path: root/activesupport/lib/active_support/core_ext/string/inflections.rb

require 'active_support/inflector/methods'
require 'active_support/inflector/transliterate'

# String inflections define new methods on the String class to transform names for different purposes.
# For instance, you can figure out the name of a table from the name of a class.
#
#   "ScaleScore".tableize # => "scale_scores"
#
class String
  # Returns the plural form of the word in the string.
  #
  # If the optional parameter +count+ is specified,
  # the singular form will be returned if <tt>count == 1</tt>.
  # For any other value of +count+ the plural will be returned.
  #
  # ==== Examples
  #   "post".pluralize             # => "posts"
  #   "octopus".pluralize          # => "octopi"
  #   "sheep".pluralize            # => "sheep"
  #   "words".pluralize            # => "words"
  #   "the blue mailman".pluralize # => "the blue mailmen"
  #   "CamelOctopus".pluralize     # => "CamelOctopi"
  #   "apple".pluralize(1)         # => "apple"
  #   "apple".pluralize(2)         # => "apples"
  def pluralize(count = nil)
    if count == 1
      self
    else
      ActiveSupport::Inflector.pluralize(self)
    end
  end

  # The reverse of +pluralize+, returns the singular form of a word in a string.
  #
  #   "posts".singularize            # => "post"
  #   "octopi".singularize           # => "octopus"
  #   "sheep".singularize            # => "sheep"
  #   "word".singularize             # => "word"
  #   "the blue mailmen".singularize # => "the blue mailman"
  #   "CamelOctopi".singularize      # => "CamelOctopus"
  def singularize
    ActiveSupport::Inflector.singularize(self)
  end

  # +constantize+ tries to find a declared constant with the name specified
  # in the string. It raises a NameError when the name is not in CamelCase
  # or is not initialized.  See ActiveSupport::Inflector.constantize
  #
  # Examples
  #   "Module".constantize  # => Module
  #   "Class".constantize   # => Class
  #   "blargle".constantize # => NameError: wrong constant name blargle
  def constantize
    ActiveSupport::Inflector.constantize(self)
  end

  # +safe_constantize+ tries to find a declared constant with the name specified
  # in the string. It returns nil when the name is not in CamelCase
  # or is not initialized.  See ActiveSupport::Inflector.safe_constantize
  #
  # Examples
  #   "Module".safe_constantize  # => Module
  #   "Class".safe_constantize   # => Class
  #   "blargle".safe_constantize # => nil
  def safe_constantize
    ActiveSupport::Inflector.safe_constantize(self)
  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.
  #
  #   "active_record".camelize                # => "ActiveRecord"
  #   "active_record".camelize(:lower)        # => "activeRecord"
  #   "active_record/errors".camelize         # => "ActiveRecord::Errors"
  #   "active_record/errors".camelize(:lower) # => "activeRecord::Errors"
  def camelize(first_letter = :upper)
    case first_letter
    when :upper
      ActiveSupport::Inflector.camelize(self, true)
    when :lower
      ActiveSupport::Inflector.camelize(self, false)
    end
  end
  alias_method :camelcase, :camelize

  # 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 +titlecase+.
  #
  #   "man from the boondocks".titleize # => "Man From The Boondocks"
  #   "x-men: the last stand".titleize  # => "X Men: The Last Stand"
  def titleize
    ActiveSupport::Inflector.titleize(self)
  end
  alias_method :titlecase, :titleize

  # The reverse of +camelize+. Makes an underscored, lowercase form from the expression in the string.
  #
  # +underscore+ will also change '::' to '/' to convert namespaces to paths.
  #
  #   "ActiveModel".underscore         # => "active_model"
  #   "ActiveModel::Errors".underscore # => "active_model/errors"
  def underscore
    ActiveSupport::Inflector.underscore(self)
  end

  # Replaces underscores with dashes in the string.
  #
  #   "puni_puni" # => "puni-puni"
  def dasherize
    ActiveSupport::Inflector.dasherize(self)
  end

  # Removes the module part from the constant expression in the string.
  #
  #   "ActiveRecord::CoreExtensions::String::Inflections".demodulize # => "Inflections"
  #   "Inflections".demodulize                                       # => "Inflections"
  #
  # See also +deconstantize+.
  def demodulize
    ActiveSupport::Inflector.demodulize(self)
  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
    ActiveSupport::Inflector.deconstantize(self)
  end

  # Replaces special characters in a string so that it may be used as part of a 'pretty' URL.
  #
  # ==== Examples
  #
  #   class Person
  #     def to_param
  #       "#{id}-#{name.parameterize}"
  #     end
  #   end
  #
  #   @person = Person.find(1)
  #   # => #<Person id: 1, name: "Donald E. Knuth">
  #
  #   <%= link_to(@person.name, person_path %>
  #   # => <a href="/person/1-donald-e-knuth">Donald E. Knuth</a>
  def parameterize(sep = '-')
    ActiveSupport::Inflector.parameterize(self, sep)
  end

  # Creates 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.
  #
  #   "RawScaledScorer".tableize # => "raw_scaled_scorers"
  #   "egg_and_ham".tableize     # => "egg_and_hams"
  #   "fancyCategory".tableize   # => "fancy_categories"
  def tableize
    ActiveSupport::Inflector.tableize(self)
  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+.)
  #
  #   "egg_and_hams".classify # => "EggAndHam"
  #   "posts".classify        # => "Post"
  #
  # Singular names are not handled correctly.
  #
  #   "business".classify # => "Busines"
  def classify
    ActiveSupport::Inflector.classify(self)
  end

  # Capitalizes the first word, turns underscores into spaces, and strips '_id'.
  # Like +titleize+, this is meant for creating pretty output.
  #
  #   "employee_salary" # => "Employee salary"
  #   "author_id"       # => "Author"
  def humanize
    ActiveSupport::Inflector.humanize(self)
  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(separate_class_name_and_id_with_underscore = true)
    ActiveSupport::Inflector.foreign_key(self, separate_class_name_and_id_with_underscore)
  end
end