Inflector support for acronyms (Issue #1366)

activesupport/lib/active_support/core_ext/string/inflections.rb

@@ -1,5 +1,4 @@
 require 'active_support/inflector/methods'
-require 'active_support/inflector/inflections'
 require 'active_support/inflector/transliterate'
 
 # String inflections define new methods on the String class to transform names for different purposes.

activesupport/lib/active_support/inflector/inflections.rb

@@ -20,10 +20,61 @@ def self.instance
         @__instance__ ||= new
       end
 
-      attr_reader :plurals, :singulars, :uncountables, :humans
+      attr_reader :plurals, :singulars, :uncountables, :humans, :acronyms, :acronym_regex
 
       def initialize
-        @plurals, @singulars, @uncountables, @humans = [], [], [], []
+        @plurals, @singulars, @uncountables, @humans, @acronyms, @acronym_regex = [], [], [], [], {}, /(?=a)b/
+      end
+
+      # Specifies a new acronym. An acronym must be specified as it will appear in a camelized string.  An underscore
+      # string that contains the acronym will retain the acronym when passed to `camelize`, `humanize`, or `titleize`.
+      # A camelized string that contains the acronym will maintain the acronym when titleized or humanized, and will
+      # convert the acronym into a non-delimited single lowercase word when passed to +underscore+.
+      #
+      # Examples:
+      #   acronym 'HTML'
+      #   titleize 'html' #=> 'HTML'
+      #   camelize 'html' #=> 'HTML'
+      #   underscore 'MyHTML' #=> 'my_html'
+      #
+      # The acronym, however, must occur as a delimited unit and not be part of another word for conversions to recognize it:
+      #
+      #   acronym 'HTTP'
+      #   camelize 'my_http_delimited' #=> 'MyHTTPDelimited'
+      #   camelize 'https' #=> 'Https', not 'HTTPs'
+      #   underscore 'HTTPS' #=> 'http_s', not 'https'
+      #
+      #   acronym 'HTTPS'
+      #   camelize 'https' #=> 'HTTPS'
+      #   underscore 'HTTPS' #=> 'https'
+      #
+      # Note: Acronyms that are passed to `pluralize` will no longer be recognized, since the acronym will not occur as
+      # a delimited unit in the pluralized result. To work around this, you must specify the pluralized form as an
+      # acronym as well:
+      #
+      #    acronym 'API'
+      #    camelize(pluralize('api')) #=> 'Apis'
+      #
+      #    acronym 'APIs'
+      #    camelize(pluralize('api')) #=> 'APIs'
+      #
+      # `acronym` may be used to specify any word that contains an acronym or otherwise needs to maintain a non-standard
+      # capitalization. The only restriction is that the word must begin with a capital letter.
+      #
+      # Examples:
+      #   acronym 'RESTful'
+      #   underscore 'RESTful' #=> 'restful'
+      #   underscore 'RESTfulController' #=> 'restful_controller'
+      #   titleize 'RESTfulController' #=> 'RESTful Controller'
+      #   camelize 'restful' #=> 'RESTful'
+      #   camelize 'restful_controller' #=> 'RESTfulController'
+      #
+      #   acronym 'McDonald'
+      #   underscore 'McDonald' #=> 'mcdonald'
+      #   camelize 'mcdonald' #=> 'McDonald'
+      def acronym(word)
+        @acronyms[word.downcase] = word
+        @acronym_regex = /#{@acronyms.values.join("|")}/
       end
 
       # Specifies a new pluralization rule and its replacement. The rule can either be a string or a regular expression.
@@ -117,95 +168,5 @@ def inflections
         Inflections.instance
       end
     end
-
-    # 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)
-      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
-
-    # 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)
-      result = word.to_s.dup
-
-      if inflections.uncountables.any? { |inflection| result =~ /\b(#{inflection})\Z/i }
-        result
-      else
-        inflections.singulars.each { |(rule, replacement)| break if result.gsub!(rule, replacement) }
-        result
-      end
-    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$/, "").gsub(/_/, " ").capitalize
-    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"
-    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
   end
 end

activesupport/lib/active_support/inflector/methods.rb

@@ -1,3 +1,5 @@
+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
@@ -10,6 +12,44 @@ module ActiveSupport
   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)
+      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
+
+    # 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)
+      result = word.to_s.dup
+
+      if inflections.uncountables.any? { |inflection| result =~ /\b(#{inflection})\Z/i }
+        result
+      else
+        inflections.singulars.each { |(rule, replacement)| break if result.gsub!(rule, replacement) }
+        result
+      end
+    end
+
     # By default, +camelize+ converts strings to UpperCamelCase. If the argument to +camelize+
     # is set to <tt>:lower</tt> then +camelize+ produces lowerCamelCase.
     #
@@ -25,12 +65,14 @@ module Inflector
     # 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.
@@ -48,13 +90,66 @@ def camelize(lower_case_and_underscored_word, first_letter_in_uppercase = true)
     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"
+    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: