String inflections define new methods on the String class to transform names for different purposes. For instance, you can figure out the name of a database from the name of a class.
"ScaleScore".tableize => "scale_scores"
- camelcase
- camelize
- classify
- constantize
- dasherize
- demodulize
- foreign_key
- humanize
- pluralize
- singularize
- tableize
- titlecase
- titleize
- underscore
Alias for camelize
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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 46 46: def camelize(first_letter = :upper) 47: case first_letter 48: when :upper then Inflector.camelize(self, true) 49: when :lower then Inflector.camelize(self, false) 50: end 51: end
Create a class name from a 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" "post".classify #=> "Post"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 114 114: def classify 115: Inflector.classify(self) 116: 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
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 147 147: def constantize 148: Inflector.constantize(self) 149: end
Replaces underscores with dashes in the string.
Example
"puni_puni" #=> "puni-puni"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 83 83: def dasherize 84: Inflector.dasherize(self) 85: end
Removes the module part from the expression in the string
Examples
"ActiveRecord::CoreExtensions::String::Inflections".demodulize #=> "Inflections" "Inflections".demodulize #=> "Inflections"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 92 92: def demodulize 93: Inflector.demodulize(self) 94: 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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 136 136: def foreign_key(separate_class_name_and_id_with_underscore = true) 137: Inflector.foreign_key(self, separate_class_name_and_id_with_underscore) 138: 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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 124 124: def humanize 125: Inflector.humanize(self) 126: 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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 19 19: def pluralize 20: Inflector.pluralize(self) 21: 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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 32 32: def singularize 33: Inflector.singularize(self) 34: 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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 103 103: def tableize 104: Inflector.tableize(self) 105: end
Alias for titleize
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"
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 63 63: def titleize 64: Inflector.titleize(self) 65: end
The reverse of camelize. Makes an underscored 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
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# File vendor/rails/activesupport/lib/active_support/core_ext/string/inflections.rb, line 75 75: def underscore 76: Inflector.underscore(self) 77: end