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