Add generic method for retriving GET or POST params

InvenTree/InvenTree/views.py

@@ -69,6 +69,22 @@ class AjaxMixin(object):
     ajax_form_action = ''
     ajax_form_title = ''
 
+    def get_param(self, name, method='GET'):
+        """ Get a request query parameter value from URL e.g. ?part=3
+
+        Args:
+            name: Variable name e.g. 'part'
+            method: Request type ('GET' or 'POST')
+
+        Returns:
+            Value of the supplier parameter or None if parameter is not available
+        """
+
+        if method == 'POST':
+            return self.request.POST.get(name, None)
+        else:
+            return self.request.GET.get(name, None)
+
     def get_data(self):
         """ Get extra context data (default implementation is empty dict)
 

InvenTree/part/forms.py

@@ -92,6 +92,8 @@ class EditBomItemForm(HelperForm):
             'quantity',
             'note'
         ]
+
+        # Prevent editing of the part associated with this BomItem
         widgets = {'part': forms.HiddenInput()}
 
 

InvenTree/part/views.py

@@ -406,6 +406,7 @@ class SupplierPartCreate(AjaxCreateView):
     ajax_form_title = 'Create new Supplier Part'
     context_object_name = 'part'
 
+
     def get_initial(self):
         """ Provide initial data for new SupplierPart:
 
@@ -414,18 +415,21 @@ class SupplierPartCreate(AjaxCreateView):
         """
         initials = super(SupplierPartCreate, self).get_initial().copy()
 
-        supplier_id = self.request.GET.get('supplier', None)
-        part_id = self.request.GET.get('part', None)
+        supplier_id = self.get_param('supplier')
+        part_id = self.get_param('part')
 
         if supplier_id:
-            initials['supplier'] = get_object_or_404(Company, pk=supplier_id)
-            # TODO
-            # self.fields['supplier'].disabled = True
+            try:
+                initials['supplier'] = Company.objects.get(pk=supplier_id)
+            except Company.DoesNotExist:
+                initials['supplier'] = None
+        
         if part_id:
-            initials['part'] = get_object_or_404(Part, pk=part_id)
-            # TODO
-            # self.fields['part'].disabled = True
-
+            try:
+                initials['part'] = Part.objects.get(pk=part_id)
+            except Part.DoesNotExist:
+                initials['part'] = None
+        
         return initials