Fixed #106 -- added pay-what-you-want tickets

src/pretix/base/migrations/0017_auto_20160324_1615.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.2 on 2016-03-24 16:15
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0016_voucher_variation'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='logentry',
+            options={'ordering': ('-datetime',)},
+        ),
+        migrations.AddField(
+            model_name='item',
+            name='free_price',
+            field=models.BooleanField(default=False, help_text='If this option is active, your users can choose the price themselves. The price configured above is then interpreted as the minimum price a user has to enter. You could use this e.g. to collect additional donations for your event.', verbose_name='Free price'),
+        ),
+    ]

src/pretix/base/models/items.py

@@ -3,7 +3,7 @@ from datetime import datetime
 from decimal import Decimal
 
 from django.db import models
-from django.db.models import Q, Case, Count, Sum, When
+from django.db.models import Q
 from django.utils.functional import cached_property
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
@@ -132,6 +132,13 @@ class Item(LoggedModel):
         verbose_name=_("Default price"),
         max_digits=7, decimal_places=2, null=True
     )
+    free_price = models.BooleanField(
+        default=False,
+        verbose_name=_("Free price input"),
+        help_text=_("If this option is active, your users can choose the price themselves. The price configured above "
+                    "is then interpreted as the minimum price a user has to enter. You could use this e.g. to collect "
+                    "additional donations for your event.")
+    )
     tax_rate = models.DecimalField(
         verbose_name=_("Taxes included in percent"),
         max_digits=7, decimal_places=2,

src/pretix/base/services/cart.py

@@ -1,4 +1,5 @@
 from datetime import datetime, timedelta
+from decimal import Decimal
 
 from django.conf import settings
 from django.db.models import Q
@@ -51,7 +52,7 @@ def _re_add_expired_positions(items: List[CartPosition], event: Event, cart_id:
         Q(cart_id=cart_id) & Q(event=event) & Q(expires__lte=now())
     )
     for cp in expired:
-        items.insert(0, (cp.item_id, cp.variation_id, 1, cp))
+        items.insert(0, (cp.item_id, cp.variation_id, 1, cp.price, cp))
         positions.add(cp)
     return positions
 
@@ -69,7 +70,7 @@ def _check_date(event: Event) -> None:
         raise CartError(error_messages['ended'])
 
 
-def _add_new_items(event: Event, items: List[Tuple[int, Optional[int], int]],
+def _add_new_items(event: Event, items: List[Tuple[int, Optional[int], int, Optional[str]]],
                    cart_id: str, expiry: datetime) -> Optional[str]:
     err = None
 
@@ -114,20 +115,24 @@ def _add_new_items(event: Event, items: List[Tuple[int, Optional[int], int]],
                     err = err or error_messages['in_part']
                 quota_ok = min(quota_ok, avail[1])
 
+        price = item.default_price if variation is None else (
+            variation.default_price if variation.default_price is not None else item.default_price)
+        if item.free_price and len(i) > 3 and i[3]:
+            custom_price = Decimal(i[3].replace(",", "."))
+            price = max(custom_price, price)
+
         # Create a CartPosition for as much items as we can
         for k in range(quota_ok):
-            if len(i) > 3 and i[2] == 1:
+            if len(i) > 4 and i[2] == 1:
                 # Recreating
-                cp = i[3]
+                cp = i[4]
                 cp.expires = expiry
-                cp.price = item.default_price if variation is None else (
-                    variation.default_price if variation.default_price is not None else item.default_price)
+                cp.price = price
                 cp.save()
             else:
                 CartPosition.objects.create(
                     event=event, item=item, variation=variation,
-                    price=item.default_price if variation is None else (
-                        variation.default_price if variation.default_price is not None else item.default_price),
+                    price=price,
                     expires=expiry,
                     cart_id=cart_id
                 )
@@ -161,7 +166,7 @@ def _add_voucher(event: Event, voucher: str, expiry: datetime, cart_id: str):
         raise CartError(error_messages['voucher_invalid'])
 
 
-def _add_items_to_cart(event: Event, items: List[Tuple[int, Optional[int], int]], cart_id: str=None,
+def _add_items_to_cart(event: Event, items: List[Tuple[int, Optional[int], int, Optional[str]]], cart_id: str=None,
                        voucher: str=None) -> None:
     with event.lock():
         _check_date(event)
@@ -186,12 +191,12 @@ def _add_items_to_cart(event: Event, items: List[Tuple[int, Optional[int], int]]
             _add_voucher(event, voucher, expiry, cart_id)
 
 
-def add_items_to_cart(event: int, items: List[Tuple[int, Optional[int], int]], cart_id: str=None,
+def add_items_to_cart(event: int, items: List[Tuple[int, Optional[int], int, Optional[str]]], cart_id: str=None,
                       voucher: str=None) -> None:
     """
     Adds a list of items to a user's cart.
     :param event: The event ID in question
-    :param items: A list of tuple of the form (item id, variation id or None, number)
+    :param items: A list of tuple of the form (item id, variation id or None, number, custom_price)
     :param session: Session ID of a guest
     :param coupon: A coupon that should also be reeemed
     :raises CartError: On any error that occured
@@ -203,19 +208,29 @@ def add_items_to_cart(event: int, items: List[Tuple[int, Optional[int], int]], c
         raise CartError(error_messages['busy'])
 
 
-def _remove_items_from_cart(event: int, items: List[Tuple[int, Optional[int], int]], cart_id: str) -> None:
+def _remove_items_from_cart(event: int, items: List[Tuple[int, Optional[int], int, Optional[str]]],
+                            cart_id: str) -> None:
     with event.lock():
-        for item, variation, cnt in items:
+        for item, variation, cnt, price in items:
             cw = Q(cart_id=cart_id) & Q(item_id=item) & Q(event=event)
             if variation:
                 cw &= Q(variation_id=variation)
             else:
                 cw &= Q(variation__isnull=True)
-            for cp in CartPosition.objects.filter(cw).order_by("-price")[:cnt]:
-                cp.delete()
+            # Prefer to delete positions that have the same price as the one the user clicked on, after thet
+            # prefer the most expensive ones.
+            if price:
+                correctprice = CartPosition.objects.filter(cw).filter(price=Decimal(price.replace(",", ".")))[:cnt]
+                for cp in correctprice:
+                    cp.delete()
+                cnt -= len(correctprice)
+            if cnt > 0:
+                for cp in CartPosition.objects.filter(cw).order_by("-price")[:cnt]:
+                    cp.delete()
 
 
-def remove_items_from_cart(event: int, items: List[Tuple[int, Optional[int], int]], cart_id: str=None) -> None:
+def remove_items_from_cart(event: int, items: List[Tuple[int, Optional[int], int, Optional[str]]],
+                           cart_id: str=None) -> None:
     """
     Removes a list of items from a user's cart.
     :param event: The event ID in question
@@ -233,8 +248,8 @@ if settings.HAS_CELERY:
     from pretix.celery import app
 
     @app.task(bind=True, max_retries=5, default_retry_delay=1)
-    def add_items_to_cart_task(self, event: int, items: List[Tuple[int, Optional[int], int]], cart_id: str,
-                               voucher: str=None):
+    def add_items_to_cart_task(self, event: int, items: List[Tuple[int, Optional[int], int, Optional[str]]],
+                               cart_id: str, voucher: str=None):
         event = Event.objects.get(id=event)
         try:
             try:
@@ -245,7 +260,8 @@ if settings.HAS_CELERY:
             return e
 
     @app.task(bind=True, max_retries=5, default_retry_delay=1)
-    def remove_items_from_cart_task(self, event: int, items: List[Tuple[int, Optional[int], int]], cart_id: str):
+    def remove_items_from_cart_task(self, event: int, items: List[Tuple[int, Optional[int], int]],
+                                    cart_id: str):
         event = Event.objects.get(id=event)
         try:
             try:

src/pretix/base/services/orders.py

@@ -189,7 +189,7 @@ def _check_positions(event: Event, dt: datetime, positions: List[CartPosition]):
             if cp.voucher.price is not None:
                 price = cp.voucher.price
 
-        if price != cp.price:
+        if price != cp.price and not (cp.item.free_price and cp.price > price):
             positions[i] = cp
             cp.price = price
             cp.save()

src/pretix/control/forms/item.py

@@ -95,6 +95,7 @@ class ItemFormGeneral(I18nModelForm):
             'description',
             'picture',
             'default_price',
+            'free_price',
             'tax_rate',
             'available_from',
             'available_until',

src/pretix/control/templates/pretixcontrol/item/index.html

@@ -2,34 +2,35 @@
 {% load i18n %}
 {% load bootstrap3 %}
 {% block inside %}
-	<form action="" method="post" class="form-horizontal" enctype="multipart/form-data">
-		{% csrf_token %}
-		<fieldset>
-			<legend>{% trans "General information" %}</legend>
-			{% bootstrap_field form.name layout="horizontal" %}
-			{% bootstrap_field form.active layout="horizontal" %}
+    <form action="" method="post" class="form-horizontal" enctype="multipart/form-data">
+        {% csrf_token %}
+        <fieldset>
+            <legend>{% trans "General information" %}</legend>
+            {% bootstrap_field form.name layout="horizontal" %}
+            {% bootstrap_field form.active layout="horizontal" %}
             {% if form.has_variations %}
                 {% bootstrap_field form.has_variations layout="horizontal" %}
             {% endif %}
-			{% bootstrap_field form.category layout="horizontal" %}
+            {% bootstrap_field form.category layout="horizontal" %}
             {% bootstrap_field form.admission layout="horizontal" %}
-			{% bootstrap_field form.description layout="horizontal" %}
+            {% bootstrap_field form.description layout="horizontal" %}
             {% bootstrap_field form.picture layout="horizontal" %}
-		</fieldset>
-		<fieldset>
-			<legend>{% trans "Price settings" %}</legend>
-			{% bootstrap_field form.default_price layout="horizontal" %}
-			{% bootstrap_field form.tax_rate layout="horizontal" %}
-		</fieldset>
-		<fieldset>
-			<legend>{% trans "Availability" %}</legend>
-			{% bootstrap_field form.available_from layout="horizontal" %}
-			{% bootstrap_field form.available_until layout="horizontal" %}
-		</fieldset>
-		<div class="form-group submit-group">
+        </fieldset>
+        <fieldset>
+            <legend>{% trans "Price settings" %}</legend>
+            {% bootstrap_field form.default_price layout="horizontal" %}
+            {% bootstrap_field form.tax_rate layout="horizontal" %}
+            {% bootstrap_field form.free_price layout="horizontal" %}
+        </fieldset>
+        <fieldset>
+            <legend>{% trans "Availability" %}</legend>
+            {% bootstrap_field form.available_from layout="horizontal" %}
+            {% bootstrap_field form.available_until layout="horizontal" %}
+        </fieldset>
+        <div class="form-group submit-group">
             <button type="submit" class="btn btn-primary btn-save">
                 {% trans "Save" %}
             </button>
-		</div>
-	</form>
+        </div>
+    </form>
 {% endblock %}

src/pretix/presale/templates/pretixpresale/event/fragment_cart.html

@@ -28,12 +28,17 @@
             <form action="{% eventurl event "presale:event.cart.remove" %}"
                     method="post" data-asynctask>
                 {% csrf_token %}
+
                 {% if line.variation %}
                     <input type="hidden" name="variation_{{ line.item.id }}_{{ line.variation.id }}"
                             value="1" />
+                    <input type="hidden" name="price_{{ line.item.id }}_{{ line.variation.id }}"
+                            value="{{ line.price }}" />
                 {% else %}
                     <input type="hidden" name="item_{{ line.item.id }}"
                             value="1" />
+                    <input type="hidden" name="price_{{ line.item.id }}"
+                            value="{{ line.price }}" />
                 {% endif %}
                 <button class="btn btn-mini btn-link"><i class="fa fa-minus"></i></button>
             </form>
@@ -46,9 +51,13 @@
                 {% if line.variation %}
                     <input type="hidden" name="variation_{{ line.item.id }}_{{ line.variation.id }}"
                         value="1" />
+                    <input type="hidden" name="price_{{ line.item.id }}_{{ line.variation.id }}"
+                            value="{{ line.price }}" />
                 {% else %}
                     <input type="hidden" name="item_{{ line.item.id }}"
                             value="1" />
+                    <input type="hidden" name="price_{{ line.item.id }}"
+                            value="{{ line.price }}" />
                 {% endif %}
                 <button class="btn btn-mini btn-link"><i class="fa fa-plus"></i></button>
             </form>

src/pretix/presale/templates/pretixpresale/event/index.html

@@ -76,7 +76,7 @@
                                         {% if item.description %}<p>{{ item.description }}</p>{% endif %}
                                     </div>
                                     <div class="col-md-2 col-xs-6 price">
-                                        {% if item.min_price != item.max_price %}
+                                        {% if item.min_price != item.max_price or item.free_price %}
                                             {% blocktrans trimmed with minprice=item.min_price|floatformat:2 currency=event.currency %}
                                                 from {{ currency }} {{ minprice }}
                                             {% endblocktrans %}
@@ -101,7 +101,18 @@
                                                 {% endif %}
                                             </div>
                                             <div class="col-md-2 col-xs-6 price">
-                                                {{ event.currency }} {{ var.price|floatformat:2 }}
+                                                {% if item.free_price %}
+                                                    <div class="input-group">
+                                                        <span class="input-group-addon">{{ event.currency }}</span>
+                                                        <input type="number" class="form-control input-item-price"
+                                                                placeholder="0"
+                                                                min="{{ var.price|stringformat:"0.2f" }}"
+                                                                name="price_{{ item.id }}_{{ var.id }}"
+                                                                step="0.01" value="{{ var.price|stringformat:"0.2f" }}">
+                                                    </div>
+                                                {% else %}
+                                                    {{ event.currency }} {{ var.price|floatformat:2 }}
+                                                {% endif %}
                                                 {% if item.tax_rate %}
                                                     <br/>
                                                     <small>{% blocktrans trimmed with rate=item.tax_rate %}
@@ -135,13 +146,24 @@
                                         </a>
                                     {% endif %}
                                     <strong>{{ item.name }}</strong>
-                                    {% if item.description %}<p class="description">{{ item.description }}</p>{% endif %}
+                                    {% if item.description %}
+                                        <p class="description">{{ item.description }}</p>{% endif %}
                                     {% if event.settings.show_quota_left %}
                                         {% include "pretixpresale/event/fragment_quota_left.html" with avail=item.cached_availability %}
                                     {% endif %}
                                 </div>
                                 <div class="col-md-2 col-xs-6 price">
-                                    {{ event.currency }} {{ item.price|floatformat:2 }}
+                                    {% if item.free_price %}
+                                        <div class="input-group">
+                                            <span class="input-group-addon">{{ event.currency }}</span>
+                                            <input type="number" class="form-control input-item-price" placeholder="0"
+                                                    min="{{ item.price|stringformat:"0.2f" }}"
+                                                    name="price_{{ item.id }}"
+                                                    step="0.01" value="{{ item.price|stringformat:"0.2f" }}">
+                                        </div>
+                                    {% else %}
+                                        {{ event.currency }} {{ item.price|floatformat:2 }}
+                                    {% endif %}
                                     {% if item.tax_rate %}
                                         <br/>
                                         <small>{% blocktrans trimmed with rate=item.tax_rate %}

src/pretix/presale/views/cart.py

@@ -33,17 +33,19 @@ class CartActionMixin:
         """
         items = []
         for key, value in self.request.POST.items():
-            if value.strip() == '':
+            if value.strip() == '' or '_' not in key:
                 continue
+
+            price = self.request.POST.get('price_' + key.split("_", 1)[1], "")
             if key.startswith('item_'):
                 try:
-                    items.append((int(key.split("_")[1]), None, int(value)))
+                    items.append((int(key.split("_")[1]), None, int(value), price))
                 except ValueError:
                     messages.error(self.request, _('Please enter numbers only.'))
                     return []
             elif key.startswith('variation_'):
                 try:
-                    items.append((int(key.split("_")[1]), int(key.split("_")[2]), int(value)))
+                    items.append((int(key.split("_")[1]), int(key.split("_")[2]), int(value), price))
                 except ValueError:
                     messages.error(self.request, _('Please enter numbers only.'))
                     return []

src/static/pretixpresale/less/event.less

@@ -10,6 +10,9 @@
     .input-item-count {
         text-align: center;
     }
+    .input-item-price {
+        text-align: right;
+    }
     .availability-box {
         text-align: center;
 

src/tests/presale/test_cart.py

@@ -57,6 +57,66 @@ class CartTest(CartTestMixin, TestCase):
         self.assertIsNone(objs[0].variation)
         self.assertEqual(objs[0].price, 23)
 
+    def test_free_price(self):
+        self.ticket.free_price = True
+        self.ticket.save()
+        response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            'price_%d' % self.ticket.id: '24.00'
+        }, follow=True)
+        self.assertRedirects(response, '/%s/%s/' % (self.orga.slug, self.event.slug),
+                             target_status_code=200)
+        doc = BeautifulSoup(response.rendered_content)
+        self.assertIn('Early-bird', doc.select('.cart .cart-row')[0].select('strong')[0].text)
+        self.assertIn('1', doc.select('.cart .cart-row')[0].select('.count')[0].text)
+        self.assertIn('24', doc.select('.cart .cart-row')[0].select('.price')[0].text)
+        self.assertIn('24', doc.select('.cart .cart-row')[0].select('.price')[1].text)
+        objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event))
+        self.assertEqual(len(objs), 1)
+        self.assertEqual(objs[0].item, self.ticket)
+        self.assertIsNone(objs[0].variation)
+        self.assertEqual(objs[0].price, 24)
+
+    def test_free_price_only_if_allowed(self):
+        self.ticket.free_price = False
+        self.ticket.save()
+        response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            'price_%d' % self.ticket.id: '24.00'
+        }, follow=True)
+        self.assertRedirects(response, '/%s/%s/' % (self.orga.slug, self.event.slug),
+                             target_status_code=200)
+        doc = BeautifulSoup(response.rendered_content)
+        self.assertIn('Early-bird', doc.select('.cart .cart-row')[0].select('strong')[0].text)
+        self.assertIn('1', doc.select('.cart .cart-row')[0].select('.count')[0].text)
+        self.assertIn('23', doc.select('.cart .cart-row')[0].select('.price')[0].text)
+        self.assertIn('23', doc.select('.cart .cart-row')[0].select('.price')[1].text)
+        objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event))
+        self.assertEqual(len(objs), 1)
+        self.assertEqual(objs[0].item, self.ticket)
+        self.assertIsNone(objs[0].variation)
+        self.assertEqual(objs[0].price, 23)
+
+    def test_free_price_lower_bound(self):
+        self.ticket.free_price = False
+        self.ticket.save()
+        response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'item_%d' % self.ticket.id: '1',
+            'price_%d' % self.ticket.id: '12.00'
+        }, follow=True)
+        self.assertRedirects(response, '/%s/%s/' % (self.orga.slug, self.event.slug),
+                             target_status_code=200)
+        doc = BeautifulSoup(response.rendered_content)
+        self.assertIn('Early-bird', doc.select('.cart .cart-row')[0].select('strong')[0].text)
+        self.assertIn('1', doc.select('.cart .cart-row')[0].select('.count')[0].text)
+        self.assertIn('23', doc.select('.cart .cart-row')[0].select('.price')[0].text)
+        self.assertIn('23', doc.select('.cart .cart-row')[0].select('.price')[1].text)
+        objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event))
+        self.assertEqual(len(objs), 1)
+        self.assertEqual(objs[0].item, self.ticket)
+        self.assertIsNone(objs[0].variation)
+        self.assertEqual(objs[0].price, 23)
+
     def test_variation(self):
         response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
             'variation_%d_%d' % (self.shirt.id, self.shirt_red.id): '1'
@@ -75,6 +135,27 @@ class CartTest(CartTestMixin, TestCase):
         self.assertEqual(objs[0].variation, self.shirt_red)
         self.assertEqual(objs[0].price, 14)
 
+    def test_variation_free_price(self):
+        self.shirt.free_price = True
+        self.shirt.save()
+        response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
+            'variation_%d_%d' % (self.shirt.id, self.shirt_red.id): '1',
+            'price_%d_%d' % (self.shirt.id, self.shirt_red.id): '16',
+        }, follow=True)
+        self.assertRedirects(response, '/%s/%s/' % (self.orga.slug, self.event.slug),
+                             target_status_code=200)
+        doc = BeautifulSoup(response.rendered_content)
+        self.assertIn('Shirt', doc.select('.cart .cart-row')[0].select('strong')[0].text)
+        self.assertIn('Red', doc.select('.cart .cart-row')[0].text)
+        self.assertIn('1', doc.select('.cart .cart-row')[0].select('.count')[0].text)
+        self.assertIn('16', doc.select('.cart .cart-row')[0].select('.price')[0].text)
+        self.assertIn('16', doc.select('.cart .cart-row')[0].select('.price')[1].text)
+        objs = list(CartPosition.objects.filter(cart_id=self.session_key, event=self.event))
+        self.assertEqual(len(objs), 1)
+        self.assertEqual(objs[0].item, self.shirt)
+        self.assertEqual(objs[0].variation, self.shirt_red)
+        self.assertEqual(objs[0].price, 16)
+
     def test_count(self):
         response = self.client.post('/%s/%s/cart/add' % (self.orga.slug, self.event.slug), {
             'item_%d' % self.ticket.id: '2'

src/tests/presale/test_checkout.py

@@ -217,6 +217,23 @@ class CheckoutTestCase(TestCase):
         session[key] = value
         session.save()
 
+    def test_free_price(self):
+        self.ticket.free_price = True
+        self.ticket.save()
+        cr1 = CartPosition.objects.create(
+            event=self.event, cart_id=self.session_key, item=self.ticket,
+            price=42, expires=now() + timedelta(minutes=10)
+        )
+        self._set_session('payment', 'banktransfer')
+
+        response = self.client.post('/%s/%s/checkout/confirm/' % (self.orga.slug, self.event.slug), follow=True)
+        doc = BeautifulSoup(response.rendered_content)
+        self.assertEqual(len(doc.select(".thank-you")), 1)
+        self.assertFalse(CartPosition.objects.filter(id=cr1.id).exists())
+        self.assertEqual(Order.objects.count(), 1)
+        self.assertEqual(OrderPosition.objects.count(), 1)
+        self.assertEqual(OrderPosition.objects.first().price, 42)
+
     def test_confirm_in_time(self):
         cr1 = CartPosition.objects.create(
             event=self.event, cart_id=self.session_key, item=self.ticket,
@@ -260,6 +277,22 @@ class CheckoutTestCase(TestCase):
         cr1 = CartPosition.objects.get(id=cr1.id)
         self.assertEqual(cr1.price, 24)
 
+    def test_confirm_free_price_increased(self):
+        self.ticket.default_price = 24
+        self.ticket.free_price = True
+        self.ticket.save()
+        cr1 = CartPosition.objects.create(
+            event=self.event, cart_id=self.session_key, item=self.ticket,
+            price=23, expires=now() - timedelta(minutes=10)
+        )
+        self._set_session('payment', 'banktransfer')
+
+        response = self.client.post('/%s/%s/checkout/confirm/' % (self.orga.slug, self.event.slug), follow=True)
+        doc = BeautifulSoup(response.rendered_content)
+        self.assertEqual(len(doc.select(".alert-danger")), 1)
+        cr1 = CartPosition.objects.get(id=cr1.id)
+        self.assertEqual(cr1.price, 24)
+
     def test_voucher(self):
         v = Voucher.objects.create(item=self.ticket, price=Decimal('12.00'), event=self.event,
                                    valid_until=now() + timedelta(days=2))