A singleton instance of this class is yielded by Inflector.inflections, which can then be used to specify additional inflection rules. If passed an optional locale, rules for other languages can be specified. The default locale is :en. Only rules for English are provided.

ActiveSupport::Inflector.inflections(:en) do |inflect|
  inflect.plural /^(ox)$/i, '\1\2en'
  inflect.singular /^(ox)en/i, '\1'

  inflect.irregular 'cactus', 'cacti'

  inflect.uncountable 'equipment'
end

New rules are added at the top. So in the example above, the irregular rule for cactus will now be the first of the pluralization and singularization rules that is runs. This guarantees that your rules run before any of the rules that may already have been loaded.

Namespace

Class

Methods

Attributes

[R] acronyms
[R] humans
[R] plurals
[R] singulars
[R] uncountables

Class Public methods

instance(locale = :en)

# File activesupport/lib/active_support/inflector/inflections.rb, line 63
def self.instance(locale = :en)
  @__instance__[locale] ||= new
end

instance_or_fallback(locale)

# File activesupport/lib/active_support/inflector/inflections.rb, line 67
def self.instance_or_fallback(locale)
  I18n.fallbacks[locale].each do |k|
    return @__instance__[k] if @__instance__.key?(k)
  end
  instance(locale)
end

new()

# File activesupport/lib/active_support/inflector/inflections.rb, line 78
def initialize
  @plurals, @singulars, @uncountables, @humans, @acronyms = [], [], Uncountables.new, [], {}
  define_acronym_regex_patterns
end

Instance Public methods

acronym(word)

Specifies a new acronym. An acronym must be specified as it will appear in a camelized string. An underscore string that contains the acronym will retain the acronym when passed to camelize, humanize, or titleize. A camelized string that contains the acronym will maintain the acronym when titleized or humanized, and will convert the acronym into a non-delimited single lowercase word when passed to underscore.

acronym 'HTML'
titleize 'html'     # => 'HTML'
camelize 'html'     # => 'HTML'
underscore 'MyHTML' # => 'my_html'

The acronym, however, must occur as a delimited unit and not be part of another word for conversions to recognize it:

acronym 'HTTP'
camelize 'my_http_delimited' # => 'MyHTTPDelimited'
camelize 'https'             # => 'Https', not 'HTTPs'
underscore 'HTTPS'           # => 'http_s', not 'https'

acronym 'HTTPS'
camelize 'https'   # => 'HTTPS'
underscore 'HTTPS' # => 'https'

Note: Acronyms that are passed to pluralize will no longer be recognized, since the acronym will not occur as a delimited unit in the pluralized result. To work around this, you must specify the pluralized form as an acronym as well:

acronym 'API'
camelize(pluralize('api')) # => 'Apis'

acronym 'APIs'
camelize(pluralize('api')) # => 'APIs'

acronym may be used to specify any word that contains an acronym or otherwise needs to maintain a non-standard capitalization. The only restriction is that the word must begin with a capital letter.

acronym 'RESTful'
underscore 'RESTful'           # => 'restful'
underscore 'RESTfulController' # => 'restful_controller'
titleize 'RESTfulController'   # => 'RESTful Controller'
camelize 'restful'             # => 'RESTful'
camelize 'restful_controller'  # => 'RESTfulController'

acronym 'McDonald'
underscore 'McDonald' # => 'mcdonald'
camelize 'mcdonald'   # => 'McDonald'
# File activesupport/lib/active_support/inflector/inflections.rb, line 140
def acronym(word)
  @acronyms[word.downcase] = word
  define_acronym_regex_patterns
end

clear(scope = :all)

Clears the loaded inflections within a given scope (default is :all). Give the scope as a symbol of the inflection type, the options are: :plurals, :singulars, :uncountables, :humans.

clear :all
clear :plurals
# File activesupport/lib/active_support/inflector/inflections.rb, line 229
def clear(scope = :all)
  case scope
  when :all
    @plurals, @singulars, @uncountables, @humans = [], [], Uncountables.new, []
  else
    instance_variable_set "@#{scope}", []
  end
end

human(rule, replacement)

Specifies a humanized form of a string by a regular expression rule or by a string mapping. When using a regular expression based replacement, the normal humanize formatting is called after the replacement. When a string is used, the human form should be specified as desired (example: 'The name', not 'the_name').

human /_cnt$/i, '\1_count'
human 'legacy_col_person_name', 'Name'
# File activesupport/lib/active_support/inflector/inflections.rb, line 218
def human(rule, replacement)
  @humans.prepend([rule, replacement])
end

irregular(singular, plural)

Specifies a new irregular that applies to both pluralization and singularization at the same time. This can only be used for strings, not regular expressions. You simply pass the irregular in singular and plural form.

irregular 'cactus', 'cacti'
irregular 'person', 'people'
# File activesupport/lib/active_support/inflector/inflections.rb, line 172
def irregular(singular, plural)
  @uncountables.delete(singular)
  @uncountables.delete(plural)

  s0 = singular[0]
  srest = singular[1..-1]

  p0 = plural[0]
  prest = plural[1..-1]

  if s0.upcase == p0.upcase
    plural(/(#{s0})#{srest}$/i, '\1' + prest)
    plural(/(#{p0})#{prest}$/i, '\1' + prest)

    singular(/(#{s0})#{srest}$/i, '\1' + srest)
    singular(/(#{p0})#{prest}$/i, '\1' + srest)
  else
    plural(/#{s0.upcase}(?i)#{srest}$/,   p0.upcase   + prest)
    plural(/#{s0.downcase}(?i)#{srest}$/, p0.downcase + prest)
    plural(/#{p0.upcase}(?i)#{prest}$/,   p0.upcase   + prest)
    plural(/#{p0.downcase}(?i)#{prest}$/, p0.downcase + prest)

    singular(/#{s0.upcase}(?i)#{srest}$/,   s0.upcase   + srest)
    singular(/#{s0.downcase}(?i)#{srest}$/, s0.downcase + srest)
    singular(/#{p0.upcase}(?i)#{prest}$/,   s0.upcase   + srest)
    singular(/#{p0.downcase}(?i)#{prest}$/, s0.downcase + srest)
  end
end

plural(rule, replacement)

Specifies a new pluralization rule and its replacement. The rule can either be a string or a regular expression. The replacement should always be a string that may include references to the matched data from the rule.

# File activesupport/lib/active_support/inflector/inflections.rb, line 149
def plural(rule, replacement)
  @uncountables.delete(rule) if rule.is_a?(String)
  @uncountables.delete(replacement)
  @plurals.prepend([rule, replacement])
end

singular(rule, replacement)

Specifies a new singularization rule and its replacement. The rule can either be a string or a regular expression. The replacement should always be a string that may include references to the matched data from the rule.

# File activesupport/lib/active_support/inflector/inflections.rb, line 159
def singular(rule, replacement)
  @uncountables.delete(rule) if rule.is_a?(String)
  @uncountables.delete(replacement)
  @singulars.prepend([rule, replacement])
end

uncountable(*words)

Specifies words that are uncountable and should not be inflected.

uncountable 'money'
uncountable 'money', 'information'
uncountable %w( money information rice )
# File activesupport/lib/active_support/inflector/inflections.rb, line 206
def uncountable(*words)
  @uncountables.add(words)
end