From d0a5ed3153518fe10c5048e8011612eb12144f5d Mon Sep 17 00:00:00 2001
From: Radomir Dopieralski <openstack@sheep.art.pl>
Date: Tue, 25 Feb 2014 09:45:53 +0100
Subject: [PATCH] Allow redisplay of the workflow from its handle()

Let the handle() method of the workflow raise a ValidationError to
indicate, that the operation failed and the whole workflow has to be
redisplayed for the user to correct the data and try again. It is
assumed that the handle() method will inject the right error messages
in the right steps and fields of the workflow.

This patch also cleans up the logic of the code a little, to make it
easier to read, and replaces the "next" variable that conflicts with
a python build-in with a more descriptive name.

Change-Id: I2fddb5ae8abbff72b8bf8258001a6f61aef3d1ba
Implements: bp/redisplay-workflow-after-handle-error
---
 horizon/workflows/views.py | 48 +++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/horizon/workflows/views.py b/horizon/workflows/views.py
index 1c691e52a4..c2babceaee 100644
--- a/horizon/workflows/views.py
+++ b/horizon/workflows/views.py
@@ -17,6 +17,7 @@
 import copy
 import json
 
+from django import forms
 from django import http
 from django import shortcuts
 from django.views import generic
@@ -183,28 +184,27 @@ class WorkflowView(generic.TemplateView):
                                        validate_step_end)
             return http.HttpResponse(json.dumps(data),
                                      content_type="application/json")
-        if workflow.is_valid():
-            try:
-                success = workflow.finalize()
-            except Exception:
-                success = False
-                exceptions.handle(request)
-            next = self.request.REQUEST.get(workflow.redirect_param_name, None)
-            if success:
-                msg = workflow.format_status_message(workflow.success_message)
-                messages.success(request, msg)
-            else:
-                msg = workflow.format_status_message(workflow.failure_message)
-                messages.error(request, msg)
-
-            if "HTTP_X_HORIZON_ADD_TO_FIELD" in self.request.META:
-                field_id = self.request.META["HTTP_X_HORIZON_ADD_TO_FIELD"]
-                data = [self.get_object_id(workflow.object),
-                        self.get_object_display(workflow.object)]
-                response = http.HttpResponse(json.dumps(data))
-                response["X-Horizon-Add-To-Field"] = field_id
-                return response
-            else:
-                return shortcuts.redirect(next or workflow.get_success_url())
-        else:
+        if not workflow.is_valid():
             return self.render_to_response(context)
+        try:
+            success = workflow.finalize()
+        except forms.ValidationError:
+            return self.render_to_response(context)
+        except Exception:
+            success = False
+            exceptions.handle(request)
+        if success:
+            msg = workflow.format_status_message(workflow.success_message)
+            messages.success(request, msg)
+        else:
+            msg = workflow.format_status_message(workflow.failure_message)
+            messages.error(request, msg)
+        if "HTTP_X_HORIZON_ADD_TO_FIELD" in self.request.META:
+            field_id = self.request.META["HTTP_X_HORIZON_ADD_TO_FIELD"]
+            data = [self.get_object_id(workflow.object),
+                    self.get_object_display(workflow.object)]
+            response = http.HttpResponse(json.dumps(data))
+            response["X-Horizon-Add-To-Field"] = field_id
+            return response
+        next_url = self.request.REQUEST.get(workflow.redirect_param_name, None)
+        return shortcuts.redirect(next_url or workflow.get_success_url())