Module | ActiveSupport::Inflector |
In: |
vendor/rails/activesupport/lib/active_support/inflector.rb
|
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).
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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 178 178: def camelize(lower_case_and_underscored_word, first_letter_in_uppercase = true) 179: if first_letter_in_uppercase 180: lower_case_and_underscored_word.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase } 181: else 182: lower_case_and_underscored_word.first.downcase + camelize(lower_case_and_underscored_word)[1..-1] 183: end 184: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 318 318: def classify(table_name) 319: # strip out any leading schema name 320: camelize(singularize(table_name.to_s.sub(/.*\./, ''))) 321: end
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 vendor/rails/activesupport/lib/active_support/inflector.rb, line 355 355: def constantize(camel_cased_word) 356: names = camel_cased_word.split('::') 357: names.shift if names.empty? || names.first.empty? 358: 359: constant = Object 360: names.each do |name| 361: constant = constant.const_defined?(name) ? constant.const_get(name) : constant.const_missing(name) 362: end 363: constant 364: end
Replaces underscores with dashes in the string.
Example:
"puni_puni" # => "puni-puni"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 218 218: def dasherize(underscored_word) 219: underscored_word.gsub(/_/, '-') 220: end
Removes the module part from the expression in the string.
Examples:
"ActiveRecord::CoreExtensions::String::Inflections".demodulize # => "Inflections" "Inflections".demodulize # => "Inflections"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 240 240: def demodulize(class_name_in_module) 241: class_name_in_module.to_s.gsub(/^.*::/, '') 242: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 331 331: def foreign_key(class_name, separate_class_name_and_id_with_underscore = true) 332: underscore(demodulize(class_name)) + (separate_class_name_and_id_with_underscore ? "_id" : "id") 333: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 228 228: def humanize(lower_case_and_underscored_word) 229: result = lower_case_and_underscored_word.to_s.dup 230: 231: inflections.humans.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } 232: result.gsub(/_id$/, "").gsub(/_/, " ").capitalize 233: end
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 vendor/rails/activesupport/lib/active_support/inflector.rb, line 122 122: def inflections 123: if block_given? 124: yield Inflections.instance 125: else 126: Inflections.instance 127: end 128: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 386 386: def ordinalize(number) 387: if (11..13).include?(number.to_i % 100) 388: "#{number}th" 389: else 390: case number.to_i % 10 391: when 1; "#{number}st" 392: when 2; "#{number}nd" 393: when 3; "#{number}rd" 394: else "#{number}th" 395: end 396: end 397: end
Replaces special characters in a string so that it may be used as part of a ‘pretty’ URL.
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(@person)) %> # => <a href="/person/1-donald-e-knuth">Donald E. Knuth</a>
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 259 259: def parameterize(string, sep = '-') 260: # replace accented chars with ther ascii equivalents 261: parameterized_string = transliterate(string) 262: # Turn unwanted chars into the seperator 263: parameterized_string.gsub!(/[^a-z0-9\-_\+]+/i, sep) 264: unless sep.blank? 265: re_sep = Regexp.escape(sep) 266: # No more than one of the separator in a row. 267: parameterized_string.gsub!(/#{re_sep}{2,}/, sep) 268: # Remove leading/trailing separator. 269: parameterized_string.gsub!(/^#{re_sep}|#{re_sep}$/i, '') 270: end 271: parameterized_string.downcase 272: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 138 138: def pluralize(word) 139: result = word.to_s.dup 140: 141: if word.empty? || inflections.uncountables.include?(result.downcase) 142: result 143: else 144: inflections.plurals.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } 145: result 146: end 147: end
The reverse of pluralize, returns the singular form of a word in a string.
Examples:
"posts".singularize # => "post" "octopi".singularize # => "octopus" "sheep".singluarize # => "sheep" "word".singularize # => "word" "CamelOctopi".singularize # => "CamelOctopus"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 157 157: def singularize(word) 158: result = word.to_s.dup 159: 160: if inflections.uncountables.include?(result.downcase) 161: result 162: else 163: inflections.singulars.each { |(rule, replacement)| break if result.gsub!(rule, replacement) } 164: result 165: end 166: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 304 304: def tableize(class_name) 305: pluralize(underscore(class_name)) 306: 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"
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 195 195: def titleize(word) 196: humanize(underscore(word)).gsub(/\b('?[a-z])/) { $1.capitalize } 197: end
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 291 291: def transliterate(string) 292: string.mb_chars.normalize(:kd). # Decompose accented characters 293: gsub(/[^\x00-\x7F]+/, '') # Remove anything non-ASCII entirely (e.g. diacritics). 294: end
Replaces accented characters with their ascii equivalents.
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 276 276: def transliterate(string) 277: Iconv.iconv('ascii//ignore//translit', 'utf-8', string).to_s 278: end
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 282 282: def transliterate(string) 283: warn "Ruby 1.9 doesn't support Unicode normalization yet" 284: string.dup 285: 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
# File vendor/rails/activesupport/lib/active_support/inflector.rb, line 206 206: def underscore(camel_cased_word) 207: camel_cased_word.to_s.gsub(/::/, '/'). 208: gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2'). 209: gsub(/([a-z\d])([A-Z])/,'\1_\2'). 210: tr("-", "_"). 211: downcase 212: end