module ActiveSupport::Inflector
def apply_inflections(word, rules)
apply_inflections('post', inflections.plurals) # => "posts"
Applies inflection rules for +singularize+ and +pluralize+.
def apply_inflections(word, rules) result = word.to_s.dup if word.empty? || inflections.uncountables.include?(result.downcase[/\b\w+\Z/]) result else rules.each { |(rule, replacement)| break if result.sub!(rule, replacement) } result end end
def camelize(term, uppercase_first_letter = true)
+underscore+, though there are cases where that does not hold:
As a rule of thumb you can think of +camelize+ as the inverse of
'active_model/errors'.camelize(:lower) # => "activeModel::Errors"
'active_model/errors'.camelize # => "ActiveModel::Errors"
'active_model'.camelize(:lower) # => "activeModel"
'active_model'.camelize # => "ActiveModel"
paths to namespaces.
+camelize+ will also convert '/' to '::' which is useful for converting
lowerCamelCase.
to +camelize+ is set to :lower then +camelize+ produces
By default, +camelize+ converts strings to UpperCamelCase. If the argument
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 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
def classify(table_name)
Singular names are not handled correctly:
'posts'.classify # => "Post"
'egg_and_hams'.classify # => "EggAndHam"
convert to an actual class follow +classify+ with +constantize+).
names to models. Note that this returns a string and not a Class (To
Create a class name from a plural table name like Rails does for table
def classify(table_name) # strip out any leading schema name camelize(singularize(table_name.to_s.sub(/.*\./, ''))) end
def const_regexp(camel_cased_word) #:nodoc:
For instance, Foo::Bar::Baz will generate Foo(::Bar(::Baz)?)?
Mount a regular expression that will match part by part of the constant.
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
def constantize(camel_cased_word)
NameError is raised when the name is not in CamelCase or the constant is
end
'C'.constantize # => 'outside', same as ::C
C # => 'inside'
C = 'inside'
module M
C = 'outside'
account:
whether it starts with "::" or not. No lexical context is taken into
The name is assumed to be the one of a top-level constant, no matter
'Test::Unit'.constantize # => Test::Unit
'Module'.constantize # => Module
Tries to find a constant with the name specified in the argument string.
def constantize(camel_cased_word) names = camel_cased_word.split('::') names.shift if names.empty? || names.first.empty? names.inject(Object) do |constant, name| if constant == Object constant.const_get(name) else candidate = constant.const_get(name) next candidate if constant.const_defined?(name, false) next candidate unless Object.const_defined?(name) # Go down the ancestors to check it it's owned # directly before we reach Object or the end of ancestors. constant = constant.ancestors.inject do |const, ancestor| break const if ancestor == Object break ancestor if ancestor.const_defined?(name, false) const end # owner is in Object, so raise constant.const_get(name, false) end end end
def dasherize(underscored_word)
Replaces underscores with dashes in the string.
def dasherize(underscored_word) underscored_word.tr('_', '-') end
def deconstantize(path)
''.deconstantize # => ""
'::String'.deconstantize # => ""
'String'.deconstantize # => ""
'::Net::HTTP'.deconstantize # => "::Net"
'Net::HTTP'.deconstantize # => "Net"
Removes the rightmost segment from the constant expression in the string.
def deconstantize(path) path.to_s[0...(path.rindex('::') || 0)] # implementation based on the one in facets' Module#spacename end
def demodulize(path)
'Inflections'.demodulize # => "Inflections"
'ActiveRecord::CoreExtensions::String::Inflections'.demodulize # => "Inflections"
Removes the module part from the expression in the string.
def demodulize(path) path = path.to_s if i = path.rindex('::') path[(i+2)..-1] else path end end
def foreign_key(class_name, separate_class_name_and_id_with_underscore = true)
'Message'.foreign_key(false) # => "messageid"
'Message'.foreign_key # => "message_id"
the method should put '_' between the name and 'id'.
+separate_class_name_and_id_with_underscore+ sets whether
Creates a foreign key name from a class name.
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
def humanize(lower_case_and_underscored_word)
'employee_salary'.humanize # => "Employee salary"
output.
trailing "_id", if any. Like +titleize+, this is meant for creating pretty
Capitalizes the first word and turns underscores into spaces and strips a
def humanize(lower_case_and_underscored_word) result = lower_case_and_underscored_word.to_s.dup inflections.humans.each { |(rule, replacement)| break if result.sub!(rule, replacement) } result.gsub!(/_id$/, "") result.tr!('_', ' ') result.gsub(/([a-z\d]*)/i) { |match| "#{inflections.acronyms[match] || match.downcase}" }.gsub(/^\w/) { $&.upcase } end
def inflections(locale = :en)
inflect.uncountable 'rails'
ActiveSupport::Inflector.inflections(:en) do |inflect|
Only rules for English are provided.
languages can be specified. If not specified, defaults to :en.
additional inflector rules. If passed an optional locale, rules for other
Yields a singleton instance of Inflector::Inflections so you can specify
def inflections(locale = :en) if block_given? yield Inflections.instance(locale) else Inflections.instance(locale) end end
def ordinal(number)
ordinal(-11) # => "th"
ordinal(1003) # => "rd"
ordinal(1002) # => "nd"
ordinal(2) # => "nd"
ordinal(1) # => "st"
in an ordered sequence such as 1st, 2nd, 3rd, 4th.
Returns the suffix that should be added to a number to denote the position
def ordinal(number) abs_number = number.to_i.abs if (11..13).include?(abs_number % 100) "th" else case abs_number % 10 when 1; "st" when 2; "nd" when 3; "rd" else "th" end end end
def ordinalize(number)
ordinalize(-11) # => "-11th"
ordinalize(1003) # => "1003rd"
ordinalize(1002) # => "1002nd"
ordinalize(2) # => "2nd"
ordinalize(1) # => "1st"
ordered sequence such as 1st, 2nd, 3rd, 4th.
Turns a number into an ordinal string used to denote the position in an
def ordinalize(number) "#{number}#{ordinal(number)}" end
def parameterize(string, sep = '-')
<%= link_to(@person.name, person_path(@person)) %>
# => #
@person = Person.find(1)
end
end
"#{id}-#{name.parameterize}"
def to_param
class Person
a 'pretty' URL.
Replaces special characters in a string so that it may be used as part of
def parameterize(string, sep = '-') # replace accented chars with their ascii equivalents parameterized_string = transliterate(string) # Turn unwanted chars into the separator parameterized_string.gsub!(/[^a-z0-9\-_]+/i, sep) unless sep.nil? || sep.empty? re_sep = Regexp.escape(sep) # No more than one of the separator in a row. parameterized_string.gsub!(/#{re_sep}{2,}/, sep) # Remove leading/trailing separator. parameterized_string.gsub!(/^#{re_sep}|#{re_sep}$/i, '') end parameterized_string.downcase end
def pluralize(word, locale = :en)
'CamelOctopus'.pluralize # => "CamelOctopi"
'words'.pluralize # => "words"
'sheep'.pluralize # => "sheep"
'octopus'.pluralize # => "octopi"
'post'.pluralize # => "posts"
this parameter is set to :en.
pluralized using rules defined for that language. By default,
If passed an optional +locale+ parameter, the word will be
Returns the plural form of the word in the string.
def pluralize(word, locale = :en) apply_inflections(word, inflections(locale).plurals) end
def safe_constantize(camel_cased_word)
'UnknownModule'.safe_constantize # => nil
'blargle'.safe_constantize # => nil
part of it) is unknown.
+nil+ is returned when the name is not in CamelCase or the constant (or
end
'C'.safe_constantize # => 'outside', same as ::C
C # => 'inside'
C = 'inside'
module M
C = 'outside'
account:
whether it starts with "::" or not. No lexical context is taken into
The name is assumed to be the one of a top-level constant, no matter
'Test::Unit'.safe_constantize # => Test::Unit
'Module'.safe_constantize # => Module
Tries to find a constant with the name specified in the argument string.
def safe_constantize(camel_cased_word) constantize(camel_cased_word) rescue NameError => e raise unless e.message =~ /(uninitialized constant|wrong constant name) #{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
def singularize(word, locale = :en)
'CamelOctopi'.singularize # => "CamelOctopus"
'word'.singularize # => "word"
'sheep'.singularize # => "sheep"
'octopi'.singularize # => "octopus"
'posts'.singularize # => "post"
this parameter is set to :en.
pluralized using rules defined for that language. By default,
If passed an optional +locale+ parameter, the word will be
string.
The reverse of +pluralize+, returns the singular form of a word in a
def singularize(word, locale = :en) apply_inflections(word, inflections(locale).singulars) end
def tableize(class_name)
'egg_and_ham'.tableize # => "egg_and_hams"
'RawScaledScorer'.tableize # => "raw_scaled_scorers"
method uses the +pluralize+ method on the last word in the string.
Create the name of a table like Rails does for models to table names. This
def tableize(class_name) pluralize(underscore(class_name)) end
def titleize(word)
'TheManWithoutAPast'.titleize # => "The Man Without A Past"
'x-men: the last stand'.titleize # => "X Men: The Last Stand"
'man from the boondocks'.titleize # => "Man From The Boondocks"
+titleize+ is also aliased as +titlecase+.
output. It is not used in the Rails internals.
create a nicer looking title. +titleize+ is meant for creating pretty
Capitalizes all the words and replaces some characters in the string to
def titleize(word) humanize(underscore(word)).gsub(/\b(?<!['’`])[a-z]/) { $&.capitalize } end
def transliterate(string, replacement = "?")
transliterate('Jürgen')
I18n.locale = :de
# => "Jurgen"
transliterate('Jürgen')
I18n.locale = :en
Now you can have different transliterations for each locale:
})
}
rule: ->(string) { MyTransliterator.transliterate(string) }
transliterate: {
I18n.backend.store_translations(:de, i18n: {
complex requirements, a Proc:
maps characters to ASCII approximations as shown above, or, for more
The value for i18n.transliterate.rule can be a simple Hash that
})
}
}
'ö' => 'oe'
'ü' => 'ue',
rule: {
transliterate: {
I18n.backend.store_translations(:de, i18n: {
# Or set them using Ruby
ö: "oe"
ü: "ue"
rule:
transliterate:
i18n:
# Store the transliterations in locales/de.yml
them as the i18n.transliterate.rule i18n key:
In order to make your custom transliterations available, you must set
to ASCII.
and "ö" to "ue" and "oe", or to add support for transliterating Russian
locale. This can be useful, for example, to transliterate German's "ü"
This method is I18n aware, so you can set up custom approximations for a
e.g, "ø", "ñ", "é", "ß", etc.
Default approximations are provided for Western/Latin characters,
# => "AEroskobing"
transliterate('Ærøskøbing')
exists, a replacement character which defaults to "?".
Replaces non-ASCII characters with an ASCII approximation, or if none
def transliterate(string, replacement = "?") I18n.transliterate(ActiveSupport::Multibyte::Unicode.normalize( ActiveSupport::Multibyte::Unicode.tidy_bytes(string), :c), :replacement => replacement) end
def underscore(camel_cased_word)
+camelize+, though there are cases where that does not hold:
As a rule of thumb you can think of +underscore+ as the inverse of
'ActiveModel::Errors'.underscore # => "active_model/errors"
'ActiveModel'.underscore # => "active_model"
Changes '::' to '/' to convert namespaces to paths.
Makes an underscored, lowercase form from the expression in the string.
def underscore(camel_cased_word) word = camel_cased_word.to_s.dup word.gsub!('::', '/') 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