Add sales channels (#1103)

- [x] Data model
- [x] Enforce constraint
- [x] Filter order list
- [x] Set channel on created order
- [x] Products API
- [x] Order API
- [x] Tests
- [x] Filter reports
- [x] Resellers
- [ ] deploy plugins
  - [ ] posbackend
  - [ ] resellers
  - [ ] reports
- [x] Ticketlayouts
- [x] Support in pretixPOS

src/pretix/base/models/fields.py

@@ -0,0 +1,94 @@
+from django.core import exceptions
+from django.db.models import TextField, lookups as builtin_lookups
+from django.utils.translation import gettext_lazy as _
+from rest_framework import serializers
+from rest_framework.exceptions import ValidationError
+
+DELIMITER = "\x1F"
+
+
+class MultiStringField(TextField):
+    default_error_messages = {
+        'delimiter_found': _('No value can contain the delimiter character.')
+    }
+
+    def __init__(self, verbose_name=None, name=None, **kwargs):
+        super().__init__(verbose_name, name, **kwargs)
+
+    def deconstruct(self):
+        name, path, args, kwargs = super().deconstruct()
+        return name, path, args, kwargs
+
+    def to_python(self, value):
+        if isinstance(value, (list, tuple)):
+            return value
+        elif value:
+            return [v for v in value.split(DELIMITER) if v]
+        else:
+            return []
+
+    def get_prep_value(self, value):
+        if isinstance(value, (list, tuple)):
+            return DELIMITER + DELIMITER.join(value) + DELIMITER
+        elif value is None:
+            return ""
+        raise TypeError("Invalid data type passed.")
+
+    def get_prep_lookup(self, lookup_type, value):  # NOQA
+        raise TypeError('Lookups on multi strings are currently not supported.')
+
+    def from_db_value(self, value, expression, connection, context):
+        if value:
+            return [v for v in value.split(DELIMITER) if v]
+        else:
+            return []
+
+    def validate(self, value, model_instance):
+        super().validate(value, model_instance)
+        for l in value:
+            if DELIMITER in l:
+                raise exceptions.ValidationError(
+                    self.error_messages['delimiter_found'],
+                    code='delimiter_found',
+                )
+
+    def get_lookup(self, lookup_name):
+        if lookup_name == 'contains':
+            return MultiStringContains
+        elif lookup_name == 'icontains':
+            return MultiStringIContains
+        raise NotImplementedError(
+            "Lookup '{}' doesn't work with MultiStringField".format(lookup_name),
+        )
+
+
+class MultiStringContains(builtin_lookups.Contains):
+    def process_rhs(self, qn, connection):
+        sql, params = super().process_rhs(qn, connection)
+        params[0] = "%" + DELIMITER + params[0][1:-1] + DELIMITER + "%"
+        return sql, params
+
+
+class MultiStringIContains(builtin_lookups.IContains):
+    def process_rhs(self, qn, connection):
+        sql, params = super().process_rhs(qn, connection)
+        params[0] = "%" + DELIMITER + params[0][1:-1] + DELIMITER + "%"
+        return sql, params
+
+
+class MultiStringSerializer(serializers.Field):
+    def __init__(self, **kwargs):
+        self.allow_blank = kwargs.pop('allow_blank', False)
+        super().__init__(**kwargs)
+
+    def to_representation(self, value):
+        return value
+
+    def to_internal_value(self, data):
+        if isinstance(data, list):
+            return data
+        else:
+            raise ValidationError('Invalid data type.')
+
+
+serializers.ModelSerializer.serializer_field_mapping[MultiStringField] = MultiStringSerializer

src/pretix/base/models/items.py

@@ -17,6 +17,7 @@ from django.utils.timezone import is_naive, make_aware, now
 from django.utils.translation import pgettext_lazy, ugettext_lazy as _
 from i18nfield.fields import I18nCharField, I18nTextField
 
+from pretix.base.models import fields
 from pretix.base.models.base import LoggedModel
 from pretix.base.models.tax import TaxedPrice
 
@@ -195,6 +196,8 @@ class Item(LoggedModel):
     :type original_price: decimal.Decimal
     :param require_approval: If set to ``True``, orders containing this product can only be processed and paid after approved by an administrator
     :type require_approval: bool
+    :param sales_channels: Sales channels this item is available on.
+    :type sales_channels: bool
     """
 
     event = models.ForeignKey(
@@ -329,6 +332,10 @@ class Item(LoggedModel):
         help_text=_('If set, this will be displayed next to the current price to show that the current price is a '
                     'discounted one. This is just a cosmetic setting and will not actually impact pricing.')
     )
+    sales_channels = fields.MultiStringField(
+        verbose_name=_('Sales channels'),
+        default=['web']
+    )
     # !!! Attention: If you add new fields here, also add them to the copying code in
     # pretix/control/forms/item.py if applicable.
 

src/pretix/base/models/orders.py

@@ -94,6 +94,8 @@ class Order(LockModel, LoggedModel):
     :type require_approval: bool
     :param meta_info: Additional meta information on the order, JSON-encoded.
     :type meta_info: str
+    :param sales_channel: Identifier of the sales channel this order was created through.
+    :type sales_channel: str
     """
 
     STATUS_PENDING = "n"
@@ -174,6 +176,7 @@ class Order(LockModel, LoggedModel):
     require_approval = models.BooleanField(
         default=False
     )
+    sales_channel = models.CharField(max_length=190, default="web")
 
     class Meta:
         verbose_name = _("Order")