From 776f0548ceae3f56135ee8ab99fdc01bb24abb01 Mon Sep 17 00:00:00 2001
From: Dustin Ingram <di@users.noreply.github.com>
Date: Fri, 20 Nov 2015 12:35:00 -0500
Subject: [PATCH] Fixes #12

---
 vladiate/test/test_validators.py | 4 ++++
 vladiate/validators.py           | 5 +++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/vladiate/test/test_validators.py b/vladiate/test/test_validators.py
index 3af8401..2ab1d2c 100644
--- a/vladiate/test/test_validators.py
+++ b/vladiate/test/test_validators.py
@@ -101,6 +101,10 @@ def test_regex_validator_works(pattern, field):
     RegexValidator(pattern).validate(field)
 
 
+def test_regex_validator_allows_empty():
+    RegexValidator(r'foo.*', empty_ok=True).validate('')
+
+
 @pytest.mark.parametrize('pattern, field', [
     (r'foo.*', 'afoo'),
     (r'^$', 'foo'),
diff --git a/vladiate/validators.py b/vladiate/validators.py
index 46bb46e..ec29380 100644
--- a/vladiate/validators.py
+++ b/vladiate/validators.py
@@ -119,13 +119,14 @@ def bad(self):
 class RegexValidator(Validator):
     ''' Validates that a field matches a given regex '''
 
-    def __init__(self, pattern=r'di^'):
+    def __init__(self, pattern=r'di^', empty_ok=False):
         super(RegexValidator, self).__init__()
         self.regex = re.compile(pattern)
+        self.empty_ok = empty_ok
         self.failures = set([])
 
     def validate(self, field, row={}):
-        if not self.regex.match(field):
+        if not self.regex.match(field) and (field or not self.empty_ok):
             self.failures.add(field)
             raise ValidationException(
                 "'{}' does not match pattern /{}/".format(field, self.regex))