Order and Purchase now consistend (Fixes #14)

k4ever/api/views.py

@@ -42,19 +42,15 @@ def buyItem(request, itemid, buymode=""):
 			"with/deposit"  item and deposit
 			"only/deposit"  only deposit
 	"""
-	order = Order()
-	order.create(user)
+	order = Order(user=request.user)
 	order.save() # for the id!
 	if buymode == "" or buymode == "with/deposit":
-		p = Purchase.create(order, item, isDeposit=False)
-		p.order = order
-		p.save()
+		p = Purchase(order=order, buyable=item, isDeposit=False)
+		p.save(saveOrder=False)
 	# TANNEK! if buymode == "with/dopsit" or buymode == "only/deposit":
 	if buymode == "with/deposit" or buymode == "only/deposit":
-		p = Purchase.create(order, item, isDeposit=True)
-		p.order = order
-		p.save()
-	order.updatePrice(commit=True)
+		p = Purchase(order=order, buyable=item, isDeposit=True)
+		p.save(saveOrder=False)
 	order.save()
 	
 	#return json-container

k4ever/api2/handlers.py

@@ -92,18 +92,16 @@ class BuyableItemHandler(BaseHandler):
 		if (not item.hasDeposit() and deposit != self.BUY_ITEM) or \
 				deposit not in (self.BUY_ITEM, self.BUY_DEPOSIT, self.BUY_ITEM_AND_DEPOSIT):
 			return rc.BAD_REQUEST
-		order = Order()
-		order.create(request.user)
+		order = Order(user=request.user)
 		order.save()
 		
 		for i in range(amount):
 			if deposit == self.BUY_ITEM or deposit == self.BUY_ITEM_AND_DEPOSIT:
-				p = Purchase.create(order, item, isDeposit=False)
-				p.save()
+				p = Purchase(order=order, buyable=item, isDeposit=False)
+				p.save(saveOrder=False)
 			if deposit == self.BUY_DEPOSIT or deposit == self.BUY_ITEM_AND_DEPOSIT:
-				p = Purchase.create(order, item, isDeposit=True)
-				p.save()
-		order.updatePrice(commit=True)
+				p = Purchase(order=order, buyable=item, isDeposit=True)
+				p.save(saveOrder=False)
 		order.save()
 		
 		return rc.CREATED
@@ -159,20 +157,16 @@ class BuyableItemHandler(BaseHandler):
 				if item in request.data['deposits'] and not ids[item].hasDeposit():
 					return getError(rc.BAD_REQUEST, "Item '%s' cant be bought with deposit" % (item,))
 		
-		order = Order()
-		order.create(request.user)
-		order.save()
-		purchases = []
+		order = Order(user=request.user)
+		order.save() # one save, for the id
 		# buy items
 		for item in request.data['items']:
-			p = Purchase.create(order, ids[item], isDeposit=False)
-			p.save()
+			p = Purchase(order=order, buyable=ids[item], isDeposit=False)
+			p.save(saveOrder=False)
 		# buy deposits
 		for item in request.data['deposits']:
-			p = Purchase.create(order, ids[item], isDeposit=True)
-			p.save()
-		
-		order.updatePrice(commit=True)
+			p = Purchase(order=order, buyable=ids[item], isDeposit=True)
+			p.save(saveOrder=False)
 		order.save()
 		
 		return rc.CREATED

k4ever/buyable/models.py

@@ -3,6 +3,7 @@ from django.db import models
 from django.contrib.auth.models import User
 import datetime
 from decimal import Decimal
+from django.db.models.signals import pre_delete, post_delete
 
 # Create your models here.
 class BuyableType(models.Model):
@@ -31,18 +32,6 @@ class Buyable(models.Model):
 		""" Returns True if the item has deposit. """
 		return self.deposit > Decimal(0)
 	
-	def createPurchase(self, isDeposit=False):
-		""" Creates a :class:`Purchase` containing this :class:`Buyable`. """
-		p = Purchase()
-		if isDeposit:
-			p.price = self.deposit
-		else:
-			p.price = self.price
-		p.dateTime = datetime.datetime.now()
-		p.buyable = self
-		
-		return p
-	
 	def __unicode__(self):
 		item = "%s (%.2f EUR" % (self.name, self.price)
 		if self.hasDeposit():
@@ -59,30 +48,19 @@ class Buyable(models.Model):
 class Order(models.Model):
 	""" Represents an order by the user, consists of several :class:`Purchases <Purchase>`. """
 	user = models.ForeignKey(User)
-	price = models.DecimalField(max_digits=8, decimal_places=2)
-	dateTime = models.DateTimeField()
-
-	def create(self, user=None):
-		models.Model.__init__(self)
-		self.price = Decimal(0)
-		self.dateTime = datetime.datetime.now()
-		if user:
-			self.user = user
+	price = models.DecimalField(max_digits=8, decimal_places=2, default=Decimal(0))
+	dateTime = models.DateTimeField(auto_now_add=True)
 	
 	def addItems(self, items):
 		for item in items:
 			self.purchase.add(item)
 			self.price += item.price
 	
-	def updatePrice(self, commit=False, updateBalance=False):
-		self.price = Decimal(0)
-		for item in self.purchase_set.all():
-			self.price += item.price
-		if commit or updateBalance:
-			# TROLL MODE ON!
-			profile = self.user.get_profile()
-			profile.balance -= self.price
-			profile.save()
+	def updatePrice(self, instance, price, saveOrder=True):
+		""" Update price of order, save Order if saveOrder is True. """
+		self.price += price
+		if self.id and saveOrder:
+			self.save()
 	
 	def __unicode__(self):
 		return "Price %s, User %s" % (self.price, self.user)
@@ -93,39 +71,85 @@ class Order(models.Model):
 			l += item.buyable.name + u", "
 		return l.rstrip(u", ")
 	
-	#def save(self, *args, **kwargs):
-		#profile = self.user.get_profile()
-		#if self.id == None:
-			## new item, get it!
-			#profile.balance -= self.price
-			#profile.save()
-		#else:
-			## get old 
-		#super(Order, self).save(*args, **kwargs)
+	def save(self, *args, **kwargs):
+		profile = self.user.get_profile()
+		if self.id == None:
+			# new item, get it!
+			profile.balance -= self.price
+			profile.save()
+		else:
+			# get old
+			oldobj = Order.objects.get(id=self.id)
+			if oldobj.user == self.user:
+				profile = self.user.get_profile()
+				profile.balance -= (self.price - oldobj.price)
+				profile.save()
+			else:
+				oldProfile = oldobj.user.get_profile()
+				newProfile = self.user.get_profile()
+				oldProfile.balance += oldobj.price
+				oldProfile.save()
+				newprofile.balance -= self.price
+				self.save()
+		super(Order, self).save(*args, **kwargs)
 	
+	@staticmethod
+	def pre_delete_signal(sender, instance, **kwargs):
+		# Normally we would not need this function as for consistency
+		# reasons and the behaviour of Buyables delete at deletion
+		# the orders price should be 0. But for the sake of not getting
+		# inconsistent with the users balance in the strangest situations
+		# we will check that here. This means (at least) one extra query
+		# per order deletion, as we don't get the updated object but the one
+		# where all the buyables have not updated the price
+		updOrder = Order.objects.get(id=instance.id)
+		if updOrder.price != Decimal("0"):
+			profile = updOrder.user.get_profile()
+			profile.balance += updOrder.price
+			profile.save()
+
+pre_delete.connect(Order.pre_delete_signal, sender=Order)
 
 class Purchase(models.Model):
-	""" Represents a :class:`Buyable` in a :class:`Order`"""
+	""" Represents a :class:`Buyable` in a :class:`Order`.
+	
+	Could be viewed as 'one bought item' or 'one item on the voucher'."""
 	order = models.ForeignKey(Order)
-	price = models.DecimalField(max_digits=8, decimal_places=2)
+	price = models.DecimalField(max_digits=8, decimal_places=2, default=None)
 	isDeposit = models.BooleanField()
 	buyable = models.ForeignKey(Buyable)
 	
-	@staticmethod
-	def create(order, buyable, isDeposit=False):
-		""" Create a Purchase from a buyable. Still needs to be saved. """
-		p = Purchase()
-		p.order = order
-		p.isDeposit = isDeposit
-		if p.isDeposit:
-			p.price = buyable.deposit
+	def updatePrice(self):
+		if self.isDeposit:
+			self.price = self.buyable.deposit
 		else:
-			p.price = buyable.price
-		p.dateTime = datetime.datetime.now()
-		p.buyable = buyable
-		
-		return p
+			self.price = self.buyable.price
 	
 	def __unicode__(self):
 		return "%s%s" % (self.buyable.name, (self.isDeposit and " (deposit)" or ""))
 
+	def save(self, saveOrder=True, *args, **kwargs):
+		if self.price == None:
+			self.updatePrice()
+		
+		if self.order:
+			if self.id == None:
+				self.order.updatePrice(self, self.price, saveOrder=saveOrder)
+			else:
+				# object exists, update.
+				oldobj = Purchase.objects.get(id=self.id)
+				if oldobj.order == self.order:
+					self.order.updatePrice(self, self.price - oldobj.price, saveOrder=saveOrder)
+				else:
+					oldobj.order.updatePrice(oldobj, -oldobj.price, saveOrder=saveOrder)
+					self.order.updatePrice(self, self.price, saveOrder=saveOrder)
+		super(Purchase, self).save(*args, **kwargs)
+	
+	@staticmethod
+	def pre_delete_signal(sender, instance, **kwargs):
+		# FIXME: For many items this could get very inefficient
+		#        Find workarround!
+		print "pre delete from purchase"
+		instance.order.updatePrice(instance, -instance.price, saveOrder=True)
+
+pre_delete.connect(Purchase.pre_delete_signal, sender=Purchase)

k4ever/buyable/views.py

@@ -47,19 +47,14 @@ def buyItem(request, itemid, buymode=""):
 			"with/deposit"  item and deposit
 			"only/deposit"  only deposit
 	"""
-	order = Order()
-	order.create(user)
+	order = Order(user=request.user)
 	order.save() # for the id!
 	if buymode == "" or buymode == "with/deposit":
-		p = Purchase.create(order, item, isDeposit=False)
-		p.order = order
-		p.save()
-	# TANNEK! if buymode == "with/dopsit" or buymode == "only/deposit":
+		p = Purchase(order=order, buyable=item, isDeposit=False)
+		p.save(saveOrder=False)
 	if buymode == "with/deposit" or buymode == "only/deposit":
-		p = Purchase.create(order, item, isDeposit=True)
-		p.order = order
-		p.save()
-	order.updatePrice(commit=True)
+		p = Purchase(order=order, buyable=item, isDeposit=True)
+		p.save(saveOrder=False)
 	order.save()
 	return HttpResponseRedirect("/store/bought/%s/" % (order.id)) 
 

k4ever/transaction/models.py

@@ -26,11 +26,9 @@ class Transaction(models.Model):
 	amount = models.DecimalField(max_digits=8, decimal_places=2, validators=[validate_notZero])
 	checked = models.BooleanField(default=False)
 	
-	
 	def __unicode__(self):
 		return u"%s for user %s (%s),%schecked" % (self.amount, self.user, self.transactionType, (self.checked and " " or " not "))
 	
-	# TODO: Find out what would happen if parent save/delete does not like us
 	def save(self, *args, **kwargs):
 		profile = self.user.get_profile()
 		if self.id == None: