize

  end



  def new_record?

    true

  end



  # these methods must be defined before include

  alias save raise_not_implemented_error

  alias update_attribute raise_not_implemented_error



public

  include ActiveRecord::Validations



protected 



  # the following methods must be defined after include so that they overide

  # methods previously included

  alias save! raise_not_implemented_error



  class << self

    def raise_not_implemented_error(*params)

      raise NotImplementedError

    end



    alias validates_uniqueness_of raise_not_implemented_error

    alias create! raise_not_implemented_error

    alias validate_on_create raise_not_implemented_error

    alias validate_on_update raise_not_implemented_error

    alias save_with_validation raise_not_implemented_error    

  end

end



require 'dispatcher'

class Dispatcher

  class << self

    if ! method_defined?(:form_original_reset_application!) 

      alias :form_original_reset_application! :reset_application!

      def reset_application!

        form_original_reset_application!

        Dependencies.remove_subclasses_for(ActiveForm) if defined?(ActiveForm)

      end

    end

  end

end

Defining a custom validates in rails

zzzrByte (Tal Ater) — Wed, 19 Oct 2005 21:47:46 GMT

in the model:



class User < ActiveRecord::Base

  require 'validations'



  validates_positive_or_zero :number

  

end

in /lib/validations.rb:



def validates_positive_or_zero(*attr_names)

  configuration = { :message => "Cannot be negative" }

  configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

  validates_each attr_names do |m, a, v| m.errors.add(a, configuration[:message]) if v<0 end

end

DZone Snippets: validates code

Custom validation with rails: words with more than 26 characters

Validations for Non-ActiveRecord Objects

Defining a custom validates in rails