Refs #314 -- Read-only REST API (#513)

* initial commit

* API auth

* Hierarchical URLs

* Add session auth

* Strong hierarchy

* Add filters

* Add i18n fields, questions

* More viewsets and serializers

* Ticket download

* Add OrderPosition serializer

* View-level permissions

* More tests

* More tests

* Add basic API docs

* Add REST API to docs frontpage

* Tests for order endpoints

* Add invoice tests

* Voucher and waitinglist tests

* Doc draft

* order docs

* Docs on all viewsets

* Disable DRF docs, style sphinx, style browsable API

* Fix tests

* deprecated imports

* Test foo

* Attendee names

* Fix migration problems

* Remove browsable API, plugin integration

* Doc fixes

src/pretix/api/serializers/item.py

@@ -0,0 +1,64 @@
+from rest_framework import serializers
+
+from pretix.api.serializers.i18n import I18nAwareModelSerializer
+from pretix.base.models import (
+    Item, ItemAddOn, ItemCategory, ItemVariation, Question, QuestionOption,
+    Quota,
+)
+
+
+class InlineItemVariationSerializer(I18nAwareModelSerializer):
+    class Meta:
+        model = ItemVariation
+        fields = ('id', 'value', 'active', 'description',
+                  'position', 'default_price', 'price')
+
+
+class InlineItemAddOnSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ItemAddOn
+        fields = ('addon_category', 'min_count', 'max_count',
+                  'position')
+
+
+class ItemSerializer(I18nAwareModelSerializer):
+    addons = InlineItemAddOnSerializer(many=True)
+    variations = InlineItemVariationSerializer(many=True)
+
+    class Meta:
+        model = Item
+        fields = ('id', 'category', 'name', 'active', 'description',
+                  'default_price', 'free_price', 'tax_rate', 'admission',
+                  'position', 'picture', 'available_from', 'available_until',
+                  'require_voucher', 'hide_without_voucher', 'allow_cancel',
+                  'min_per_order', 'max_per_order', 'has_variations',
+                  'variations', 'addons')
+
+
+class ItemCategorySerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = ItemCategory
+        fields = ('id', 'name', 'description', 'position', 'is_addon')
+
+
+class InlineQuestionOptionSerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = QuestionOption
+        fields = ('id', 'answer')
+
+
+class QuestionSerializer(I18nAwareModelSerializer):
+    options = InlineQuestionOptionSerializer(many=True)
+
+    class Meta:
+        model = Question
+        fields = ('id', 'question', 'type', 'required', 'items', 'options', 'position')
+
+
+class QuotaSerializer(I18nAwareModelSerializer):
+
+    class Meta:
+        model = Quota
+        fields = ('id', 'name', 'size', 'items', 'variations')