Added a basic framework for data exporters

doc/development/api/exporter.rst

@@ -0,0 +1,59 @@
+.. highlight:: python
+   :linenothreshold: 5
+
+Writing an exporter plugin
+==========================
+
+An is a method to export the product and order data in pretix for later use in another
+context.
+
+In this document, we will walk through the creation of an exporter output plugin. This
+is very similar to creating a payment provider.
+
+Please read :ref:`Creating a plugin <pluginsetup>` first, if you haven't already.
+
+Exporter registration
+---------------------
+
+The exporter API does not make a lot of usage from signals, however, it does use a signal to get a list of
+all available exporters. Your plugin should listen for this signal and return the subclass of
+``pretix.base.exporter.BaseExporter``
+that we'll soon create::
+
+    from django.dispatch import receiver
+
+    from pretix.base.signals import register_data_exporter
+
+
+    @receiver(register_data_exporter)
+    def register_data_exporter(sender, **kwargs):
+        from .exporter import MyExporter
+        return MyExporter
+
+
+The exporter class
+------------------
+
+.. class:: pretix.base.exporter.BaseExporter
+
+   The central object of each exporter is the subclass of ``BaseExporter`` we already mentioned above.
+   In this section, we will discuss it's interface in detail.
+
+   .. py:attribute:: BaseExporter.event
+
+      The default constructor sets this property to the event we are currently
+      working for.
+
+   .. autoattribute:: identifier
+
+      This is an abstract attribute, you **must** override this!
+
+   .. autoattribute:: verbose_name
+
+      This is an abstract attribute, you **must** override this!
+
+   .. autoattribute:: export_form_fields
+
+   .. automethod:: render
+
+      This is an abstract method, you **must** override this!

doc/development/api/index.rst

@@ -10,4 +10,5 @@ Contents:
    restriction
    payment
    ticketoutput
+   exporter
    general

src/pretix/base/__init__.py

@@ -5,4 +5,8 @@ class PretixBaseConfig(AppConfig):
     name = 'pretix.base'
     label = 'pretixbase'
 
+    def ready(self):
+        from . import exporter  # NOQA
+        from . import payment  # NOQA
+
 default_app_config = 'pretix.base.PretixBaseConfig'

src/pretix/base/exporter.py

@@ -0,0 +1,70 @@
+from django import forms
+from django.dispatch import receiver
+from django.http import HttpRequest, HttpResponse, JsonResponse
+
+from pretix.base.signals import register_data_exporters
+
+
+class BaseExporter:
+    """
+    This is the base class for all data exporters
+    """
+
+    def __init__(self, event):
+        self.event = event
+
+    def __str__(self):
+        return self.identifier
+
+    @property
+    def verbose_name(self) -> str:
+        """
+        A human-readable name for this exporter. This should be short but
+        self-explaining. Good examples include 'JSON' or 'Microsoft Excel'.
+        """
+        raise NotImplementedError()  # NOQA
+
+    @property
+    def identifier(self) -> str:
+        """
+        A short and unique identifier for this exporter.
+        This should only contain lowercase letters and in most
+        cases will be the same as your packagename.
+        """
+        raise NotImplementedError()  # NOQA
+
+    @property
+    def export_form_fields(self) -> dict:
+        """
+        When the event's administrator administrator visits the export page, this method
+        is called to return the configuration fields available.
+
+        It should therefore return a dictionary where the keys should be field names and
+        the values should be corresponding Django form fields.
+
+        We suggest that you return an ``OrderedDict`` object instead of a dictionary.
+        Your implementation could look like this::
+
+            @property
+            def export_form_fields(self):
+                return OrderedDict(
+                    [
+                        ('tab_width',
+                         forms.IntegerField(
+                             label=_('Tab width'),
+                             default=4
+                         ))
+                    ]
+                )
+        """
+        return {}
+
+    def render(self, request: HttpRequest) -> HttpResponse:
+        """
+        Render the exported file and return a request that either contains the file
+        or redirects to it.
+
+        :type request: HttpRequest
+        :param request: The HTTP request of the user requesting the export
+        """
+        raise NotImplementedError()  # NOQA

src/pretix/base/plugins.py

@@ -10,6 +10,7 @@ class PluginType(Enum):
     RESTRICTION = 1
     PAYMENT = 2
     ADMINFEATURE = 3
+    EXPORT = 4
 
 
 def get_all_plugins() -> "List[class]":

src/pretix/base/signals.py

@@ -69,3 +69,11 @@ subclass of pretix.base.ticketoutput.BaseTicketOutput
 register_ticket_outputs = EventPluginSignal(
     providing_args=[]
 )
+
+"""
+This signal is sent out to get all known data exporters. Receivers should return a
+subclass of pretix.base.exporter.BaseExporter
+"""
+register_data_exporters = EventPluginSignal(
+    providing_args=[]
+)

src/pretix/control/templates/pretixcontrol/event/base.html

@@ -114,6 +114,12 @@
                         {% trans "Overview" %}
                     </a>
                 </li>
+                <li>
+                    <a href="{% url 'control:event.orders.export' organizer=request.event.organizer.slug event=request.event.slug %}"
+                       {% if url_name == "event.orders.export" %}class="active"{% endif %}>
+                        {% trans "Export" %}
+                    </a>
+                </li>
             </ul>
         </li>
     {% endif %}

src/pretix/control/templates/pretixcontrol/orders/export.html

@@ -0,0 +1,25 @@
+{% extends "pretixcontrol/event/base.html" %}
+{% load i18n %}
+{% load bootstrap3 %}
+{% load order_overview %}
+{% block title %}{% trans "Data export" %}{% endblock %}
+{% block content %}
+	<h1>{% trans "Data export" %}</h1>
+    {% for e in exporters %}
+        <div class="panel panel-default">
+            <div class="panel-heading">
+                <h3 class="panel-title">{{ e.verbose_name }}</h3>
+            </div>
+            <div class="panel-body">
+                <form action="" method="post" class="form-horizontal">
+                    {% csrf_token %}
+                    <input type="hidden" name="exporter" value="{{ e.identifier }}" />
+                    {% bootstrap_form e.form layout='horizontal' %}
+                    <button class="btn btn-primary pull-right" type="submit">
+                        <span class="icon icon-upload"></span> {% trans "Start export" %}
+                    </button>
+                </form>
+            </div>
+        </div>
+    {% endfor %}
+{% endblock %}

src/pretix/control/urls.py

@@ -65,6 +65,7 @@ urlpatterns = [
             name='event.order.extend'),
         url(r'^orders/(?P<code>[0-9A-Z]+)/$', orders.OrderDetail.as_view(), name='event.order'),
         url(r'^orders/overview/$', orders.OverView.as_view(), name='event.orders.overview'),
+        url(r'^orders/export/$', orders.ExportView.as_view(), name='event.orders.export'),
         url(r'^orders/go$', orders.OrderGo.as_view(), name='event.orders.go'),
         url(r'^orders/$', orders.OrderList.as_view(), name='event.orders'),
     ])),

src/pretix/control/views/orders.py

@@ -1,5 +1,6 @@
 from itertools import groupby
 
+from django import forms
 from django.contrib import messages
 from django.db.models import Q, Count, Sum
 from django.http import HttpResponse
@@ -11,7 +12,9 @@ from django.views.generic import DetailView, ListView, TemplateView, View
 
 from pretix.base.models import Item, ItemCategory, Order, OrderPosition, Quota
 from pretix.base.services.orders import mark_order_paid
-from pretix.base.signals import register_payment_providers
+from pretix.base.signals import (
+    register_data_exporters, register_payment_providers,
+)
 from pretix.control.forms.orders import ExtendForm
 from pretix.control.permissions import EventPermissionRequiredMixin
 
@@ -325,3 +328,45 @@ class OrderGo(EventPermissionRequiredMixin, View):
         except Order.DoesNotExist:
             messages.error(request, _('There is no order with the given order code.'))
             return redirect('control:event.orders', event=request.event.slug, organizer=request.event.organizer.slug)
+
+
+class ExportView(EventPermissionRequiredMixin, TemplateView):
+    permission = 'can_view_orders'
+    template_name = 'pretixcontrol/orders/export.html'
+
+    @cached_property
+    def exporters(self):
+        exporters = []
+        responses = register_data_exporters.send(self.request.event)
+        for receiver, response in responses:
+            ex = response(self.request.event)
+            ex.form = forms.Form(
+                data=(self.request.POST if self.request.method == 'POST' else None)
+            )
+            ex.form.fields = ex.export_form_fields
+            exporters.append(ex)
+        return exporters
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        ctx['exporters'] = self.exporters
+        return ctx
+
+    @cached_property
+    def exporter(self):
+        for ex in self.exporters:
+            if ex.identifier == self.request.POST.get("exporter"):
+                return ex
+
+    def post(self, *args, **kwargs):
+        if not self.exporter:
+            messages.error(self.request, _('The selected exporter was not found.'))
+            return redirect('control:event.orders.export', kwargs={
+                'event': self.request.event.slug,
+                'organizer': self.request.event.organizer.slug
+            })
+        if not self.exporter.form.is_valid():
+            messages.error(self.request, _('There was a problem processing your input. See below for error details.'))
+            return self.get(*args, **kwargs)
+
+        return self.exporter.render(self.request)