Auto create transformations without arguments

These are created directly from the selection form view.

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

HISTORY.rst

@@ -3,6 +3,8 @@
 - Fix transformation label display in transformation create view.
 - Remove supervisor environment variable expansion.
 - Don't exit GitLab makefile target if the branch to delete doesn't exist.
+- Automatically create transformations from the selection form that
+  doesn't have arguments.
 
 3.3.2 (2019-12-05)
 ==================

mayan/apps/converter/views.py

@@ -255,20 +255,45 @@ class TransformationSelectView(
     template_name = 'appearance/generic_form.html'
 
     def form_valid(self, form):
-        return HttpResponseRedirect(
-            redirect_to=reverse(
-                viewname='converter:transformation_create',
-                kwargs={
-                    'app_label': self.kwargs['app_label'],
-                    'model': self.kwargs['model'],
-                    'object_id': self.kwargs['object_id'],
-                    'layer_name': self.kwargs['layer_name'],
-                    'transformation_name': form.cleaned_data[
-                        'transformation'
-                    ]
-                }
-            )
+        transformation_class = BaseTransformation.get(
+            name=form.cleaned_data['transformation']
         )
+        if transformation_class.arguments:
+            return HttpResponseRedirect(
+                redirect_to=reverse(
+                    viewname='converter:transformation_create',
+                    kwargs={
+                        'app_label': self.kwargs['app_label'],
+                        'model': self.kwargs['model'],
+                        'object_id': self.kwargs['object_id'],
+                        'layer_name': self.kwargs['layer_name'],
+                        'transformation_name': form.cleaned_data[
+                            'transformation'
+                        ]
+                    }
+                )
+            )
+        else:
+            layer = self.layer
+            content_type = self.get_content_type()
+            object_layer, created = ObjectLayer.objects.get_or_create(
+                content_type=content_type, object_id=self.external_object.pk,
+                stored_layer=layer.stored_layer
+            )
+            object_layer.transformations.create(
+                name=form.cleaned_data['transformation']
+            )
+
+            return HttpResponseRedirect(
+                redirect_to=reverse(
+                    viewname='converter:transformation_list', kwargs={
+                        'app_label': self.kwargs['app_label'],
+                        'model': self.kwargs['model'],
+                        'object_id': self.kwargs['object_id'],
+                        'layer_name': self.kwargs['layer_name']
+                    }
+                )
+            )
 
     def get_extra_context(self):
         return {