Class | String |
In: |
lib/sequel/extensions/core_extensions.rb
lib/sequel/extensions/string_date_time.rb lib/sequel/extensions/blank.rb lib/sequel/extensions/inflector.rb |
Parent: | Object |
The inflector extension adds inflection instance methods to String, which allows the easy transformation of words from singular to plural, class names to table names, modularized class names to ones without, and class names to foreign keys. It exists for backwards compatibility to legacy Sequel code.
To load the extension:
Sequel.extension :inflector
Yield the Inflections module if a block is given, and return the Inflections module.
# File lib/sequel/extensions/inflector.rb, line 100 100: def self.inflections 101: yield Inflections if block_given? 102: Inflections 103: end
Strings are blank if they are empty or include only whitespace
# File lib/sequel/extensions/blank.rb, line 37 37: def blank? 38: strip.empty? 39: end
By default, camelize converts the string 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 lib/sequel/extensions/inflector.rb, line 115 115: def camelize(first_letter_in_uppercase = :upper) 116: s = gsub(/\/(.?)/){|x| "::#{x[-1..-1].upcase unless x == '/'}"}.gsub(/(^|_)(.)/){|x| x[-1..-1].upcase} 117: s[0...1] = s[0...1].downcase unless first_letter_in_uppercase == :upper 118: s 119: end
Singularizes and camelizes the string. Also strips out all characters preceding and including a period (".").
Examples
"egg_and_hams".classify #=> "EggAndHam" "post".classify #=> "Post" "schema.post".classify #=> "Post"
# File lib/sequel/extensions/inflector.rb, line 129 129: def classify 130: sub(/.*\./, '').singularize.camelize 131: end
Constantize tries to find a declared constant with the name specified in the string. It raises a NameError when the name is not in CamelCase or is not initialized.
Examples
"Module".constantize #=> Module "Class".constantize #=> Class
# File lib/sequel/extensions/inflector.rb, line 140 140: def constantize 141: raise(NameError, "#{inspect} is not a valid constant name!") unless m = /\A(?:::)?([A-Z]\w*(?:::[A-Z]\w*)*)\z/.match(self) 142: Object.module_eval("::#{m[1]}", __FILE__, __LINE__) 143: end
Replaces underscores with dashes in the string.
Example
"puni_puni".dasherize #=> "puni-puni"
# File lib/sequel/extensions/inflector.rb, line 149 149: def dasherize 150: gsub(/_/, '-') 151: end
Removes the module part from the expression in the string
Examples
"ActiveRecord::CoreExtensions::String::Inflections".demodulize #=> "Inflections" "Inflections".demodulize #=> "Inflections"
# File lib/sequel/extensions/inflector.rb, line 158 158: def demodulize 159: gsub(/^.*::/, '') 160: end
Creates a foreign key name from a class name. use_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/sequel/extensions/inflector.rb, line 169 169: def foreign_key(use_underscore = true) 170: "#{demodulize.underscore}#{'_' if use_underscore}id" 171: end
Capitalizes the first word and turns underscores into spaces and strips _id. Like titleize, this is meant for creating pretty output.
Examples
"employee_salary" #=> "Employee salary" "author_id" #=> "Author"
# File lib/sequel/extensions/inflector.rb, line 179 179: def humanize 180: gsub(/_id$/, "").gsub(/_/, " ").capitalize 181: end
Converts a string into a Sequel::LiteralString, in order to override string literalization, e.g.:
DB[:items].filter(:abc => 'def').sql #=> "SELECT * FROM items WHERE (abc = 'def')" DB[:items].filter(:abc => 'def'.lit).sql #=> "SELECT * FROM items WHERE (abc = def)"
You can also provide arguments, to create a Sequel::SQL::PlaceholderLiteralString:
DB[:items].select{|o| o.count('DISTINCT ?'.lit(:a))}.sql #=> "SELECT count(DISTINCT a) FROM items"
# File lib/sequel/extensions/core_extensions.rb, line 189 189: def lit(*args) 190: args.empty? ? Sequel::LiteralString.new(self) : Sequel::SQL::PlaceholderLiteralString.new(self, args) 191: end
Returns the plural form of the word in the string.
Examples
"post".pluralize #=> "posts" "octopus".pluralize #=> "octopi" "sheep".pluralize #=> "sheep" "words".pluralize #=> "words" "the blue mailman".pluralize #=> "the blue mailmen" "CamelOctopus".pluralize #=> "CamelOctopi"
# File lib/sequel/extensions/inflector.rb, line 192 192: def pluralize 193: result = dup 194: Inflections.plurals.each{|(rule, replacement)| break if result.gsub!(rule, replacement)} unless Inflections.uncountables.include?(downcase) 195: result 196: 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".singluarize #=> "word" "the blue mailmen".singularize #=> "the blue mailman" "CamelOctopi".singularize #=> "CamelOctopus"
# File lib/sequel/extensions/inflector.rb, line 207 207: def singularize 208: result = dup 209: Inflections.singulars.each{|(rule, replacement)| break if result.gsub!(rule, replacement)} unless Inflections.uncountables.include?(downcase) 210: result 211: end
Underscores and pluralizes the string.
Examples
"RawScaledScorer".tableize #=> "raw_scaled_scorers" "egg_and_ham".tableize #=> "egg_and_hams" "fancyCategory".tableize #=> "fancy_categories"
# File lib/sequel/extensions/inflector.rb, line 219 219: def tableize 220: underscore.pluralize 221: 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.
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/sequel/extensions/inflector.rb, line 231 231: def titleize 232: underscore.humanize.gsub(/\b([a-z])/){|x| x[-1..-1].upcase} 233: end
Converts a string into a Date object.
# File lib/sequel/extensions/string_date_time.rb, line 11 11: def to_date 12: begin 13: Date.parse(self, Sequel.convert_two_digit_years) 14: rescue => e 15: raise Sequel.convert_exception_class(e, Sequel::InvalidValue) 16: end 17: end
Converts a string into a DateTime object.
# File lib/sequel/extensions/string_date_time.rb, line 20 20: def to_datetime 21: begin 22: DateTime.parse(self, Sequel.convert_two_digit_years) 23: rescue => e 24: raise Sequel.convert_exception_class(e, Sequel::InvalidValue) 25: end 26: end
Returns a Sequel::SQL::Blob that holds the same data as this string. Blobs provide proper escaping of binary data.
# File lib/sequel/extensions/core_extensions.rb, line 195 195: def to_sequel_blob 196: ::Sequel::SQL::Blob.new(self) 197: end
Converts a string into a Time or DateTime object, depending on the value of Sequel.datetime_class
# File lib/sequel/extensions/string_date_time.rb, line 30 30: def to_sequel_time 31: begin 32: if Sequel.datetime_class == DateTime 33: DateTime.parse(self, Sequel.convert_two_digit_years) 34: else 35: Sequel.datetime_class.parse(self) 36: end 37: rescue => e 38: raise Sequel.convert_exception_class(e, Sequel::InvalidValue) 39: end 40: end
Converts a string into a Time object.
# File lib/sequel/extensions/string_date_time.rb, line 43 43: def to_time 44: begin 45: Time.parse(self) 46: rescue => e 47: raise Sequel.convert_exception_class(e, Sequel::InvalidValue) 48: end 49: end
The reverse of camelize. Makes an underscored form from the expression in the string. Also changes ’::’ to ’/’ to convert namespaces to paths.
Examples
"ActiveRecord".underscore #=> "active_record" "ActiveRecord::Errors".underscore #=> active_record/errors
# File lib/sequel/extensions/inflector.rb, line 242 242: def underscore 243: gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2'). 244: gsub(/([a-z\d])([A-Z])/,'\1_\2').tr("-", "_").downcase 245: end