Active Record validation is reported to and from this object, which is used by Base#save to determine whether the object in a valid state to be saved. See usage example in Validations.

Methods
Included Modules
Public Instance methods
[](attribute)

Alias for on

add(attribute, msg = @@default_error_messages[:invalid])

Adds an error message (msg) to the attribute, which will be returned on a call to on(attribute) for the same attribute and ensure that this error object returns false when asked if empty?. More than one error can be added to the same attribute in which case an array will be returned on a call to on(attribute). If no msg is supplied, "invalid" is assumed.

    # File vendor/rails/activerecord/lib/active_record/validations.rb, line 57
57:     def add(attribute, msg = @@default_error_messages[:invalid])
58:       @errors[attribute.to_s] = [] if @errors[attribute.to_s].nil?
59:       @errors[attribute.to_s] << msg
60:     end
add_on_blank(attributes, msg = @@default_error_messages[:blank])

Will add an error message to each of the attributes in attributes that is blank (using Object#blank?).

    # File vendor/rails/activerecord/lib/active_record/validations.rb, line 72
72:     def add_on_blank(attributes, msg = @@default_error_messages[:blank])
73:       for attr in [attributes].flatten
74:         value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s]
75:         add(attr, msg) if value.blank?
76:       end
77:     end
add_on_boundary_breaking(attributes, range, too_long_msg = @@default_error_messages[:too_long], too_short_msg = @@default_error_messages[:too_short])

Will add an error message to each of the attributes in attributes that has a length outside of the passed boundary range. If the length is above the boundary, the too_long_msg message will be used. If below, the too_short_msg.

This method is also aliased as add_on_boundry_breaking
    # File vendor/rails/activerecord/lib/active_record/validations.rb, line 81
81:     def add_on_boundary_breaking(attributes, range, too_long_msg = @@default_error_messages[:too_long], too_short_msg = @@default_error_messages[:too_short])
82:       for attr in [attributes].flatten
83:         value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s]
84:         add(attr, too_short_msg % range.begin) if value && value.length < range.begin
85:         add(attr, too_long_msg % range.end) if value && value.length > range.end
86:       end
87:     end
add_on_boundry_breaking(attributes, range, too_long_msg = @@default_error_messages[:too_long], too_short_msg = @@default_error_messages[:too_short])
add_on_empty(attributes, msg = @@default_error_messages[:empty])

Will add an error message to each of the attributes in attributes that is empty.

    # File vendor/rails/activerecord/lib/active_record/validations.rb, line 63
63:     def add_on_empty(attributes, msg = @@default_error_messages[:empty])
64:       for attr in [attributes].flatten
65:         value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s]
66:         is_empty = value.respond_to?("empty?") ? value.empty? : false
67:         add(attr, msg) unless !value.nil? && !is_empty
68:       end
69:     end
add_to_base(msg)

Adds an error to the base object instead of any particular attribute. This is used to report errors that don‘t tie to any specific attribute, but rather to the object as a whole. These error messages don‘t get prepended with any field name when iterating with each_full, so they should be complete sentences.

    # File vendor/rails/activerecord/lib/active_record/validations.rb, line 49
49:     def add_to_base(msg)
50:       add(:base, msg)
51:     end
clear()

Removes all the errors that have been added.

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 148
148:     def clear
149:       @errors = {}
150:     end
count()

Alias for size

each() {|attr, msg| ...}

Yields each attribute and associated message per error added.

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 114
114:     def each
115:       @errors.each_key { |attr| @errors[attr].each { |msg| yield attr, msg } }
116:     end
each_full() {|msg| ...}

Yields each full error message added. So Person.errors.add("first_name", "can‘t be empty") will be returned through iteration as "First name can‘t be empty".

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 120
120:     def each_full
121:       full_messages.each { |msg| yield msg }
122:     end
empty?()

Returns true if no errors have been added.

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 143
143:     def empty?
144:       @errors.empty?
145:     end
full_messages()

Returns all the full error messages in an array.

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 125
125:     def full_messages
126:       full_messages = []
127: 
128:       @errors.each_key do |attr|
129:         @errors[attr].each do |msg|
130:           next if msg.nil?
131: 
132:           if attr == "base"
133:             full_messages << msg
134:           else
135:             full_messages << @base.class.human_attribute_name(attr) + " " + msg
136:           end
137:         end
138:       end
139:       full_messages
140:     end
invalid?(attribute)

Returns true if the specified attribute has errors associated with it.

    # File vendor/rails/activerecord/lib/active_record/validations.rb, line 93
93:     def invalid?(attribute)
94:       !@errors[attribute.to_s].nil?
95:     end
length()

Alias for size

on(attribute)
  • 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.
This method is also aliased as []
     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 100
100:     def on(attribute)
101:       errors = @errors[attribute.to_s]
102:       return nil if errors.nil?
103:       errors.size == 1 ? errors.first : errors
104:     end
on_base()

Returns errors assigned to base object through add_to_base according to the normal rules of on(attribute).

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 109
109:     def on_base
110:       on(:base)
111:     end
size()

Returns the total number of errors added. Two errors added to the same attribute will be counted as such with this as well.

This method is also aliased as count length
     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 154
154:     def size
155:       @errors.values.inject(0) { |error_count, attribute| error_count + attribute.size }
156:     end
to_xml(options={})

Return an XML representation of this error object.

     # File vendor/rails/activerecord/lib/active_record/validations.rb, line 162
162:     def to_xml(options={})
163:       options[:root] ||= "errors"
164:       options[:indent] ||= 2
165:       options[:builder] ||= Builder::XmlMarkup.new(:indent => options[:indent])
166: 
167:       options[:builder].instruct! unless options.delete(:skip_instruct)
168:       options[:builder].errors do |e|
169:         full_messages.each { |msg| e.error(msg) }
170:       end
171:     end