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390 lines
14 KiB
Ruby
390 lines
14 KiB
Ruby
require 'active_support/inflections'
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module ActiveSupport
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# The Inflector transforms words from singular to plural, class names to table
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# names, modularized class names to ones without, and class names to foreign
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# keys. The default inflections for pluralization, singularization, and
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# uncountable words are kept in inflections.rb.
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#
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# The Rails core team has stated patches for the inflections library will not
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# be accepted in order to avoid breaking legacy applications which may be
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# relying on errant inflections. If you discover an incorrect inflection and
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# require it for your application or wish to define rules for languages other
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# than English, please correct or add them yourself (explained below).
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module Inflector
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extend self
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# Returns the plural form of the word in the string.
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#
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# If passed an optional +locale+ parameter, the word will be
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# pluralized using rules defined for that language. By default,
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# this parameter is set to <tt>:en</tt>.
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#
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# pluralize('post') # => "posts"
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# pluralize('octopus') # => "octopi"
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# pluralize('sheep') # => "sheep"
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# pluralize('words') # => "words"
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# pluralize('CamelOctopus') # => "CamelOctopi"
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# pluralize('ley', :es) # => "leyes"
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def pluralize(word, locale = :en)
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apply_inflections(word, inflections(locale).plurals)
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end
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# The reverse of #pluralize, returns the singular form of a word in a
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# string.
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#
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# If passed an optional +locale+ parameter, the word will be
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# singularized using rules defined for that language. By default,
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# this parameter is set to <tt>:en</tt>.
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#
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# singularize('posts') # => "post"
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# singularize('octopi') # => "octopus"
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# singularize('sheep') # => "sheep"
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# singularize('word') # => "word"
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# singularize('CamelOctopi') # => "CamelOctopus"
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# singularize('leyes', :es) # => "ley"
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def singularize(word, locale = :en)
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apply_inflections(word, inflections(locale).singulars)
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end
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# Converts strings to UpperCamelCase.
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# If the +uppercase_first_letter+ parameter is set to false, then produces
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# lowerCamelCase.
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#
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# Also converts '/' to '::' which is useful for converting
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# paths to namespaces.
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#
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# camelize('active_model') # => "ActiveModel"
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# camelize('active_model', false) # => "activeModel"
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# camelize('active_model/errors') # => "ActiveModel::Errors"
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# camelize('active_model/errors', false) # => "activeModel::Errors"
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#
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# As a rule of thumb you can think of +camelize+ as the inverse of
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# #underscore, though there are cases where that does not hold:
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#
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# camelize(underscore('SSLError')) # => "SslError"
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def camelize(term, uppercase_first_letter = true)
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string = term.to_s
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if uppercase_first_letter
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string = string.sub(/^[a-z\d]*/) { |match| inflections.acronyms[match] || match.capitalize }
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else
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string = string.sub(/^(?:#{inflections.acronym_regex}(?=\b|[A-Z_])|\w)/) { |match| match.downcase }
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end
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string.gsub!(/(?:_|(\/))([a-z\d]*)/i) { "#{$1}#{inflections.acronyms[$2] || $2.capitalize}" }
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string.gsub!('/'.freeze, '::'.freeze)
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string
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end
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# Makes an underscored, lowercase form from the expression in the string.
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#
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# Changes '::' to '/' to convert namespaces to paths.
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#
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# underscore('ActiveModel') # => "active_model"
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# underscore('ActiveModel::Errors') # => "active_model/errors"
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#
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# As a rule of thumb you can think of +underscore+ as the inverse of
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# #camelize, though there are cases where that does not hold:
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#
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# camelize(underscore('SSLError')) # => "SslError"
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def underscore(camel_cased_word)
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return camel_cased_word unless camel_cased_word =~ /[A-Z-]|::/
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word = camel_cased_word.to_s.gsub('::'.freeze, '/'.freeze)
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word.gsub!(/(?:(?<=([A-Za-z\d]))|\b)(#{inflections.acronym_regex})(?=\b|[^a-z])/) { "#{$1 && '_'.freeze }#{$2.downcase}" }
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word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2'.freeze)
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word.gsub!(/([a-z\d])([A-Z])/, '\1_\2'.freeze)
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word.tr!("-".freeze, "_".freeze)
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word.downcase!
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word
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end
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# Tweaks an attribute name for display to end users.
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#
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# Specifically, performs these transformations:
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#
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# * Applies human inflection rules to the argument.
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# * Deletes leading underscores, if any.
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# * Removes a "_id" suffix if present.
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# * Replaces underscores with spaces, if any.
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# * Downcases all words except acronyms.
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# * Capitalizes the first word.
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#
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# The capitalization of the first word can be turned off by setting the
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# +:capitalize+ option to false (default is true).
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#
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# humanize('employee_salary') # => "Employee salary"
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# humanize('author_id') # => "Author"
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# humanize('author_id', capitalize: false) # => "author"
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# humanize('_id') # => "Id"
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#
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# If "SSL" was defined to be an acronym:
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#
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# humanize('ssl_error') # => "SSL error"
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#
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def humanize(lower_case_and_underscored_word, options = {})
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result = lower_case_and_underscored_word.to_s.dup
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inflections.humans.each { |(rule, replacement)| break if result.sub!(rule, replacement) }
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result.sub!(/\A_+/, ''.freeze)
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result.sub!(/_id\z/, ''.freeze)
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result.tr!('_'.freeze, ' '.freeze)
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result.gsub!(/([a-z\d]*)/i) do |match|
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"#{inflections.acronyms[match] || match.downcase}"
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end
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if options.fetch(:capitalize, true)
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result.sub!(/\A\w/) { |match| match.upcase }
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end
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result
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end
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# Converts just the first character to uppercase.
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#
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# upcase_first('what a Lovely Day') # => "What a Lovely Day"
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# upcase_first('w') # => "W"
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# upcase_first('') # => ""
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def upcase_first(string)
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string.length > 0 ? string[0].upcase.concat(string[1..-1]) : ''
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end
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# Capitalizes all the words and replaces some characters in the string to
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# create a nicer looking title. +titleize+ is meant for creating pretty
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# output. It is not used in the Rails internals.
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#
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# +titleize+ is also aliased as +titlecase+.
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#
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# titleize('man from the boondocks') # => "Man From The Boondocks"
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# titleize('x-men: the last stand') # => "X Men: The Last Stand"
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# titleize('TheManWithoutAPast') # => "The Man Without A Past"
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# titleize('raiders_of_the_lost_ark') # => "Raiders Of The Lost Ark"
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def titleize(word)
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humanize(underscore(word)).gsub(/\b(?<!['’`])[a-z]/) { |match| match.capitalize }
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end
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# Creates the name of a table like Rails does for models to table names.
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# This method uses the #pluralize method on the last word in the string.
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#
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# tableize('RawScaledScorer') # => "raw_scaled_scorers"
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# tableize('ham_and_egg') # => "ham_and_eggs"
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# tableize('fancyCategory') # => "fancy_categories"
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def tableize(class_name)
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pluralize(underscore(class_name))
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end
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# Creates a class name from a plural table name like Rails does for table
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# names to models. Note that this returns a string and not a Class (To
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# convert to an actual class follow +classify+ with #constantize).
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#
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# classify('ham_and_eggs') # => "HamAndEgg"
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# classify('posts') # => "Post"
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#
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# Singular names are not handled correctly:
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#
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# classify('calculus') # => "Calculus"
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def classify(table_name)
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# strip out any leading schema name
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camelize(singularize(table_name.to_s.sub(/.*\./, ''.freeze)))
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end
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# Replaces underscores with dashes in the string.
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#
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# dasherize('puni_puni') # => "puni-puni"
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def dasherize(underscored_word)
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underscored_word.tr('_'.freeze, '-'.freeze)
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end
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# Removes the module part from the expression in the string.
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#
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# demodulize('ActiveRecord::CoreExtensions::String::Inflections') # => "Inflections"
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# demodulize('Inflections') # => "Inflections"
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# demodulize('::Inflections') # => "Inflections"
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# demodulize('') # => ""
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#
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# See also #deconstantize.
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def demodulize(path)
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path = path.to_s
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if i = path.rindex('::')
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path[(i+2)..-1]
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else
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path
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end
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end
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# Removes the rightmost segment from the constant expression in the string.
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#
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# deconstantize('Net::HTTP') # => "Net"
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# deconstantize('::Net::HTTP') # => "::Net"
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# deconstantize('String') # => ""
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# deconstantize('::String') # => ""
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# deconstantize('') # => ""
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#
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# See also #demodulize.
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def deconstantize(path)
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path.to_s[0, path.rindex('::') || 0] # implementation based on the one in facets' Module#spacename
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end
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# Creates a foreign key name from a class name.
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# +separate_class_name_and_id_with_underscore+ sets whether
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# the method should put '_' between the name and 'id'.
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#
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# foreign_key('Message') # => "message_id"
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# foreign_key('Message', false) # => "messageid"
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# foreign_key('Admin::Post') # => "post_id"
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def foreign_key(class_name, separate_class_name_and_id_with_underscore = true)
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underscore(demodulize(class_name)) + (separate_class_name_and_id_with_underscore ? "_id" : "id")
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end
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# Tries to find a constant with the name specified in the argument string.
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#
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# 'Module'.constantize # => Module
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# 'Foo::Bar'.constantize # => Foo::Bar
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#
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# The name is assumed to be the one of a top-level constant, no matter
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# whether it starts with "::" or not. No lexical context is taken into
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# account:
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#
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# C = 'outside'
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# module M
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# C = 'inside'
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# C # => 'inside'
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# 'C'.constantize # => 'outside', same as ::C
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# end
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#
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# NameError is raised when the name is not in CamelCase or the constant is
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# unknown.
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def constantize(camel_cased_word)
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names = camel_cased_word.split('::'.freeze)
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# Trigger a built-in NameError exception including the ill-formed constant in the message.
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Object.const_get(camel_cased_word) if names.empty?
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# Remove the first blank element in case of '::ClassName' notation.
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names.shift if names.size > 1 && names.first.empty?
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names.inject(Object) do |constant, name|
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if constant == Object
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constant.const_get(name)
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else
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candidate = constant.const_get(name)
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next candidate if constant.const_defined?(name, false)
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next candidate unless Object.const_defined?(name)
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# Go down the ancestors to check if it is owned directly. The check
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# stops when we reach Object or the end of ancestors tree.
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constant = constant.ancestors.inject do |const, ancestor|
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break const if ancestor == Object
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break ancestor if ancestor.const_defined?(name, false)
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const
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end
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# owner is in Object, so raise
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constant.const_get(name, false)
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end
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end
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end
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# Tries to find a constant with the name specified in the argument string.
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#
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# safe_constantize('Module') # => Module
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# safe_constantize('Foo::Bar') # => Foo::Bar
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#
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# The name is assumed to be the one of a top-level constant, no matter
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# whether it starts with "::" or not. No lexical context is taken into
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# account:
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#
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# C = 'outside'
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# module M
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# C = 'inside'
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# C # => 'inside'
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# safe_constantize('C') # => 'outside', same as ::C
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# end
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#
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# +nil+ is returned when the name is not in CamelCase or the constant (or
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# part of it) is unknown.
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#
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# safe_constantize('blargle') # => nil
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# safe_constantize('UnknownModule') # => nil
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# safe_constantize('UnknownModule::Foo::Bar') # => nil
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def safe_constantize(camel_cased_word)
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constantize(camel_cased_word)
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rescue NameError => e
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raise if e.name && !(camel_cased_word.to_s.split("::").include?(e.name.to_s) ||
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e.name.to_s == camel_cased_word.to_s)
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rescue ArgumentError => e
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raise unless e.message =~ /not missing constant #{const_regexp(camel_cased_word)}\!$/
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end
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# Returns the suffix that should be added to a number to denote the position
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# in an ordered sequence such as 1st, 2nd, 3rd, 4th.
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#
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# ordinal(1) # => "st"
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# ordinal(2) # => "nd"
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# ordinal(1002) # => "nd"
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# ordinal(1003) # => "rd"
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# ordinal(-11) # => "th"
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# ordinal(-1021) # => "st"
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def ordinal(number)
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abs_number = number.to_i.abs
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if (11..13).include?(abs_number % 100)
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"th"
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else
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case abs_number % 10
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when 1; "st"
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when 2; "nd"
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when 3; "rd"
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else "th"
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end
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end
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end
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# Turns a number into an ordinal string used to denote the position in an
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# ordered sequence such as 1st, 2nd, 3rd, 4th.
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#
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# ordinalize(1) # => "1st"
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# ordinalize(2) # => "2nd"
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# ordinalize(1002) # => "1002nd"
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# ordinalize(1003) # => "1003rd"
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# ordinalize(-11) # => "-11th"
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# ordinalize(-1021) # => "-1021st"
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def ordinalize(number)
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"#{number}#{ordinal(number)}"
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end
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private
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# Mounts a regular expression, returned as a string to ease interpolation,
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# that will match part by part the given constant.
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#
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# const_regexp("Foo::Bar::Baz") # => "Foo(::Bar(::Baz)?)?"
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# const_regexp("::") # => "::"
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def const_regexp(camel_cased_word) #:nodoc:
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parts = camel_cased_word.split("::".freeze)
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return Regexp.escape(camel_cased_word) if parts.blank?
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last = parts.pop
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parts.reverse.inject(last) do |acc, part|
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part.empty? ? acc : "#{part}(::#{acc})?"
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end
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end
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# Applies inflection rules for +singularize+ and +pluralize+.
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#
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# apply_inflections('post', inflections.plurals) # => "posts"
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# apply_inflections('posts', inflections.singulars) # => "post"
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def apply_inflections(word, rules)
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result = word.to_s.dup
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if word.empty? || inflections.uncountables.uncountable?(result)
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result
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else
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rules.each { |(rule, replacement)| break if result.sub!(rule, replacement) }
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result
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end
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end
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end
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end
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