From fa9676779bcc467e29fda0b81a06dac871f104f4 Mon Sep 17 00:00:00 2001
From: Julien Guimont <julien.guimont@gmail.com>
Date: Wed, 16 Nov 2011 22:37:43 -0500
Subject: [PATCH] Add the ability to create custom validation on fields

---
 lib/validatable.js           | 13 ++++++++++++-
 test/validations_test.coffee | 13 +++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/lib/validatable.js b/lib/validatable.js
index f8d55405..bde3b4fb 100644
--- a/lib/validatable.js
+++ b/lib/validatable.js
@@ -10,6 +10,16 @@ Validatable.validatesNumericalityOf = getConfigurator('numericality');
 Validatable.validatesInclusionOf = getConfigurator('inclusion');
 Validatable.validatesExclusionOf = getConfigurator('exclusion');
 Validatable.validatesFormatOf = getConfigurator('format');
+Validatable.validate = function(){
+    args = [].slice.call(arguments);
+    var valFn = function(){}; //noop
+    if (typeof args[args.length - 1] === 'function'){
+        valFn = args.pop();
+    }
+    wrapperFn = function(attr, conf, err){ return valFn.call( this, err) };
+    configure(this, wrapperFn, args)
+
+}
 
 // implementation of validators
 var validators = {
@@ -118,7 +128,8 @@ function validationFailed(inst, v) {
     if (skipValidation(inst, conf, 'unless')) return false;
 
     var fail = false;
-    validators[conf.validation].call(inst, attr, conf, function onerror(kind) {
+    var validator = typeof conf.validation === "function" ? conf.validation : validators[conf.validation];
+    validator.call(inst, attr, conf, function onerror(kind) {
         var message;
         if (conf.message) {
             message = conf.message;
diff --git a/test/validations_test.coffee b/test/validations_test.coffee
index d3e2c3cf..14bd4ec0 100644
--- a/test/validations_test.coffee
+++ b/test/validations_test.coffee
@@ -215,3 +215,16 @@ it 'should validate format', (test) ->
 
     test.done()
 
+it 'should validate a field using a custom validator', (test)->
+    
+    User.validate 'email', (err)-> err("crash") if @email.length is 0
+
+    user = new User validAttributes
+    test.ok user.isValid()
+
+    user = new User validAttributes
+    user.email = ""
+    test.ok not user.isValid()
+
+    test.done()
+