validata

Validata is a Clojure library to validates maps. Its goals are:

• provide a simple, idiomatic Clojure API
• avoid using macros for the API
• validate data, not transform or coerce it
• make validation functions easy to compose
• make validation functions easy to extend
• use simple, easy-to-understand internals

There are many alternatives for validation in Clojure; I list some alternatives below. My goal is to make validata clean and simple relative to some of the other options.

Usage

Add this to your project.clj dependencies:

[validata "0.1.8"]

Here is an example:

(ns example.core
  (:require [validata.core :as v]))

(def validations
  {:uuid        [v/uuid-string v/required]
   :name        [v/string v/required]
   :notes       [v/string]
   :created-at  [v/timestamp-string]
   :updated-at  [v/timestamp-string]})

(v/errors {} validations)
; {:uuid ["key is required"], :name ["key is required"]}

(v/errors {:uuid "e0da523c-fdfc-46d5-bf6d-a895dd3235c1"} validations)
; {:name ["key is required"]}

(v/errors {:uuid "e0da523c-fdfc-46d5-bf6d-a895dd3235c1"
           :name "validata"
           :notes 2.7128} validations)
; {:notes ["value must be a string"]}

(v/errors {:uuid "e0da523c-fdfc-46d5-bf6d-a895dd3235c1"
           :name "validata"} validations)
; {}

(v/valid? {:uuid "e0da523c-fdfc-46d5-bf6d-a895dd3235c1"} validations)
; false

(v/valid? {:uuid "e0da523c-fdfc-46d5-bf6d-a895dd3235c1"
           :name "validata"} validations)
; true

To display errors for extra (unexpected keys), use this form of errors:

(v/errors {:uuid "ed2b4b7d-1111-47e1-aa79-5b204758cd01"
           :name "validata"
           :junk 42} validations false)
; {:junk [:error "key is unexpected"]}

Limitations

• only validates top-level keys and values
• strings are not internationalized

Other Validation Libraries

Clojure has many validation libraries; here are a few I've looked at:

• clj-decline
• clj-schema
• dvt
• valip
• validateur

The libraries have varying goals and approaches; take a look and give them a try. Please let me know if you see ideas that would benefit this project.

License

Copyright 2014 Bluemont Labs LLC

Distributed under the Eclipse Public License, the same as Clojure.