methods.rb in activesupport-3.2.0.rc1

- old
+ new

@@ -1,5 +1,7 @@
+require 'active_support/inflector/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.
   #
@@ -8,10 +10,34 @@
   # 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.
     #
@@ -23,16 +49,18 @@
     #
     # 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(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(/(?:^|_)(.)/) { $1.upcase }
+    def camelize(term, uppercase_first_letter = true)
+      string = term.to_s
+      if uppercase_first_letter
+        string = string.sub(/^[a-z\d]*/) { inflections.acronyms[$&] || $&.capitalize }
       else
-        lower_case_and_underscored_word.to_s[0].chr.downcase + camelize(lower_case_and_underscored_word)[1..-1]
+        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.
@@ -46,34 +74,108 @@
     #
     #   "SSLError".underscore.camelize # => "SslError"
     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-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(/(_)?([a-z\d]*)/i) { "#{$1 && ' '}#{inflections.acronyms[$2] || $2.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.
+    # 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(/^.*::/, '')
+    #
+    # 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:
@@ -125,10 +227,43 @@
         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 #{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"
@@ -145,9 +280,38 @@
           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