module Poro::Util::Inflector

License

Inflector is from AcitveSupport, which is distributed via the following MIT license:

Copyright © 2005-2010 David Heinemeier Hansson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Overview

This module contains the inflector from ActiveSupport, but in its own namespace and without being injected into the String class. This prevents Poro’s implementation from clobbering that of ActiveSupport, should the rest of your project be using it, even if you include ActiveSupport before Poro.

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).

Public Instance Methods

camelize(lower_case_and_underscored_word, first_letter_in_uppercase = true) click to toggle source

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"

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"
# File lib/poro/util/inflector/methods.rb, line 29
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
classify(table_name) click to toggle source

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"
# File lib/poro/util/inflector/inflections.rb, line 207
def classify(table_name)
  # strip out any leading schema name
  camelize(singularize(table_name.to_s.sub(/.*\./, '')))
end
constantize(camel_cased_word) click to toggle source

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.

# File lib/poro/util/inflector/methods.rb, line 108
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
dasherize(underscored_word) click to toggle source

Replaces underscores with dashes in the string.

Example:

"puni_puni" # => "puni-puni"
# File lib/poro/util/inflector/methods.rb, line 63
def dasherize(underscored_word)
  underscored_word.gsub(/_/, '-')
end
demodulize(class_name_in_module) click to toggle source

Removes the module part from the expression in the string.

Examples:

"ActiveRecord::CoreExtensions::String::Inflections".demodulize # => "Inflections"
"Inflections".demodulize                                       # => "Inflections"
# File lib/poro/util/inflector/methods.rb, line 72
def demodulize(class_name_in_module)
  class_name_in_module.to_s.gsub(/^.*::/, '')
end
foreign_key(class_name, separate_class_name_and_id_with_underscore = true) click to toggle source

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"
# File lib/poro/util/inflector/methods.rb, line 84
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
humanize(lower_case_and_underscored_word) click to toggle source

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"
# File lib/poro/util/inflector/inflections.rb, line 166
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$/, "").gsub(/_/, " ").capitalize
end
inflections() { |instance| ... } click to toggle source

Yields a singleton instance of Inflector::Inflections so you can specify additional inflector rules.

Example:

ActiveSupport::Inflector.inflections do |inflect|
  inflect.uncountable "rails"
end
# File lib/poro/util/inflector/inflections.rb, line 114
def inflections
  if block_given?
    yield Inflections.instance
  else
    Inflections.instance
  end
end
ordinalize(number) click to toggle source

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"
# File lib/poro/util/inflector/methods.rb, line 139
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
pluralize(word) click to toggle source

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"
# File lib/poro/util/inflector/inflections.rb, line 130
def pluralize(word)
  result = word.to_s.dup

  if word.empty? || inflections.uncountables.include?(result.downcase)
    result
  else
    inflections.plurals.each { |(rule, replacement)| break if result.gsub!(rule, replacement) }
    result
  end
end
singularize(word) click to toggle source

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"
# File lib/poro/util/inflector/inflections.rb, line 149
def singularize(word)
  result = word.to_s.dup

  if inflections.uncountables.any? { |inflection| result =~ /#{inflection}\Z/i }
    result
  else
    inflections.singulars.each { |(rule, replacement)| break if result.gsub!(rule, replacement) }
    result
  end
end
tableize(class_name) click to toggle source

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"
# File lib/poro/util/inflector/inflections.rb, line 193
def tableize(class_name)
  pluralize(underscore(class_name))
end
titleize(word) click to toggle source

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"
# File lib/poro/util/inflector/inflections.rb, line 182
def titleize(word)
  humanize(underscore(word)).gsub(/\b('?[a-z])/) { $1.capitalize }
end
underscore(camel_cased_word) click to toggle source

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

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"
# File lib/poro/util/inflector/methods.rb, line 49
def underscore(camel_cased_word)
  word = camel_cased_word.to_s.dup
  word.gsub!(/::/, '/')
  word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
  word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
  word.tr!("-", "_")
  word.downcase!
  word
end