Create history entries for fields that are changed on a patch

3 files changed, 47 insertions, 2 deletions

diff --git a/pgcommitfest/commitfest/models.py b/pgcommitfest/commitfest/models.py
index 2538e08..090804b 100644
--- a/pgcommitfest/commitfest/models.py
+++ b/pgcommitfest/commitfest/models.py
@@ -3,6 +3,8 @@ from django.contrib.admin.models import User
 
 from datetime import datetime
 
+from util import DiffableModel
+
 # We have few enough of these, and it's really the only thing we
 # need to extend from the user model, so just create a separate
 # class.
@@ -52,7 +54,7 @@ class Topic(models.Model):
 		return self.topic
 
 
-class Patch(models.Model):
+class Patch(models.Model, DiffableModel):
 	name = models.CharField(max_length=500, blank=False, null=False, verbose_name='Description')
 	topic = models.ForeignKey(Topic, blank=False, null=False)
 
@@ -81,6 +83,10 @@ class Patch(models.Model):
 	# that's attached to this message.
 	lastmail = models.DateTimeField(blank=True, null=True)
 
+	map_manytomany_for_diff = {
+		'authors': 'authors_string',
+		'reviewers': 'reviewers_string',
+		}
 	# Some accessors
 	@property
 	def authors_string(self):
diff --git a/pgcommitfest/commitfest/util.py b/pgcommitfest/commitfest/util.py
new file mode 100644
index 0000000..862ee3d
--- /dev/null
+++ b/pgcommitfest/commitfest/util.py
@@ -0,0 +1,35 @@
+from django.forms.models import model_to_dict
+
+
+class DiffableModel(object):
+	"""
+	Make it possible to diff a model.
+    """
+
+	def __init__(self, *args, **kwargs):
+		super(DiffableModel, self).__init__(*args, **kwargs)
+		self.__initial = self._dict
+
+	@property
+	def diff(self):
+		manytomanyfieldnames = [f.name for f in self._meta.many_to_many]
+		d1 = self.__initial
+		d2 = self._dict
+		diffs = dict([(k, (v, d2[k])) for k, v in d1.items() if v != d2[k]])
+		if hasattr(self, 'map_manytomany_for_diff'):
+			for k,v in diffs.items():
+				if k in manytomanyfieldnames and self.map_manytomany_for_diff.has_key(k):
+					# Try to show the display name instead here
+					newvalue = getattr(self, self.map_manytomany_for_diff[k])
+					diffs[k] = (v[0], newvalue)
+		return diffs
+
+	def save(self, *args, **kwargs):
+		super(DiffableModel, self).save(*args, **kwargs)
+		self.__initial = self._dict
+
+	@property
+	def _dict(self):
+		fields = [field.name for field in self._meta.fields]
+		fields.extend([field.name for field in self._meta.many_to_many])
+		return model_to_dict(self, fields=fields)
diff --git a/pgcommitfest/commitfest/views.py b/pgcommitfest/commitfest/views.py
index 6fc23a1..1a8ed82 100644
--- a/pgcommitfest/commitfest/views.py
+++ b/pgcommitfest/commitfest/views.py
@@ -113,9 +113,13 @@ def patchform(request, cfid, patchid):
 			r = form.save(commit=False)
 			# Fill out any locked fields here
 
+			form.save_m2m()
+
+			# Track all changes
+			for field, values in r.diff.items():
+				PatchHistory(patch=patch, by=request.user, what='Changed %s to %s' % (field, values[1])).save()
 			r.set_modified()
 			r.save()
-			form.save_m2m()
 			return HttpResponseRedirect('../../%s/' % r.pk)
 		# Else fall through and render the page again
 	else: