Valip is a validation library for Clojure(Script). It is primarily designed to validate keyword-string maps, such as one might get from a HTML form.

This is an experimental fork of Chas Emerick' valip library that, in turn, was a fork of James Reeves' valip library.

1. I tried to make this fork compliant with the new Reader Conditional extension that was not available a the time Chas Emerick wrote his fork;
2. Since I was breaking stuff anyway, I fixed a security issue and added the coverage of corner cases, hopefully all for the better.

Add the following dependency to your project.clj file or to your build.boot file:

[org.clojars.magomimmo/valip "0.4.0-SNAPSHOT"]

The main validation function is valip.core/validate. It uses the following syntax:

(validate map-of-values
  [key1 predicate1 error1]
  [key2 predicate2 error2]
  ...
  [keyn predicaten errorn])

For each vector, the key is used to look up a value in the map. The map value is then tested with the predicate function. If the predicate fails, the error message is included in the map of errors returned by the validate function. A key may be tested multiple times with different predicates and errors.

If no predicate fails, nil is returned. If at least one predicate fails, a map of keys to errors is returned:

{key1 [error1]
 key2 [error2]
 ...
 keyn [errorn]}

The errors are listed in a vector, because there may be multiple errors for the same key.

For example:

(use 'valip.core 'valip.predicates)

(def user
  {:name "Alice", :age 7})

(validate user
  [:name present? "must be present"]
  [:age present? "must be present"]
  [:age (over 18) "must be over 18"])

=> {:age ["must be over 18"])

You can see an example of usage of the valip library in the modern-cljs series of tutorial on Clojure(Script).

Valip has a number of useful predicates and functions that generate predicates. More of these useful predicates will be eventually added as the library matures.

You can find predicates in the valip.predicates namespace which includes platform-specific predicates using the #? reader macro.

Copyright © 2012-2015 James Reeves and Chas Emerick

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