I have a class in models.py:
class Person(AbstractUser):
def __unicode__(self):
return u'%s %s' % (self.first_name, self.last_name)
It`s related to AbstractUser from contrib/models.py
I`ve made a class that lets make additional fields to it.
class ExtraTextField(models.Model):
add = models.ForeignKey(Person)
new_field_text = models.TextField(max_length=200, verbose_name='content')
def __unicode__(self):
return u'%s' % (self.new_field_text)
class AddText(admin.StackedInline):
model = ExtraTextField
extra = 0
class AdminForm(admin.ModelAdmin):
inlines = [AddText]
As you see, amount of fields is not defined, so I can`t just put them into class Person. But as a logical continuing, these additional fields are not saved in the database. Please, help, how can I solve this problem?
Related
I have a django.db.models.Model A whose instances are created in a rest_framework.serializers.ModelSerializer from POST requests.
Depending on the data being sent in the POST, I would like to create one of several other "addon" models, let's say B or C, which I link to the original through a django.db.models.OneToOneField:
from django.db import models
class A(models.Model):
some_field = models.CharField()
class B(models.Model):
a = models.OneToOneField(A, related_name='addon', on_delete=models.CASCADE)
class C(models.Model):
a = models.OneToOneField(A, related_name='addon', on_delete=models.CASCADE)
What I would like to is to have a serializer which validates the incoming data, including some string indicating which addon to use. The serializer then creates the model instance of A and based on this creates the addon model.
I do not want to create a utility field in model A used to determine which addon to use, I would like to create the model directly using the instance of model A and information from the POST itself.
At the same time when accessing the data through a get, I would like to return the original string used to determine which addon to use.
What I have come up with so far:
from rest_framework import serializers
str2model = {'b': B, 'c': C}
class AddonField(serializers.Field):
def to_representation(self, value):
# I completely ignore "value" as no "internal value" is set in "to_internal_value"
myvalue = self.parent.instance.addon
for addon_name, addon_class in str2model.items():
if isinstance(myvalue, addon_class):
return addon_name
def to_internal_value(self, data):
# I create the "internal value" after "A" instance is created, thus here I do nothing?
return data
class ASerializer(serializers.ModelSerializer):
some_field = serializers.CharField()
the_addon = AddonField()
def validate_the_addon(self, value): # here addon is a string
if value in str2model.keys():
return value
def create(self, validated_data):
addon_name = validated_data.pop('the_addon')
addon_class = str2model[addon]
a = super(ASerializer, self).create(validated_data)
addon_class.objects.create(a=a)
return a
class Meta:
model = A
fields = ["some_field", "the_addon"]
When testing this I get:
AttributeError: Got AttributeError when attempting to get a value for field `the_addon` on serializer `ASerializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `A` instance.
Original exception text was: 'A' object has no attribute 'the_addon'.
How can I temporarily store the_addon in the serializer until the A instance has been created?
This is how I would typically approach it
# Serializer
class ASerializer(serializers.Serializer):
some_field = serializers.CharField()
addon_b = serializers.CharField(required=False, allow_null=True)
addon_c = serializers.CharField(required=False, allow_null=True)
def create(self, validated_data):
addon_b = validated_data.pop('addon_b')
addon_c = validated_data.pop('addon_c')
a = A.objects.create(some_field=validated_data['some_field'])
if addon_b:
B.objects.create(a=a)
if addon_c:
C.objects.create(a=a)
return a
You can do other validations if necessary.
class TestAPIView01(generics.CreateAPIView):
permission_classes = {}
serializer_class = serializers.ASerializer
queryset = A.objects.all()
Also, look at the related_name on B and C you may want to consider making them different, as that might throw an error in the future. Cheers
I'm experimenting with django-nonrel on appengine and trying to use a djangotoolbox.fields.ListField to implement a many-to-many relation. As I read in the documentation a ListField is something that you can use to make a workaround for djamgo-nonrel not supporting many-to-many relations.
This is an excerpt from my model:
class MyClass(models.Model):
field = ListField(models.ForeignKey(AnotherClass))
So if I am getting this right I am creating a list of foreign keys to another class to show a relationship with multiple instances of another class
With this approach everything works fine ... No Exceptions. I can create `MyClass' objects in code and views. But when I try to use the admin interface I get the following error
No form field implemented for <class 'djangotoolbox.fields.ListField'>
So I though I would try something that I haven't done before. Create my own field. Well actually my own form for editing MyClass instances in the admin interface. Here is what I did:
class MyClassForm(ModelForm):
field = fields.MultipleChoiceField(choices=AnotherClass.objects.all(), widget=FilteredSelectMultiple("verbose_name", is_stacked=False))
class Meta:
model = MyClass
then I pass MyClassForm as the form to use to the admin interface
class MyClassAdmin(admin.ModelAdmin):
form = MyClassForm
admin.site.register(MyClass, MyClassAdmin)
I though that this would work but It doesn't. When I go to the admin interface I get the same error as before. Can anyone tell what I am doing wrong here ... or if you have any other suggestions or success stories of using the ListField, SetField, etc. from djangotoolbox.fields in the admin interface it would be very much appreciated.
OK, here is what I did to get this all working ...
I'll start from the beginning
This is what what my model looked like
class MyClass(models.Model):
field = ListField(models.ForeignKey(AnotherClass))
I wanted to be able to use the admin interface to create/edit instances of this model using a multiple select widget for the list field. Therefore, I created some custom classes as follows
class ModelListField(ListField):
def formfield(self, **kwargs):
return FormListField(**kwargs)
class ListFieldWidget(SelectMultiple):
pass
class FormListField(MultipleChoiceField):
"""
This is a custom form field that can display a ModelListField as a Multiple Select GUI element.
"""
widget = ListFieldWidget
def clean(self, value):
#TODO: clean your data in whatever way is correct in your case and return cleaned data instead of just the value
return value
These classes allow the listfield to be used in the admin. Then I created a form to use in the admin site
class MyClassForm(ModelForm):
def __init__(self, *args, **kwargs):
super(MyClasstForm,self).__init__(*args, **kwargs)
self.fields['field'].widget.choices = [(i.pk, i) for i in AnotherClass.objects.all()]
if self.instance.pk:
self.fields['field'].initial = self.instance.field
class Meta:
model = MyClass
After having done this I created a admin model and registered it with the admin site
class MyClassAdmin(admin.ModelAdmin):
form = MyClassForm
def __init__(self, model, admin_site):
super(MyClassAdmin,self).__init__(model, admin_site)
admin.site.register(MyClass, MyClassAdmin)
This is now working in my code. Keep in mind that this approach might not at all be well suited for google_appengine as I am not very adept at how it works and it might create inefficient queries an such.
As far as I understand, you're trying to have a M2M relationship in django-nonrel, which is not an out-of-the-box functionality. For starters, if you want a quick hack, you can go with this simple class and use a CharField to enter foreign keys manually:
class ListFormField(forms.Field):
""" A form field for being able to display a djangotoolbox.fields.ListField. """
widget = ListWidget
def clean(self, value):
return [v.strip() for v in value.split(',') if len(v.strip()) > 0]
But if you want to have a multiple selection from a list of models normally you'd have to use ModelMultipleChoiceField, which is also not functional in django-nonrel. Here's what I've done to emulate a M2M relationship using a MultipleSelectField:
Let's say you have a M2M relationship between 2 classes, SomeClass and AnotherClass respectively. You want to select the relationship on the form for SomeClass. Also I assume you want to hold the references as a ListField in SomeClass. (Naturally you want to create M2M relationships as they're explained here, to prevent exploding indexes if you're working on App Engine).
So you have your models like:
class SomeClass(models.Model):
another_class_ids = ListField(models.PositiveIntegerField(), null=True, blank=True)
#fields go here
class AnotherClass(models.Model):
#fields go here
And in your form:
class SomeClassForm(forms.ModelForm):
#Empty field, will be populated after form is initialized
#Otherwise selection list is not refreshed after new entities are created.
another_class = forms.MultipleChoiceField(required=False)
def __init__(self, *args, **kwargs):
super(SomeClassForm,self).__init__(*args, **kwargs)
self.fields['another_class'].choices = [(item.pk,item) for item in AnotherClass.objects.all()]
if self.instance.pk: #If class is saved, highlight the instances that are related
self.fields['another_class'].initial = self.instance.another_class_ids
def save(self, *args, **kwargs):
self.instance.another_class_ids = self.cleaned_data['another_class']
return super(SomeClassForm, self).save()
class Meta:
model = SomeClass
Hopefully this should get you going for the start, I implemented this functionality for normal forms, adjust it for admin panel shouldn't be that hard.
This could be unrelated but for the admin interface, be sure you have djangotoolbox listed after django.contrib.admin in the settings.. INSTALLED_APPS
You could avoid a custom form class for such usage by inquiring for the model object
class ModelListField(ListField):
def __init__(self, embedded_model=None, *args, **kwargs):
super(ModelListField, self).__init__(*args, **kwargs)
self._model = embedded_model.embedded_model
def formfield(self, **kwargs):
return FormListField(model=self._model, **kwargs)
class ListFieldWidget(SelectMultiple):
pass
class FormListField(MultipleChoiceField):
widget = ListFieldWidget
def __init__(self, model=None, *args, **kwargs):
self._model = model
super(FormListField, self).__init__(*args, **kwargs)
self.widget.choices = [(unicode(i.pk), i) for i in self._model.objects.all()]
def to_python(self, value):
return [self._model.objects.get(pk=key) for key in value]
def clean(self, value):
return value
Currently, Django 1.2.3 User model unicode is
def __unicode__(self):
return self.username
and I'd like to override it so its:
def __unicode__(self):
return u'%s, %s' % (self.last_name, self.first_name)
How to?
To similar effect:
User._meta.ordering = ['last_name', 'first_name']
works when defined anywhere
If you simply want to show the full name in the admin interface (which is what I needed), you can easily monkey-patch it during runtime. Just do something like this in your admin.py:
from django.contrib import admin
from django.contrib.auth.models import User
def user_unicode(self):
return u'%s, %s' % (self.last_name, self.first_name)
User.__unicode__ = user_unicode
admin.site.unregister(User)
admin.site.register(User)
Django's Proxy Model solved this problem.
This is my solution:
form.fields['students'].queryset = Student.objects.filter(id__in = school.students.all())
Here school.students is a m2m(User), Student is a proxy model of User.
class Student(User):
class Meta:
proxy = True
def __unicode__(self):
return 'what ever you want to return'
All above helps you to solve if your want to show your User ForeignKey in your custom method. If your just want to change it in admin view, there is a simple solution:
def my_unicode(self):
return 'what ever you want to return'
User.__unicode__ = my_unicode
admin.site.unregister(User)
admin.site.register(User)
add these codes to admin.py, it works.
If you need to override these, chances are you would need more customizations later on.
The cleanest practice would be using a user profile models instead of touching the User model
Create a proxy User class.
class UserProxy(User):
class Meta:
proxy = True
ordering = ['last_name', 'first_name']
def __unicode__(self):
return u'%s, %s' % (self.last_name, self.first_name)
I just found this simple method on django 1.5
def __unicode__(self):
a = self.last_name
b = self.first_name
c = a+ "-" +b
return c
it will return what you want
I have the follow code example, which is a simplified abstraction of a real world project I'm working on:
from django.db import models
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic
class FeatureSet(models.Model):
"""
Feature Set
"""
name = models.CharField(max_length=255)
def __unicode__(self):
return u"%s" % self.name
class GenericObjectAlpha(models.Model):
title = models.CharField(max_length=255)
feature_sets = models.ManyToManyField(FeatureSet, through='Feature')
def __unicode__(self):
return u"%s" % self.title
class GenericObjectBeta(models.Model):
title = models.CharField(max_length=255)
feature_sets = models.ManyToManyField(FeatureSet, through='Feature')
def __unicode__(self):
return u"%s" % self.title
class Feature(models.Model):
"""
Feature
"""
# FK to feature set
feature_set = models.ForeignKey(FeatureSet)
# FK to generic object, Generic object alpha or beta... or others
content_type = models.ForeignKey(
ContentType,
default='article',
limit_choices_to={ 'model__in': ('genericobjectalpha', 'genericobjectbeta') },
related_name="play__feature_set__feature")
object_id = models.PositiveIntegerField(
"Feature object lookup")
content_object = generic.GenericForeignKey(
'content_type',
'object_id')
# Extra fields on a m2m relationship
active = models.BooleanField()
order = models.PositiveIntegerField()
def __unicode__(self):
return u"%s::%s" % (self.feature_set, self.content_object)
This line causes an error:
feature_sets = models.ManyToManyField(FeatureSet, through='Feature')
Obviously because the 'through' model lacks a corresponding FK to each side of the m2m. What I'd like to achieve here, is that one side of the m2m relationship is generic, and, that I can specify my own intermediary join table, to do the usual adding of custom fields etc.
What are my options for accomplishing this?
Note, its currently an important requirement to include the feature_sets = models.ManyToManyField(FeatureSet, through='Feature') line in the generic model, mostly for admin UI purposes. The reason why its generic is that its not yet determined how many models this line will be placed upon.
I am trying to build an example app in Google App Engine using django-nonrel. and am having problems implementing ListField attribute into a model.
I have created an app test_model and have included it as an installed app in my settings. The model.py is:
from django.db import models
from djangotoolbox import *
from dbindexer import *
# Create your models here.
class Example(models.Model):
some_choices = models.ListField('Choice_examples')
notes = models.CharField(max_length='20')
updated_at = models.DateTimeField(auto_now=True)
def __unicode__(self):
return u'%s' % (self.notes)
class Choice_examples(models.Model):
name = models.CharField(max_length='30')
def __unicode__(self):
return u'%s' % (self.name)
The above example gives me:
AttributeError:'module' object has no attribute 'Model'
If I comment out the djangotoolbox import, I get the following :
AttributeError: 'module' object has no attribute 'ListField'
What am I doing wrong here? I can't seem to find any documention as to how to go about using ListField in django-nonrel. Is that because it is supposed to really obvious?
Your imports are smashing each other:
from django.db import models
from djangotoolbox import *
The second import will replace the django.db models with djangotoolbox' empty models module. Using from X import * is a terrible idea in general in Python and produces confusing results like these.
If you're looking to use ListField from djangotoolbox, use:
from djangotoolbox import fields
and refer to the ListField class as fields.ListField.
OK, here is what I did to be able to use ListFields. MyClass the equivalent to your Example class and AnotherClass is the same as your Choice_examples. What I describe will allow you to use ListFields in the admin interface and your self implemented views.
I'll start from the beginning
This is what what my model looks like
class MyClass(models.Model):
field = ListField(models.ForeignKey(AnotherClass))
I wanted to be able to use the admin interface to create/edit instances of this model using a multiple select widget for the list field. Therefore, I created some custom classes as follows
class ModelListField(ListField):
def formfield(self, **kwargs):
return FormListField(**kwargs)
class ListFieldWidget(SelectMultiple):
pass
class FormListField(MultipleChoiceField):
"""
This is a custom form field that can display a ModelListField as a Multiple Select GUI element.
"""
widget = ListFieldWidget
def clean(self, value):
#TODO: clean your data in whatever way is correct in your case and return cleaned data instead of just the value
return value
These classes allow the listfield to be used in the admin. Then I created a form to use in the admin site
class MyClassForm(ModelForm):
def __init__(self, *args, **kwargs):
super(MyClasstForm,self).__init__(*args, **kwargs)
self.fields['field'].widget.choices = [(i.pk, i) for i in AnotherClass.objects.all()]
if self.instance.pk:
self.fields['field'].initial = self.instance.field
class Meta:
model = MyClass
After having done this I created a admin model and registered it with the admin site
class MyClassAdmin(admin.ModelAdmin):
form = MyClassForm
def __init__(self, model, admin_site):
super(MyClassAdmin,self).__init__(model, admin_site)
admin.site.register(MyClass, MyClassAdmin)
This is now working in my code. Keep in mind that this approach might not at all be well suited for google_appengine as I am not very adept at how it works and it might create inefficient queries an such.
I don't know, but try with:
class Choice_examples(models.Model):
name = models.CharField(max_length='30')
def __unicode__(self):
return u'%s' % (self.name)
class Example(models.Model):
some_choices = models.ListField(Choice_examples)
notes = models.CharField(max_length='20')
updated_at = models.DateTimeField(auto_now=True)
def __unicode__(self):
return u'%s' % (self.notes)
Looks like the answer is that you cannot pass an object into fields.ListField.
I have ditched trying to work with ListField as documentation is limited and my coding skills aren't at a level for me to work it out.
Anyone else coming across a similar problem, you should consider create a new model to map the ManyToMany relationships. And if the admin view is important, you should look into the following to display the ManyToMany table inline with any given admin view:
http://docs.djangoproject.com/en/1.2/ref/contrib/admin/#s-working-with-many-to-many-models