Initial commit adding document checkout support

apps/checkouts/models.py

@@ -0,0 +1,48 @@
+from __future__ import absolute_import
+
+import logging
+import datetime
+
+from django.db import models, IntegrityError
+from django.utils.translation import ugettext_lazy as _
+
+from documents.models import Document
+
+from .managers import DocumentCheckoutManager
+from .exceptions import DocumentAlreadyCheckedOut
+
+logger = logging.getLogger(__name__)
+
+
+class DocumentCheckout(models.Model):
+    """
+    Model to store the state and information of a document checkout
+    """
+    document = models.ForeignKey(Document, verbose_name=_(u'document'), unique=True, editable=False)
+    checkout_datetime = models.DateTimeField(verbose_name=_(u'checkout date and time'), editable=False)
+    expiration_datetime = models.DateTimeField(verbose_name=_(u'checkout expiration date and time'))
+    block_new_version = models.BooleanField(verbose_name=_(u'block new version upload'), help_text=_(u'Do not allow new version of this document to be uploaded.'))
+    #block_metadata
+    #block_editing
+    #block tag add/remove
+    
+    objects = DocumentCheckoutManager()
+    
+    def __unicode__(self):
+        return unicode(self.document)
+
+    def save(self, *args, **kwargs):
+        if not self.pk:
+            self.checkout_date = datetime.datetime.now()
+        try:
+            return super(DocumentCheckout, self).save(*args, **kwargs)
+        except IntegrityError:
+            raise DocumentAlreadyCheckedOut
+    
+    @models.permalink
+    def get_absolute_url(self):
+        return ('checkout_info', [self.document.pk])        
+        
+    class Meta:
+        verbose_name = _(u'document checkout')
+        verbose_name_plural = _(u'document checkouts')