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
# 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_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(/(?:^|_)(.)/) { $1.upcase }
else
lower_case_and_underscored_word.to_s[0].chr.downcase + camelize(lower_case_and_underscored_word)[1..-1]
end
end
# The reverse of +camelize+. Makes an underscored, lowercase 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
# 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
# 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_get(name, false) || constant.const_missing(name)
end
constant
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"
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
end
