I'm trying to create editable set of objects.
I have Visitor model, which can contain set of models Sibling. But the set may be blank. This set should be editable in Django admin, and, I would like it will be generated by built-in tools.
Here is my approach to do this:
class Sibling(models.Model):
VisitorID = models.ForeignKey('Visitor')
# ... some fields
class Visitor(models.Model):
# ... some fields
Siblings = models.ManyToManyField(Sibling, blank=True)
It is bad way because there are all Siblings from all Visitors in the auto-generated form in django admin, but I want only those which are related to specific Visitor.
Could anyone help me or give advice?
One way achieve this with a Serializer class
class Sibling(models.Model):
VisitorID = models.ForeignKey('Visitor')
# ... some fields
class Visitor(models.Model):
# ... some fields
class VisitorSerializer(serializers.ModelSerializer):
sibling = serializers.RelatedField(source='sibling')
class Meta:
model = Visitor
# List all fields in Visitor plus sibling
fields = ('id', 'somefieldinvisitormodel', 'sibling')
The serializer class allows you to override what's being displayed in admin without having to mess with your models. This also allows you to remove the extra relationship you added within visitor.
This isn't an entirely automated solution, but it's close.
Related
I am trying to understand the process of generating generic form views in django. I have a generic view class with just
class BookUpdate(UpdateView):
model = Book
fields = [ 'name',
'pages',
'categorys'
]
which automatically generates a working html form from my model data. But now, I want to modify the field that is shown for categorys, is there any way to do this, or do I have to create a complete working BookForm class and custom BookUpdate class? Here its just 3 fields, but in my real case there are maybe 15 fields that I would need to code by myself, just because of a tiny change in the category field.
Cant I just overwrite the single field, using any class method?
You can either specify fields or form_class in your generic class-based view. With fields, Django will use a modelform_factory to generate the form. There's not much you can customise then.
You should create a BookForm class so that you can customise the fields. In your BookUpdate view, you only need to remove fields and add form_class = BookForm. Here I'm customising the widget for categorys and overriding the form field for pages:
def BookUpdate(UpdateView):
model = Book
form_class = BookForm
def BookForm(ModelForm):
pages = MyCustomPagesField()
class Meta:
model = Book
fields = '__all__'
widgets = {'categorys': MyCustomWidget()}
Note that you don't have to specify all fields, you can use "__all__" to have all fields or you can set exclude = [<list fields to exclude>] to just exclude a couple.
You don't have to code the fields yourself. But there is a small amount of work to do, as there isn't a method to override.
What you need to do is define a custom form. Since that will be a ModelForm, it will use the same logic to automatically create its fields based on the model. You can then override the definition of one of them.
class BookForm(forms.ModelForm):
categorys = forms.ModelMultipleChoiceField(custom_attributes_here...)
class Meta:
model = Book
fields = ["name", "pages", "categorys"]
And now tell your view to use that form:
class BookUpdate(UpdateView):
form_class = BookForm
I need use inlines in django admin for show relation between two models but in the moment that i do, i had to do the reverse relationship to show inlines.
Example:
class OtherModel(models.Model):
field1=models...
........
class Model(models.Model)
field1 = models....
other_model = models.ForeignKey(OtherModel)
I create the inline...
class OtherModelInline(admin.StackedInline):
model = OtherModel
extra = 1
#admin.register(Model):
class ModelAdmin(admin.modelAdmin):
inlines = [OtherModelInline]
So...
When I create the Inline it required foreign key on OtherModel..
How can I show this without change the relationship?
This is the right way to do it.
If you want to use inlines, you need to specify that these two models are somewhat related.
I have an using the Django admin interface to manage a lot of objects, and one of the page is giving me issue, this page has a field to a related object (Foreign Key) that has a __str__ that also goes to its related objects, this make a lot of queries and is barely useable (Around 3000 queries to show the page as there are a LOT of objects).
I would like to know if there is a way to set a custom queryset ? I would like to add a select_related or prefetch_related to this element.
The part causing issue is this certificate requests list :
The page model (Certificate has the following attribute:
class Certificate(models.Model):
certificate_request = models.OneToOneField(
"CertificateRequest",
verbose_name=_("Certificate request"),
related_name="certificate",
blank=True,
null=True
)
And the related model has this :
class CertificateRequest(models.Model):
domain = models.ForeignKey(
"Domain",
verbose_name=_("Domain"),
related_name="certificate_requests"
)
def __str__(self):
return "{state} certificate request for {domain} from {creation_date}".format(
state=dict(self.STATUS).get(self.status),
domain=self.domain.fqdn,
creation_date=self.creation_date
)
What would be the way to fix this ? How can I set a queryset on this part ?
EDIT: I added more informations.
I tried using a custom form, but this didn't do any change :
class CertificateForm(forms.ModelForm):
certificate_request = forms.ModelChoiceField(queryset=CertificateRequest.objects.select_related("domain"))
class Meta:
model = Certificate
fields = "__all__"
#admin.register(Certificate)
class CertificateAdmin(CompareVersionAdmin):
model = Certificate
class Meta:
form = CertificateForm
You can create a custom ModelForm for your admin where you specify a ModelChoiceField for the ForeignKey. Here you can specify the queryset parameter:
# forms.py
class MyForm(forms.ModelForm):
certificate_request = forms.ModelChoiceField(queryset=CertReq.objects.foo().bar())
# select/prefetch-------^^^^^^^^^^^
class Meta:
model = Foo
# admin.py
class YourAdmin(ModelAdmin):
form = MyForm
The get_object method on the ModelAdmin class is what is responsible for retrieving the object to edit. You could certainly extend that method in your subclass to use select_related as necessary.
Due to my app requeriments I need an hierachy of users classes like:
class CommonUser(models.Model):
user = models.OneToOneField(User,on_delete=models.CASCADE)
photo = models.ImageField(upload_to="profileImages",blank=True,null=True)
#HERE: Common properties for every user
class Meta:
abstract = True
class Installer(CommonUser):
#HERE: Specific properties for Installer Companies
class Administration(CommonUser):
#HERE: Specific properties for Administration
class Client(CommonUser):
#HERE: Specific properties for Clients
Well, in view.py I need to get the profile image for an user. I get the user by the request, so I have an models.User objects and I dont know to witch class it belong. Im not able to do:
request.user.commonuser.photo
because user object doesnt have any OnetoOne relation with commonuser but with installer/administration/client...
Any idea? Thanks!
I'm on mobile, so I can't test this, but...
I would set a "related_name" on your CommonUser.user field called "commonuser". Then you can just use:
request.user.commonuser.photo
like you are already.
I think the issue is that you are referencing a Django User object to reference a backwards relationship without the proper name.
First off, I think this model is more of a Profile than User. If you don't mind using 1.9 (and postgres) then this is a perfect usecase for a JSON field. You can filter with regular lookups and don't need to specify each type. That way you can also extend the user model in such a way that a user can fulfill many roles at once. The other thing I thought of was linking it the other way around:
class UserProfile(models.Model):
user = models.OneToOneField(User,on_delete=models.CASCADE)
# ...
class Installer(models.Model):
profile = models.ForeignKey(UserProfile, related_name='installer')
#HERE: Specific properties for Installer Companies
class Administration(models.Model):
profile = models.ForeignKey(UserProfile, related_name='admin')
#HERE: Specific properties for Administration
class Client(models.Model):
profile = models.ForeignKey(UserProfile, related_name='client')
#HERE: Specific properties for Clients
I want to add few fields to every model in my django application. This time it's created_at, updated_at and notes. Duplicating code for every of 20+ models seems dumb. So, I decided to use abstract base class which would add these fields. The problem is that fields inherited from abstract base class come first in the field list in admin. Declaring field order for every ModelAdmin class is not an option, it's even more duplicate code than with manual field declaration.
In my final solution, I modified model constructor to reorder fields in _meta before creating new instance:
class MyModel(models.Model):
# Service fields
notes = my_fields.NotesField()
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
class Meta:
abstract = True
last_fields = ("notes", "created_at", "updated_at")
def __init__(self, *args, **kwargs):
new_order = [f.name for f in self._meta.fields]
for field in self.last_fields:
new_order.remove(field)
new_order.append(field)
self._meta._field_name_cache.sort(key=lambda x: new_order.index(x.name))
super(MyModel, self).__init__(*args, **kwargs)
class ModelA(MyModel):
field1 = models.CharField()
field2 = models.CharField()
#etc ...
It works as intended, but I'm wondering, is there a better way to acheive my goal?
I was having the very same problem, but I found these solutions to be problematic, so here's what I did:
class BaseAdmin(admin.ModelAdmin):
def get_fieldsets(self, request, obj = None):
res = super(BaseAdmin, self).get_fieldsets(request, obj)
# I only need to move one field; change the following
# line to account for more.
res[0][1]['fields'].append(res[0][1]['fields'].pop(0))
return res
Changing the fieldset in the admin makes more sense to me, than changing the fields in the model.
If you mainly need the ordering for Django's admin you could also create your "generic"-admin class via sub-classing Django's admin class. See http://docs.djangoproject.com/en/dev/intro/tutorial02/#customize-the-admin-form for customizing the display of fields in the admin.
You could overwrite the admin's __init__ to setup fields/fieldsets on creation of the admin instance as you wish. E.g. you could do something like:
class MyAdmin(admin.ModelAdmin):
def __init__(self, model, admin_site):
general_fields = ['notes', 'created_at', 'updated_at']
fields = [f.name for f in self.model._meta.fields if f.name not in general_fields]
self.fields = fields + general_fields
super(admin.ModelAdmin, self).__init__(model, admin_site)
Besides that i think it's not a good practice to modify the (private) _field_name_cache!
I ALSO didn't like the other solutions, so I instead just modified the migrations files directly.
Whenever you create a new table in models.py, you will have to run "python manage.py makemigrations" (I believe this in Django >= v1.7.5). Once you do this, open up the newly created migrations file in your_app_path/migrations/ directory and simply move the rows to the order you want them to be in. Then run "python manage.py migrate". Voila! By going into "python manage.py dbshell" you can see that the order of the columns is exactly how you wanted them!
Downside to this method: You have to do this manually for each table you create, but fortunately the overhead is minimal. And this can only be done when you're creating a new table, not to modify an existing one.