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
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
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
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
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
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
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
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
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
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
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
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
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
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
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