update api export to allow input session id (#178)

Co-authored-by: lcduong <[email protected]>

src/pretalx/agenda/views/schedule.py

@@ -114,7 +114,10 @@ def get(self, request, *args, **kwargs):
 
         exporter.schedule = self.schedule
         if "-my" in exporter.identifier and self.request.user.id is None:
-            return HttpResponseRedirect(self.request.event.urls.login)
+            if request.GET.get('talks'):
+                exporter.talk_ids = request.GET.get('talks').split(',')
+            else:
+                return HttpResponseRedirect(self.request.event.urls.login)
         favs_talks = SubmissionFavourite.objects.filter(user=self.request.user.id)
         if favs_talks.exists():
             exporter.talk_ids = favs_talks[0].talk_list