node-units

Node.JS unit conversion library with customizable units

npm install node-units
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Node Units

A unit conversion library for Node.JS that comes with a default unit conversion database and the ability to extend the database with custom metrics.

Installing

npm install node-units

Usage

Functions

  • importDB(file_name, cb) - imports a custom unit database, cb takes a single argument err
  • importDBSync(file_name) - the sync version of importDB
  • getDB() - returns he currently used database of units as an object
  • getUnitType(unit) - given a single unit it will return back {'type': <unit_group>, 'unit': <base_unit>, 'modifier': <unit_modifier>}
  • convert(conversion_string) - where conversion_string is of the form <value> <from_unit> to <to_unit>

Properties

  • types - types is an object containing constants for each unit group.

types with the default unit database looks like:

{'TIME': 'time',
 'VOLUME': 'volume'};

Simple Usage

var units = require('node-units');

var result = units.convert('5 gills to mL');
// result == 591.4705

units.convert('five days to seconds');

Custom Units

With node-units you can import custom unit definitions from files defined like the following:

group:
  longname,longname,ln    1ln
  anotherunit,au          5ln
  onemore,om              2au
var units = require('node-units');

units.importDBSync('my_custom.units');

var result = units.convert('five au to onemores');
// result == 10

With custom units you can also overwrite any previously defined units.

time:
  minute,m        50s
var units = require('node-units');

units.importDBSync('my_custom.units');

var result = units.convert('5 minutes to s');
// result == 250

Values

node-units uses numberizer which is used to convert string versions of numbers into digits, for example, forty two becomes 42 and one fifth becomes 0.2.

What is currently not supported is mathematical symbols like 1/5 days.

Prefixes

node-units comes with a plethora of built in long and shortname unit prefixes like:

  • nano-, n-
  • micro-, mu-
  • mega-
  • giga-
  • milli-, m-
  • centi-, c-
  • and others

Variations

node-units also understands that it makes more sense to say things like five days rather than five day so when a unit is not know it will automatically look if the unit ends with either s, es or ies.

License

The MIT License (MIT) Copyright (c) 2013 Brett Langdon

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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