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rails--rails/activesupport/lib/active_support/inflector.rb

179 lines
5.6 KiB
Ruby

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)$/i, '\1\2en'
# inflect.singular /^(ox)en/i, '\1'
#
# inflect.irregular 'octopus', 'octopi'
#
# inflect.uncountable "equipment"
# end
#
# New rules are added at the top. So in the example above, the irregular rule for octopus will now be the first of the
# pluralization and singularization rules that is runs. This guarantees that your rules run before any of the rules that may
# already have been loaded.
class Inflections
include Singleton
attr_reader :plurals, :singulars, :uncountables
def initialize
@plurals, @singulars, @uncountables = [], [], []
end
# Specifies a new pluralization rule and its replacement. The rule can either be a string or a regular expression.
# The replacement should always be a string that may include references to the matched data from the rule.
def plural(rule, replacement)
@plurals.insert(0, [rule, replacement])
end
# Specifies a new singularization rule and its replacement. The rule can either be a string or a regular expression.
# The replacement should always be a string that may include references to the matched data from the rule.
def singular(rule, replacement)
@singulars.insert(0, [rule, replacement])
end
# Specifies a new irregular that applies to both pluralization and singularization at the same time. This can only be used
# for strings, not regular expressions. You simply pass the irregular in singular and plural form.
#
# Examples:
# irregular 'octopus', 'octopi'
# irregular 'person', 'people'
def irregular(singular, plural)
plural(Regexp.new("(#{singular[0,1]})#{singular[1..-1]}$", "i"), '\1' + plural[1..-1])
singular(Regexp.new("(#{plural[0,1]})#{plural[1..-1]}$", "i"), '\1' + singular[1..-1])
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
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
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
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
def titleize(word)
humanize(underscore(word)).gsub(/\b([a-z])/) { $1.capitalize }
end
def underscore(camel_cased_word)
camel_cased_word.to_s.gsub(/::/, '/').
gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').
gsub(/([a-z\d])([A-Z])/,'\1_\2').
tr("-", "_").
downcase
end
def dasherize(underscored_word)
underscored_word.gsub(/_/, '-')
end
def humanize(lower_case_and_underscored_word)
lower_case_and_underscored_word.to_s.gsub(/_id$/, "").gsub(/_/, " ").capitalize
end
def demodulize(class_name_in_module)
class_name_in_module.to_s.gsub(/^.*::/, '')
end
def tableize(class_name)
pluralize(underscore(class_name))
end
def classify(table_name)
# strip out any leading schema name
camelize(singularize(table_name.to_s.sub(/.*\./, '')))
end
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
def constantize(camel_cased_word)
raise NameError, "#{camel_cased_word.inspect} is not a valid constant name!" unless
/^(::)?([A-Z]\w*)(::[A-Z]\w*)*$/ =~ camel_cased_word
camel_cased_word = "::#{camel_cased_word}" unless $1
Object.module_eval(camel_cased_word, __FILE__, __LINE__)
end
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'