From e4bf9fd5b98b25bb93fd3bef64c3b511851e6f73 Mon Sep 17 00:00:00 2001
From: Étienne Loks <etienne.loks@iggdrasil.net>
Date: Thu, 26 Apr 2018 13:23:45 +0200
Subject: Wizard: manage keep M2M member for formset with intermediary model

---
 ishtar_common/wizards.py | 56 +++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 43 insertions(+), 13 deletions(-)

(limited to 'ishtar_common/wizards.py')

diff --git a/ishtar_common/wizards.py b/ishtar_common/wizards.py
index 70f3caa19..89a155c1c 100644
--- a/ishtar_common/wizards.py
+++ b/ishtar_common/wizards.py
@@ -835,7 +835,17 @@ class Wizard(NamedUrlWizardView):
                             value, created = model.objects.get_or_create(
                                 **value)
                         else:
-                            value = model.objects.create(**value)
+                            if 'pk' in value and value['pk']:
+                                try:
+                                    instance = model.objects.get(
+                                        pk=value.pop('pk'))
+                                except model.DoesNotExist:
+                                    continue
+                                for k in value:
+                                    setattr(instance, k, value[k])
+                                value = instance
+                            else:
+                                value = model.objects.create(**value)
                         value.save()  # force post_save
                 # check that an item is not add multiple times (forged forms)
                 if value not in related_model.all() and \
@@ -1252,6 +1262,22 @@ class Wizard(NamedUrlWizardView):
                 initial[base_field] = unicode(value)
         return initial
 
+    @staticmethod
+    def _get_vals_for_instanced_init_for_formset(field, child_obj, vals):
+        if hasattr(child_obj, field):
+            value = getattr(child_obj, field)
+            if hasattr(value, 'pk'):
+                value = value.pk
+            if value is not None:
+                vals[field] = unicode(value)
+        elif hasattr(child_obj, field + "s"):
+            # M2M
+            vals.setlist(field, [
+                unicode(v.pk)
+                for v in getattr(child_obj, field + "s").all()
+            ])
+        return vals
+
     def _get_instanced_init_for_formset(self, obj, current_step, c_form):
         """
         Get initial data from an object: formset
@@ -1278,6 +1304,16 @@ class Wizard(NamedUrlWizardView):
         if not through and not obj._meta.ordering:
             query = query.order_by('pk')
 
+        # an intermediary model is used
+        through_fields = []
+        if through and not related.model._meta.auto_created:
+            target_field = getattr(related.model, c_form.form.base_model, None)
+            if target_field:
+                related_model = target_field.field.related_model
+                for field in related_model._meta.get_fields():
+                    through_fields.append(field.name)
+                through_fields.append('pk')
+
         for child_obj in query.all():
             if not keys:
                 break
@@ -1287,18 +1323,12 @@ class Wizard(NamedUrlWizardView):
                 vals[keys[0]] = unicode(child_obj.pk)
             else:
                 for field in keys:
-                    if hasattr(child_obj, field):
-                        value = getattr(child_obj, field)
-                        if hasattr(value, 'pk'):
-                            value = value.pk
-                        if value is not None:
-                            vals[field] = unicode(value)
-                    elif hasattr(child_obj, field + "s"):
-                        # M2M
-                        vals.setlist(field, [
-                            unicode(v.pk)
-                            for v in getattr(child_obj, field + "s").all()
-                        ])
+                    vals = self._get_vals_for_instanced_init_for_formset(
+                        field, child_obj, vals)
+                for field in through_fields:
+                    related_obj = getattr(child_obj, c_form.form.base_model)
+                    vals = self._get_vals_for_instanced_init_for_formset(
+                        field, related_obj, vals)
             if vals:
                 initial.append(vals)
         return initial
-- 
cgit v1.2.3