Data.Validation
The Validation(a, b)
is a disjunction that's more appropriate for validating
inputs, or any use case where you want to aggregate failures. Not only the
Validation
provides a better terminology for working with such cases
(Failure
and Success
versus Left
and Right
), it also allows one to
easily aggregate failures and successes as an Applicative Functor.
Example
var Validation = var Success = ValidationSuccessvar Failure = ValidationFailure // Functions that need to do validation return one of two cases://// - A Success with the value they want to propagate.// - Some value representing one or more failures, using a semigroup.// Lists are the more straight-forward semigroup, so we just use them// here. { return alength > 6? : /* otherwise */ } { return /[\W]/? : /* otherwise */ } // To aggregate the failures, we start with a Success case containing// a curried function of arity N (where N is the number of validations),// and we just use an `.ap`-ply chain to get either the value our Success// function ultimately returns, or the aggregated failures. { return } // => Validation.Failure([// "Password must have more than 6 characters.",// "Password must contain special characters."// ]) // => Validation.Failure([// "Password must contain special characters."// ]) // => Validation.Success("rosesarered$andstuff")
Installing
The easiest way is to grab it from NPM. If you're running in a Browser environment, you can use Browserify
$ npm install data.validation
Using with CommonJS
If you're not using NPM, Download the latest release, and require
the data.validation.umd.js
file:
var Validation =
Using with AMD
Download the latest release, and require the data.validation.umd.js
file:
Using without modules
Download the latest release, and load the data.validation.umd.js
file. The properties are exposed in the global folktale.data.validation
object:
Compiling from source
If you want to compile this library from the source, you'll need Git, Make, Node.js, and run the following commands:
$ git clone git://github.com/folktale/data.validation.git
$ cd data.validation
$ npm install
$ make bundle
This will generate the dist/data.validation.umd.js
file, which you can load in
any JavaScript environment.
Documentation
You can read the documentation online or build it yourself:
$ git clone git://github.com/folktale/data.validation.git
$ cd data.validation
$ npm install
$ make documentation
Then open the file docs/index.html
in your browser.
Platform support
This library assumes an ES5 environment, but can be easily supported in ES3 platforms by the use of shims. Just include es5-shim :)
Licence
Copyright (c) 2013 Quildreen Motta.
Released under the MIT licence.