require 'singleton' # The Inflector transforms words from singular to plural, class names to table names, modularized class names to ones without, # and class names to foreign keys. The default inflections for pluralization, singularization, and uncountable words are kept # in inflections.rb. module Inflector # A singleton instance of this class is yielded by Inflector.inflections, which can then be used to specify additional # inflection rules. Examples: # # Inflector.inflections do |inflect| # inflect.plural /^(ox)$/i, '\1\2en' # inflect.singular /^(ox)en/i, '\1' # # inflect.irregular 'octopus', 'octopi' # # inflect.uncountable "equipment" # end # # New rules are added at the top. So in the example above, the irregular rule for octopus will now be the first of the # pluralization and singularization rules that is runs. This guarantees that your rules run before any of the rules that may # already have been loaded. class Inflections include Singleton attr_reader :plurals, :singulars, :uncountables def initialize @plurals, @singulars, @uncountables = [], [], [] end # Specifies a new pluralization rule and its replacement. The rule can either be a string or a regular expression. # The replacement should always be a string that may include references to the matched data from the rule. def plural(rule, replacement) @plurals.insert(0, [rule, replacement]) end # Specifies a new singularization rule and its replacement. The rule can either be a string or a regular expression. # The replacement should always be a string that may include references to the matched data from the rule. def singular(rule, replacement) @singulars.insert(0, [rule, replacement]) end # Specifies a new irregular that applies to both pluralization and singularization at the same time. This can only be used # for strings, not regular expressions. You simply pass the irregular in singular and plural form. # # Examples: # irregular 'octopus', 'octopi' # irregular 'person', 'people' def irregular(singular, plural) if singular[0,1].upcase == plural[0,1].upcase plural(Regexp.new("(#{singular[0,1]})#{singular[1..-1]}$", "i"), '\1' + plural[1..-1]) singular(Regexp.new("(#{plural[0,1]})#{plural[1..-1]}$", "i"), '\1' + singular[1..-1]) else plural(Regexp.new("#{singular[0,1].upcase}(?i)#{singular[1..-1]}$"), plural[0,1].upcase + plural[1..-1]) plural(Regexp.new("#{singular[0,1].downcase}(?i)#{singular[1..-1]}$"), plural[0,1].downcase + plural[1..-1]) singular(Regexp.new("#{plural[0,1].upcase}(?i)#{plural[1..-1]}$"), singular[0,1].upcase + singular[1..-1]) singular(Regexp.new("#{plural[0,1].downcase}(?i)#{plural[1..-1]}$"), singular[0,1].downcase + singular[1..-1]) end end # Add uncountable words that shouldn't be attempted inflected. # # Examples: # uncountable "money" # uncountable "money", "information" # uncountable %w( money information rice ) def uncountable(*words) (@uncountables << words).flatten! end # 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 # # Examples: # clear :all # clear :plurals def clear(scope = :all) case scope when :all @plurals, @singulars, @uncountables = [], [], [] else instance_variable_set "@#{scope}", [] end end end extend self def inflections if block_given? yield Inflections.instance else Inflections.instance end end # Returns the plural form of the word in the string. # # Examples # "post".pluralize #=> "posts" # "octopus".pluralize #=> "octopi" # "sheep".pluralize #=> "sheep" # "words".pluralize #=> "words" # "the blue mailman".pluralize #=> "the blue mailmen" # "CamelOctopus".pluralize #=> "CamelOctopi" def pluralize(word) result = word.to_s.dup if inflections.uncountables.include?(result.downcase) result else inflections.plurals.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } result end end # The reverse of pluralize, returns the singular form of a word in a string. # # Examples # "posts".singularize #=> "post" # "octopi".singularize #=> "octopus" # "sheep".singluarize #=> "sheep" # "word".singluarize #=> "word" # "the blue mailmen".singularize #=> "the blue mailman" # "CamelOctopi".singularize #=> "CamelOctopus" def singularize(word) result = word.to_s.dup if inflections.uncountables.include?(result.downcase) result else inflections.singulars.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } result end end # By default, camelize converts strings to UpperCamelCase. If the argument to camelize # is set to ":lower" then camelize produces lowerCamelCase. # # camelize will also convert '/' to '::' which is useful for converting paths to namespaces # # Examples # "active_record".camelize #=> "ActiveRecord" # "active_record".camelize(:lower) #=> "activeRecord" # "active_record/errors".camelize #=> "ActiveRecord::Errors" # "active_record/errors".camelize(:lower) #=> "activeRecord::Errors" def camelize(lower_case_and_underscored_word, first_letter_in_uppercase = true) if first_letter_in_uppercase lower_case_and_underscored_word.to_s.gsub(/\/(.?)/) { "::" + $1.upcase }.gsub(/(^|_)(.)/) { $2.upcase } else lower_case_and_underscored_word.first + camelize(lower_case_and_underscored_word)[1..-1] end end # Capitalizes all the words and replaces some characters in the string to create # a nicer looking title. Titleize is meant for creating pretty output. It is not # used in the Rails internals. # # titleize is also aliased as as titlecase # # Examples # "man from the boondocks".titleize #=> "Man From The Boondocks" # "x-men: the last stand".titleize #=> "X Men: The Last Stand" def titleize(word) humanize(underscore(word)).gsub(/\b([a-z])/) { $1.capitalize } end # The reverse of +camelize+. Makes an underscored form from the expression in the string. # # Changes '::' to '/' to convert namespaces to paths. # # Examples # "ActiveRecord".underscore #=> "active_record" # "ActiveRecord::Errors".underscore #=> active_record/errors def underscore(camel_cased_word) camel_cased_word.to_s.gsub(/::/, '/'). gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2'). gsub(/([a-z\d])([A-Z])/,'\1_\2'). tr("-", "_"). downcase end # Replaces underscores with dashes in the string. # # Example # "puni_puni" #=> "puni-puni" def dasherize(underscored_word) underscored_word.gsub(/_/, '-') end # Capitalizes the first word and turns underscores into spaces and strips _id. # Like titleize, this is meant for creating pretty output. # # Examples # "employee_salary" #=> "Employee salary" # "author_id" #=> "Author" def humanize(lower_case_and_underscored_word) lower_case_and_underscored_word.to_s.gsub(/_id$/, "").gsub(/_/, " ").capitalize end # Removes the module part from the expression in the string # # Examples # "ActiveRecord::CoreExtensions::String::Inflections".demodulize #=> "Inflections" # "Inflections".demodulize #=> "Inflections" def demodulize(class_name_in_module) class_name_in_module.to_s.gsub(/^.*::/, '') end # Create the name of a table like Rails does for models to table names. This method # uses the pluralize method on the last word in the string. # # Examples # "RawScaledScorer".tableize #=> "raw_scaled_scorers" # "egg_and_ham".tableize #=> "egg_and_hams" # "fancyCategory".tableize #=> "fancy_categories" def tableize(class_name) pluralize(underscore(class_name)) end # Create a class name from a table name like Rails does for table names to models. # Note that this returns a string and not a Class. (To convert to an actual class # follow classify with constantize.) # # Examples # "egg_and_hams".classify #=> "EggAndHam" # "post".classify #=> "Post" def classify(table_name) # strip out any leading schema name camelize(singularize(table_name.to_s.sub(/.*\./, ''))) end # Creates a foreign key name from a class name. # +separate_class_name_and_id_with_underscore+ sets whether # the method should put '_' between the name and 'id'. # # Examples # "Message".foreign_key #=> "message_id" # "Message".foreign_key(false) #=> "messageid" # "Admin::Post".foreign_key #=> "post_id" def foreign_key(class_name, separate_class_name_and_id_with_underscore = true) underscore(demodulize(class_name)) + (separate_class_name_and_id_with_underscore ? "_id" : "id") end # Constantize tries to find a declared constant with the name specified # in the string. It raises a NameError when the name is not in CamelCase # or is not initialized. # # Examples # "Module".constantize #=> Module # "Class".constantize #=> Class def constantize(camel_cased_word) unless /\A(?:::)?([A-Z]\w*(?:::[A-Z]\w*)*)\z/ =~ camel_cased_word raise NameError, "#{camel_cased_word.inspect} is not a valid constant name!" end Object.module_eval("::#{$1}", __FILE__, __LINE__) end # Ordinalize turns a number into an ordinal string used to denote the # position in an ordered sequence such as 1st, 2nd, 3rd, 4th. # # Examples # ordinalize(1) # => "1st" # ordinalize(2) # => "2nd" # ordinalize(1002) # => "1002nd" # ordinalize(1003) # => "1003rd" def ordinalize(number) if (11..13).include?(number.to_i % 100) "#{number}th" else case number.to_i % 10 when 1: "#{number}st" when 2: "#{number}nd" when 3: "#{number}rd" else "#{number}th" end end end end require File.dirname(__FILE__) + '/inflections'