/activesupport/lib/active_support/inflector/methods.rb
Ruby | 321 lines | 169 code | 18 blank | 134 comment | 15 complexity | 8bf55fe0ed5168ba560f52333c75d2be MD5 | raw file
- require 'active_support/inflector/inflections'
- require 'active_support/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 <tt>:lower</tt> 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
- # Ruby 1.9 introduces an inherit argument for Module#const_get and
- # #const_defined? and changes their default behavior.
- if Module.method(:const_get).arity == 1
- # 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)
- names = camel_cased_word.split('::')
- names.shift if names.empty? || names.first.empty?
- constant = Object
- names.each do |name|
- constant = constant.const_defined?(name) ? constant.const_get(name) : constant.const_missing(name)
- end
- constant
- end
- else
- 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_defined?(name, false) ? constant.const_get(name) : constant.const_missing(name)
- end
- constant
- end
- 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