From c39f1aa8a0eab5183a2e515f4271b18a2bd1ea0c Mon Sep 17 00:00:00 2001
From: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>
Date: Sat, 16 Jun 2012 02:03:14 -0400
Subject: [PATCH] Add form field clean method to detect if documents are
 already checked out

---
 apps/checkouts/forms.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/apps/checkouts/forms.py b/apps/checkouts/forms.py
index d2032ed124..cfdecee26e 100644
--- a/apps/checkouts/forms.py
+++ b/apps/checkouts/forms.py
@@ -7,6 +7,7 @@ from django.utils.translation import ugettext_lazy as _
 from django.core import validators
 
 from .models import DocumentCheckout
+from .exceptions import DocumentAlreadyCheckedOut
 
 
 class SplitDeltaWidget(forms.widgets.MultiWidget):
@@ -101,3 +102,9 @@ class DocumentCheckoutForm(forms.ModelForm):
         widgets = {
             'document': forms.widgets.HiddenInput(),
         }     
+
+    def clean_document(self):
+        document = self.cleaned_data['document']
+        if document.is_checked_out():
+            raise DocumentAlreadyCheckedOut
+        return document