Listing Related Fields in Django ModelAdmin
I'm listing a model in Django's admin via a TabularInline
. Inside this inline, I'd like to use Django's model traversal syntax to list data in other models referenced from this model via foreign keys. e.g.
class MyRelatedModel(models.Model):
name = models.CharField(max_length=50)
created = models.DateField(auto_now_add=True)
other = models.ForeignKey('MyOtherRelatedModel')
class MyOtherRelatedModel(models.Model):
name = models.CharField(max_length=50)
created = models.DateField(auto_now_add=T开发者_高级运维rue)
class MyRelatedModelInline(admin.TabularInline):
model = MyRelatedModel
fields = ['name', 'created', 'other__name']
#readonly_fields = ['name', 'created', 'other__name']
However, the usage of 'other__name' throws the ImproperlyConfigured error:
'MyRelatedModelInline.fields' refers to field 'other__name' that is missing from the form
Is the model traversal syntax not supported in ModelAdmin instances? If it is supported, what am I doing wrong?
EDIT: If I uncomment readonly_fields, the error becomes:
Caught AttributeError while rendering: 'MyMainModelAdmin' object has no attribute '__name__'
As per Roseman's suggestion above, you can display related (one-to-one or many-to-one) data in a readonly manner with Inline admin models. Here's a little example, just to make sure that we are all on the same page. You can see below that there are three ways to achieve your goal (if I understand that goal correctly).
models.py:
class Company(models.Model):
name = models.CharField(max_length=50)
class Employee(models.Model):
name = models.CharField(max_length=50)
company = models.ForeignKey('Company')
car = models.ForeignKey('Car')
def model_callable(self):
return self.car.rego
class Car(models.Model):
rego = models.CharField(max_length=50)
admin.py:
def unbound_callable(emp):
return emp.car.rego
class EmployeeInline(admin.TabularInline):
model = Employee
fields = ('name', 'model_callable', 'model_admin_callable', unbound_callable)
readonly_fields = ('model_callable', 'model_admin_callable', unbound_callable)
def model_admin_callable(self, emp):
return emp.car.rego
class CompanyAdmin(admin.ModelAdmin):
model = Company
inlines = (EmployeeInline,)
admin.site.register(Company, CompanyAdmin)
As you can see, 'readonly_fields' is treated in the same manner as 'list_display' as per the Django documentation for contrib.admin (from 1.2 onwards).
In the above example, when you are editing a Company, you will see its employees inlined. Each row will have an employee name in an editable textbox and next to the name you will see a readonly bit of text for the employee's car's rego (emp.car.rego).
Referring to your original question, you wanted to reference the related data as 'other__name'. This won't work. Expressions like other__name
or car__rego
only have special meaning as keyword arguments in filters when running Django queries. For example, when fetching an employee who has a car with a particular rego number:
Employee.objects.filter(car__rego='111')
Hope that helps.
j
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