Django 4.2. How can djanjo-admin make a pre-selection of the values of a model field that is a ForeignKey, if it is specified in autocomplete_fields?
The following code works as required, if you comment out the line autocomplete_fields = ('code',). Then there are objects in the drop-down list that have only one of the required types. But if you remove the comment, then all objects are already offered in the autocomplete field, without pre-select.
models.py
class SignalsGuide(models.Model):
TYPE_CHOICES = [
("signals", "Signal"),
("pdata", "Passport value"),
("constants", "Constant"),
("diag", "Diag value"),
]
id = models.BigAutoField(primary_key=True)
code = models.CharField(max_length=100, verbose_name='Code')
type = models.CharField(
max_length=30, choices=TYPE_CHOICES, default="signals",
verbose_name='Signal type')
def __str__(self) -> str:
return self.code
class Params(models.Model):
id = models.BigAutoField(primary_key=True)
code = models.ForeignKey(
'SignalsGuide', models.DO_NOTHING, db_column='code',
verbose_name='Code')
value = models.CharField(
max_length=400, blank=True, null=True, verbose_name='Value')
def __str__(self) -> str:
return f"{self.code.code}: {self.value}"
admin.py
class ParamsAdmin(admin.ModelAdmin):
_param_types = ("pdata", "constants")
list_display = ('id', 'code', 'value')
search_fields = ('id', 'code__code', 'value')
autocomplete_fields = ('code',)
list_select_related = ('code',)
def formfield_for_foreignkey(self, db_field, request, **kwargs):
if db_field.name == "code":
kwargs["queryset"] = SignalsGuide.objects.filter(type__in=self._param_types)
return super().formfield_for_foreignkey(db_field, request, **kwargs)