Autodetect PDF imports on demo endpoint

arkindex/dataimport/api.py

@@ -138,7 +138,7 @@ class DataImportDemo(CorpusACLMixin, CreateAPIView):
         # Get volume, defaults to demo one
         volume_id = self.request.query_params.get('volume')
         filters = {
-            'corpus__in': corpora,
+            'corpus': datafile.corpus,
             'type': ElementType.Volume,
         }
         if volume_id:
@@ -148,15 +148,15 @@ class DataImportDemo(CorpusACLMixin, CreateAPIView):
 
         volume = get_object_or_404(Element, **filters)
 
-        assert self.has_write_access(volume.corpus), \
-            'Corpus is not writable'
+        assert self.has_write_access(volume.corpus), 'Corpus is not writable'
+
+        import_mode = DataImportMode.PDF if datafile.content_type == 'application/pdf' else DataImportMode.Images
 
         # Start the import
-        dataimport = DataImport.objects.create(
+        dataimport = datafile.corpus.imports.create(
             creator=self.request.user,
-            corpus=datafile.corpus,
             state=DataImportState.Configured,
-            mode=DataImportMode.Images,
+            mode=import_mode,
             payload={
                 'volume_id': str(volume.id),
                 'folder_name': 'user-{}-demo'.format(self.request.user.id),