#33680: Documentation example of customising model instance loading has a bug
-------------------------------------+-------------------------------------
               Reporter:  Ali-Toosi  |          Owner:  nobody
                   Type:  Bug        |         Status:  new
              Component:             |        Version:  4.0
  Documentation                      |       Keywords:  documentation,
               Severity:  Normal     |  from_db, model instance loading
           Triage Stage:             |      Has patch:  0
  Unreviewed                         |
    Needs documentation:  0          |    Needs tests:  0
Patch needs improvement:  0          |  Easy pickings:  1
                  UI/UX:  0          |
-------------------------------------+-------------------------------------
 The docs provide an example of how the model instance loading can be
 changed and how `_loaded_values` can be saved for future comparison here:
 https://docs.djangoproject.com/en/4.0/ref/models/instances/

 In this example, it checks if there are any values not loaded from db then
 add them as DEFERRED values so class instantiation would work
 (`cls(*values)`). However, this would mean `values` list has items now
 that do not map to any `field_names` so when at the end of the function,
 we zip them together and store in `_loaded_values`, the code will fail.

 The easiest fix for this is to update the `field_names` too so they would
 1. work and 2. show which fields were not loaded from the db at the time.

-- 
Ticket URL: <https://code.djangoproject.com/ticket/33680>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

-- 
You received this message because you are subscribed to the Google Groups 
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to django-updates+unsubscr...@googlegroups.com.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/django-updates/01070180938cfccb-d8070ec6-67b9-432d-a468-5ece5eb0f256-000000%40eu-central-1.amazonses.com.

Reply via email to