First version

jsignature/mixins.py

@@ -0,0 +1,36 @@
+"""
+    A django mixin providing fields to store a signature captured
+    with jSignature jQuery plugin
+"""
+from datetime import datetime
+from django.db import models
+from django.utils.translation import ugettext_lazy as _
+from .fields import JSignatureField
+
+class JSignatureFieldsMixin(models.Model):
+    """ Mixin class providing fields to store a signature with jSignature """
+    signature = JSignatureField(
+        _('Signature'),
+        blank=True,
+        null=True)
+    signature_date = models.DateTimeField(
+        _('Signature date'),
+        blank=True,
+        null=True)
+
+    class Meta:
+        abstract = True
+
+    def save(self, *args, **kwargs):
+
+        is_new = self.pk is None
+        original = not is_new and self.__class__.objects.get(pk=self.pk) or None
+
+        print self.signature
+        if self.signature:
+            if is_new or self.signature != original.signature:
+                self.signature_date = datetime.now()
+        else:
+            self.signature_date = None
+
+        super(JSignatureFieldsMixin, self).save()