method

on

v2.3.8 - Show latest stable - 1 note - Class: ActiveRecord::Errors

1.0.0 (0)
1.1.6 (0)
1.2.6 (0)
2.0.3 (22)
2.1.0 (0)
2.2.1 (0)
2.3.8 (0)
3.0.0
3.0.9
3.1.0
3.2.1
3.2.8
3.2.13
4.0.2
4.1.8
4.2.1
4.2.7
4.2.9
5.0.0.1
5.1.7
5.2.3
6.0.0
6.1.3.1
6.1.7.7
7.0.0
7.1.3.2
7.1.3.4
What's this?

on(attribute) public

Returns nil, if no errors are associated with the specified attribute. Returns the error message, if one error is associated with the specified attribute. Returns an array of error messages, if more than one error is associated with the specified attribute.

  class Company < ActiveRecord::Base
    validates_presence_of :name, :address, :email
    validates_length_of :name, :in => 5..30
  end

  company = Company.create(:address => '123 First St.')
  company.errors.on(:name)      # => ["is too short (minimum is 5 characters)", "can't be blank"]
  company.errors.on(:email)     # => "can't be blank"
  company.errors.on(:address)   # => nil

Show source

# File activerecord/lib/active_record/validations.rb, line 212
    def on(attribute)
      attribute = attribute.to_s
      return nil unless @errors.has_key?(attribute)
      errors = @errors[attribute].map(&:to_s)
      errors.size == 1 ? errors.first : errors
    end

August 8, 2014 - (v3.0.0 - v4.0.2)

0 thanks

Deprecated in favour of []

In Rails 3+

company.errors[:name]

In Rails 2.3 and below:

company.errors.on(:name)

on

Related methods

Deprecated in favour of []