require 'active_support/inflector/inflections' module ActiveSupport # 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. # # The Rails core team has stated patches for the inflections library will not be accepted # in order to avoid breaking legacy applications which may be relying on errant inflections. # If you discover an incorrect inflection and require it for your application, you'll need # to correct it yourself (explained below). module Inflector extend self # Returns the plural form of the word in the string. # # Examples: # "post".pluralize # => "posts" # "octopus".pluralize # => "octopi" # "sheep".pluralize # => "sheep" # "words".pluralize # => "words" # "CamelOctopus".pluralize # => "CamelOctopi" def pluralize(word) apply_inflections(word, inflections.plurals) end # The reverse of +pluralize+, returns the singular form of a word in a string. # # Examples: # "posts".singularize # => "post" # "octopi".singularize # => "octopus" # "sheep".singularize # => "sheep" # "word".singularize # => "word" # "CamelOctopi".singularize # => "CamelOctopus" def singularize(word) apply_inflections(word, inflections.singulars) 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_model".camelize # => "ActiveModel" # "active_model".camelize(:lower) # => "activeModel" # "active_model/errors".camelize # => "ActiveModel::Errors" # "active_model/errors".camelize(:lower) # => "activeModel::Errors" # # As a rule of thumb you can think of +camelize+ as the inverse of +underscore+, # though there are cases where that does not hold: # # "SSLError".underscore.camelize # => "SslError" def camelize(term, uppercase_first_letter = true) string = term.to_s if uppercase_first_letter string = string.sub(/^[a-z\d]*/) { inflections.acronyms[$&] || $&.capitalize } else string = string.sub(/^(?:#{inflections.acronym_regex}(?=\b|[A-Z_])|\w)/) { $&.downcase } end string.gsub(/(?:_|(\/))([a-z\d]*)/i) { "#{$1}#{inflections.acronyms[$2] || $2.capitalize}" }.gsub('/', '::') end # Makes an underscored, lowercase form from the expression in the string. # # Changes '::' to '/' to convert namespaces to paths. # # Examples: # "ActiveModel".underscore # => "active_model" # "ActiveModel::Errors".underscore # => "active_model/errors" # # As a rule of thumb you can think of +underscore+ as the inverse of +camelize+, # though there are cases where that does not hold: # # "SSLError".underscore.camelize # => "SslError" def underscore(camel_cased_word) word = camel_cased_word.to_s.dup word.gsub!(/::/, '/') word.gsub!(/(?:([A-Za-z\d])|^)(#{inflections.acronym_regex})(?=\b|[^a-z])/) { "#{$1}#{$1 && '_'}#{$2.downcase}" } word.gsub!(/([A-Z\d]+)([A-Z][a-z])/,'\1_\2') word.gsub!(/([a-z\d])([A-Z])/,'\1_\2') word.tr!("-", "_") word.downcase! word end # Capitalizes the first word and turns underscores into spaces and strips a # trailing "_id", if any. Like +titleize+, this is meant for creating pretty output. # # Examples: # "employee_salary" # => "Employee salary" # "author_id" # => "Author" def humanize(lower_case_and_underscored_word) result = lower_case_and_underscored_word.to_s.dup inflections.humans.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } result.gsub!(/_id$/, "") result.gsub!(/_/, ' ') result.gsub(/([a-z\d]*)/i) { |match| "#{inflections.acronyms[match] || match.downcase}" }.gsub(/^\w/) { $&.upcase } 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" # "TheManWithoutAPast".titleize # => "The Man Without A Past" # "raiders_of_the_lost_ark".titleize # => "Raiders Of The Lost Ark" def titleize(word) humanize(underscore(word)).gsub(/\b('?[a-z])/) { $1.capitalize } 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 plural 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" # "posts".classify # => "Post" # # Singular names are not handled correctly: # "business".classify # => "Busines" def classify(table_name) # strip out any leading schema name camelize(singularize(table_name.to_s.sub(/.*\./, ''))) end # Replaces underscores with dashes in the string. # # Example: # "puni_puni" # => "puni-puni" def dasherize(underscored_word) underscored_word.gsub(/_/, '-') end # Removes the module part from the expression in the string: # # "ActiveRecord::CoreExtensions::String::Inflections".demodulize # => "Inflections" # "Inflections".demodulize # => "Inflections" # # See also +deconstantize+. def demodulize(path) path = path.to_s if i = path.rindex('::') path[(i+2)..-1] else path end end # Removes the rightmost segment from the constant expression in the string: # # "Net::HTTP".deconstantize # => "Net" # "::Net::HTTP".deconstantize # => "::Net" # "String".deconstantize # => "" # "::String".deconstantize # => "" # "".deconstantize # => "" # # See also +demodulize+. def deconstantize(path) path.to_s[0...(path.rindex('::') || 0)] # implementation based on the one in facets' Module#spacename 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 # Tries to find a constant with the name specified in the argument string: # # "Module".constantize # => Module # "Test::Unit".constantize # => Test::Unit # # The name is assumed to be the one of a top-level constant, no matter whether # it starts with "::" or not. No lexical context is taken into account: # # C = 'outside' # module M # C = 'inside' # C # => 'inside' # "C".constantize # => 'outside', same as ::C # end # # NameError is raised when the name is not in CamelCase or the constant is # unknown. def constantize(camel_cased_word) #:nodoc: names = camel_cased_word.split('::') names.shift if names.empty? || names.first.empty? constant = Object names.each do |name| constant = constant.const_get(name, false) end constant end # Tries to find a constant with the name specified in the argument string: # # "Module".safe_constantize # => Module # "Test::Unit".safe_constantize # => Test::Unit # # The name is assumed to be the one of a top-level constant, no matter whether # it starts with "::" or not. No lexical context is taken into account: # # C = 'outside' # module M # C = 'inside' # C # => 'inside' # "C".safe_constantize # => 'outside', same as ::C # end # # nil is returned when the name is not in CamelCase or the constant (or part of it) is # unknown. # # "blargle".safe_constantize # => nil # "UnknownModule".safe_constantize # => nil # "UnknownModule::Foo::Bar".safe_constantize # => nil # def safe_constantize(camel_cased_word) begin constantize(camel_cased_word) rescue NameError => e raise unless e.message =~ /(uninitialized constant|wrong constant name) #{const_regexp(camel_cased_word)}$/ || e.name.to_s == camel_cased_word.to_s rescue ArgumentError => e raise unless e.message =~ /not missing constant #{const_regexp(camel_cased_word)}\!$/ end end # 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" # ordinalize(-11) # => "-11th" # ordinalize(-1021) # => "-1021st" def ordinalize(number) if (11..13).include?(number.to_i.abs % 100) "#{number}th" else case number.to_i.abs % 10 when 1; "#{number}st" when 2; "#{number}nd" when 3; "#{number}rd" else "#{number}th" end end end private # Mount a regular expression that will match part by part of the constant. # For instance, Foo::Bar::Baz will generate Foo(::Bar(::Baz)?)? def const_regexp(camel_cased_word) #:nodoc: parts = camel_cased_word.split("::") last = parts.pop parts.reverse.inject(last) do |acc, part| part.empty? ? acc : "#{part}(::#{acc})?" end end # Applies inflection rules for +singularize+ and +pluralize+. # # Examples: # apply_inflections("post", inflections.plurals) # => "posts" # apply_inflections("posts", inflections.singulars) # => "post" def apply_inflections(word, rules) result = word.to_s.dup if word.empty? || inflections.uncountables.any? { |inflection| result =~ /\b#{inflection}\Z/i } result else rules.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } result end end end end