underscore.inflection

underscore.inflection

Another javascript inflector?!

I'll be the first to say it; this isn't the first port of ActiveSupport::Inflector to js. Not by a long shot. But I'll definitely take underscore mixins over extending String.prototype or other clunky implementations any day.

Also, this one has tests!

Inflections

The methods listed below are the ones you'll be using 99% of the time.

pluralize

Signature: _.pluralize(word)

pluralize pluralizes the string passed to it.

// functional style
_.pluralize('word'); // => 'words'

// object-oriented style
_('word').pluralize(); // => 'words'

It also can accept a number as the second parameter. If a number is provided, it will pluralize the word to match the number.

_('word').pluralize(0); // => 'words'
_('word').pluralize(1); // => 'word'
_('word').pluralize(1.5); // => 'words'

Optionally, you can pass true as a third parameter. If found, this will include the count with the output.

_('word').pluralize(0, true); // => '0 words'
_('word').pluralize(1, true); // => '1 word'

singularize

Signature: _.singularize(word)

singularize returns the singular version of the plural passed to it.

// functional style
_.singularize('words'); // => 'word'

// object-oriented style
_('words').singularize(); // => 'word'

gsub

Signature: _.gsub(word, rule, replacement)

gsub is a method that is just slightly different than our standard String#replace. The main differences are that it matches globally every time, and if no substitution is made it returns null. It accepts a string for word and replacement, and rule can be either a string or a regex.

// functional style
_.gsub('word', /wo/, 'ne'); // => 'nerd'

// object-oriented style
_('word').gsub(/wo/, 'ne'); // => 'nerd'

ordinalize

Signature: _.uncountable(number)

ordinalize adds an ordinal suffix to number.

_.ordinalize(1);    // => '1st'
_.ordinalize("5");  // => '5th'
_.ordinalize(11);   // => '11th'
_.ordinalize(1033); // => '1033rd'
_.ordinalize(-15);  // => '-15th'

titleize

Signature: _.titleize( words )

titleize capitalizes the first letter of each word in the string words. It preserves the existing whitespace.

_.titleize('banana');               // => 'Banana'
_.titleize('banana potato fork');   // => 'Banana Potato Fork'
_.titleize('banana  potato\tfork'); // => 'Banana  Potato\tFork'

Configuring the Inflector

Should you ever need to configure the Inflector beyond the defaults, use these methods to do so:

plural

Signature: _.plural(rule, replacement)

plural creates a new pluralization rule for the inflector. rule can be either a string or a regex.

// functional style with explicit string
_.plural('axis', 'axes');

// object-oriented style with explicit string
_('axis').plural('axes');

// functional style with regex
_.plural(/(ax)is$/i, '$1es');

// object-oriented style with regex
_(/(ax)is$/i).plural('$1es');

singular

Signature: _.singular(rule, replacement)

singular creates a new singularization rule for the inflector. rule can be either a string or a regex.

// functional style with explicit string
_.singular('data', 'datum');

// object-oriented style with explicit string
_('data').singular('datum');

// functional style with regex
_.singular(/(t)a$/i, '$1um');

// object-oriented style with regex
_(/(t)a$/i).singular('$1um');

irregular

Signature: _.irregular(singular, plural)

irregular is a shortcut method to create both a pluralization and singularization rule for the word at the same time. You must supply both the singular form and the plural form as explicit strings.

// functional style
_.irregular('haxor', 'hax0rs!');

// object-oriented style
_('haxor').irregular('hax0rs!');

uncountable

Signature: _.uncountable(word)

uncountable creates a new uncountable rule for word. Uncountable words do not get pluralized or singularized.

// functional style
_.uncountable('equipment');

// object-oriented style
_('equipment').uncountable();

resetInflections

Signature: _.resetInflections()

resetInflections resets the inflector's rules to their initial state, clearing out any custom rules that have been added.

Thanks to...

The Rails team for ActiveSupport

The DocumentCloud team for underscore.js

These other Inflector implementations:

• active-support-for-javascript
• inflection-js
• Javascript Rails-like inflector

Though no code was taken directly from them, they deserve plenty of props for doing it before me. If underscore isn't your thing, check them out!