Expand possibilities for variant conversion

- Ref get_conversion_options

InvenTree/part/models.py

@@ -1861,6 +1861,59 @@ class Part(MPTTModel):
 
         return self.get_descendants(include_self=False)
 
+    @property
+    def can_convert(self):
+        """
+        Check if this Part can be "converted" to a different variant:
+
+        It can be converted if:
+
+        a) It has non-virtual variant parts underneath it
+        b) It has non-virtual template parts above it
+        c) It has non-virtual sibling variants
+
+        """
+
+        return self.get_conversion_options().count() > 0
+
+    def get_conversion_options(self):
+        """
+        Return options for converting this part to a "variant" within the same tree
+
+        a) Variants underneath this one
+        b) Immediate parent
+        c) Siblings
+        """
+
+        parts = []
+
+        # Child parts
+        children = self.get_descendants(include_self=False)
+
+        for child in children:
+            parts.append(child)
+
+        # Immediate parent
+        if self.variant_of:
+            parts.append(self.variant_of)
+
+        siblings = self.get_siblings(include_self=False)
+
+        for sib in siblings:
+            parts.append(sib)
+
+        filtered_parts = Part.objects.filter(pk__in=[part.pk for part in parts])
+
+        # Ensure this part is not in the queryset, somehow
+        filtered_parts = filtered_parts.exclude(pk=self.pk)
+
+        filtered_parts = filtered_parts.filter(
+            active=True,
+            virtual=False,
+        )
+
+        return filtered_parts
+
     def get_related_parts(self):
         """ Return list of tuples for all related parts:
             - first value is PartRelated object

InvenTree/part/templates/part/part_base.html

@@ -102,6 +102,11 @@
         </div>
 
         <div class='info-messages'>
+            {% if part.virtual %}
+            <div class='alert alert-warning alert-block'>
+                {% trans "This is a virtual part" %}
+            </div>
+            {% endif %}
             {% if part.variant_of %}
             <div class='alert alert-info alert-block'>
                 {% object_link 'part-variants' part.variant_of.id part.variant_of.full_name as link %}

InvenTree/stock/templates/stock/item_base.html

@@ -139,7 +139,7 @@
         <div class='btn-group'>
             <button id='stock-edit-actions' title='{% trans "Stock actions" %}' class='btn btn-default dropdown-toggle' type='button' data-toggle='dropdown'><span class='fas fa-tools'></span> <span class='caret'></span></button>
             <ul class='dropdown-menu' role='menu'>
-                {% if item.part.has_variants %}
+                {% if item.part.can_convert %}
                 <li><a href='#' id='stock-convert' title='{% trans "Convert to variant" %}'><span class='fas fa-screwdriver'></span> {% trans "Convert to variant" %}</a></li>
                 {% endif %}
                 {% if roles.stock.add %}

InvenTree/stock/views.py

@@ -1373,7 +1373,7 @@ class StockItemConvert(AjaxUpdateView):
         form = super().get_form()
         item = self.get_object()
 
-        form.fields['part'].queryset = item.part.get_all_variants()
+        form.fields['part'].queryset = item.part.get_conversion_options()
 
         return form