Django: Accessing parent object in new linline object - django

I have been combing through the internet for quite some while without finding any solution to this problem.
What I am trying to do...
I have the following models:
class TrackingEventType(models.Model):
required_previous_event = models.ForeignKey(TrackingEventType)
class TrackingEvent(models.Model):
tracking = models.ForeignKey(Tracking)
class Tracking(models.Model):
last_event = models.ForeignKey(TrackingEvent)
Now the main model is Tracking, so my admin for Tracking looks like this:
class TrackingEventInline(admin.TabularInline):
model = TrackingEvent
extra = 0
class TrackingAdmin(admin.ModelAdmin):
inlines = [TrackingEventInline]
That's it for the current setup.
Now my quest:
In the TrackingAdmin, when I add new TrackingEvent inlines, I want to limit the options of TrackingEventType to onlye those, that are allowed to follow on the last TrackingEvent of the Tracking. (Tracking.last_event == TrackingEventType.required_previous_event).
For this, I would need to be able to access the related Tracking on the InlineTrackingEvent, to access the last_event and filter the options for TrackingEventType accordingly.
So I found this: Accessing parent model instance from modelform of admin inline, but when I set up TrackingEventInline accordingly:
class MyFormSet(forms.BaseInlineFormSet):
def _construct_form(self, i, **kwargs):
kwargs['parent_object'] = self.instance
print self.instance
return super(MyFormSet, self)._construct_form(i, **kwargs)
class MyForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
print kwargs
self.parent_object = kwargs.pop('parent_object')
super(MyForm, self).__init__(*args, **kwargs)
class TrackingEventInline(admin.TabularInline):
form = MyForm
formset = MyFormSet
model = TrackingEvent
extra = 0
I get a KeyError at /admin/.../tracking/2/change/ 'parent_object' from self.parent_object = kwargs.pop('parent_object')
Does anyone know how to solve this? Am I approaching the problem the wrong way? I guess this would be pretty easy in a custom form in the frontend, but I really want to use the admin, because the whole application is built to be used from the admin, and it would be a hell lot of work to build a custom admin interface just because of this problem :)

Ok, so posting on StackOverflow is always helping to get the problem straight. I was able to put together a solution that works for me.
It includes defining my own Form in a outer function, as well as defining two InlineAdmin objects for TrackingEvent (one for update / edit, one just for insert).
Here's the code:
def create_trackingevent_form(tracking):
"""
"""
class TrackingEventForm(forms.ModelForm):
"""
Form for Tracking Event Inline
"""
def clean(self):
"""
May not be needed anymore, since event type choices are limited when creating new event.
"""
next_eventtype = self.cleaned_data['event_type']
tracking = self.cleaned_data['tracking']
# get last event, this also ensures last_event gets updated everytime the change form for TrackingEvent is loaded
last_eventtype = tracking.set_last_event()
if last_eventtype:
last_eventtype = last_eventtype.event_type
pk = self.instance.pk
insert = pk == None
# check if the event is updated or newly created
if insert:
if next_eventtype.required_previous_event == last_eventtype:
pass
else:
raise forms.ValidationError('"{}" requires "{}" as last event, "{}" found. Possible next events: {}'.format(
next_eventtype,
next_eventtype.required_previous_event,
last_eventtype,
'"%s" ' % ', '.join(map(str, [x.name for x in tracking.next_tracking_eventtype_options()]))
)
)
else:
pass
return self.cleaned_data
def __init__(self, *args, **kwargs):
# You can use the outer function's 'tracking' here
self.parent_object = tracking
super(TrackingEventForm, self).__init__(*args, **kwargs)
self.fields['event_type'].queryset = tracking.next_tracking_eventtype_options()
#self.fields['event_type'].limit_choices_to = tracking.next_tracking_eventtype_options()
return TrackingEventForm
class TrackingEventInline(admin.TabularInline):
#form = MyForm
#formset = MyFormSet
model = TrackingEvent
extra = 0
#readonly_fields = ['datetime', 'event_type', 'note']
def has_add_permission(self, request):
return False
class AddTrackingEventInline(admin.TabularInline):
model = TrackingEvent
extra = 0
def has_change_permission(self, request, obj=None):
return False
def queryset(self, request):
return super(AddTrackingEventInline, self).queryset(request).none()
def get_formset(self, request, obj=None, **kwargs):
if obj:
self.form = create_trackingevent_form(obj)
return super(AddTrackingEventInline, self).get_formset(request, obj, **kwargs)
I hope this helps other people with the same problem.. Some credit to the Stack Overflow threads that helped me come up with this:
Prepopulating inlines based on the parent model in the Django Admin
Limit foreign key choices in select in an inline form in admin
https://docs.djangoproject.com/en/1.9/ref/models/instances/#django.db.models.Model.clean_fields
Please do not hesitate to ask questions if you have any

Related

How can I filter the queryset I use in my ModelChoiceField field?

I have looked at several answers on SO but I haven't found one that address my particular case.
I have this ModelForm which I am using in Django admin panel.
class AssignInventoryForm(ModelForm):
class Meta:
model = Driver
fields = []
template = forms.ModelChoiceField(queryset=ItemTemplate.objects.all(),
empty_label="(Select Template)")
template.label = 'Template'
def save(self, driver):
driver = self.form_action(driver)
return driver
I would like to be able to filter ItemTemplate like so:
ItemTemplate.objects.filter(id=driver.item.id)
But obviously driver is not defined at that point of the code.
I found a good answer from here: https://simpleisbetterthancomplex.com/questions/2017/03/22/how-to-dynamically-filter-modelchoices-queryset-in-a-modelform.html
Here's what I had to change in my code.
In my admin class, DriverAdmin my proccess_action method now starts out like this:
def process_action(self, request, driver_uid, action_form, action_title):
driver = self.get_object(request, driver_uid)
if request.method != 'POST':
# Added drive as parameter to action_form.
form = action_form(driver)
else:
# Added drive as parameter to action_form BEFORE request.POST
form = action_form(driver, request.POST)
... rest of method unchanged ...
In my AssignInventoryForm() class I added this __init__() method.
def __init__(self, driver, *args, **kwargs):
super(AssignInventoryForm, self).__init__(*args, **kwargs)
self.fields['template'].queryset = ItemTemplate.objects.filter(id=driver.item.id)

Django combine two fields data into a queryset

I have a model say Club where we have fields like:
manager = models.ForeignKey(Users, related_name="return_manager", on_delete=models.CASCADE)
members = models.ManyToManyField(Users, related_name="return_members", blank=True)
Now I want to create a drop down in a form where I can add both the manager and members to it. I tried making two requests for Club.objects.filter(pk=mypk).members.all() and Club.objects.filter(pk=mypk).manager. I tried chain function and using '| ' operator but none worked. I think the manager is a single User and not a queryset, that is what the main problem is. Any workarounds?
One possible way getting all of the information together involves modifying your form choices.
In your view you would need to pass the choices along as context to your form.
def my_view(request, club_pk):
context = {}
context.update({
"manager": Club.objects.get(pk=club_pk).manager,
"members": Club.objects.get(pk=club_pk).members.all()
}
form = MyForm(request.POST or None, request=request, context=context)
In your form, you would need to modify the __init__ method to update your choices like so:
class MyForm(forms.Form):
all_club_members = forms.ChoiceField('Manager + Members', required=True)
def __init__(self, *args, **kwargs):
self.context = kwargs.pop('context', None)
super(MyForm, self).__init__(*args, **kwargs)
manager_tuple = [(self.context['manager'].id, self.context['manager'].display_name)]
members_tuples = [(member.id, member.display_name) for member in self.context['members']
self.fields['all_club_members'].choices = manager_tuple + members_tuples
Try this:
manager = [Club.objects.filter(pk=mypk).manager]
members = Club.objects.filter(pk=mypk).members.all()
userlist = list(manager) + list(members)
return Users.objects.filter(pk__in=userlist)
Should create a queryset of all users

ModelChoiceField in forms.Form won't validate if queryset is overridden

I have a django ModelChoiceField that won't validate if I override the queryset.
class PersonalNote(forms.Form):
tile = ModelChoiceField(queryset=Tile.objects.none())
note = forms.CharField()
form = PersonalNote()
form.fields['tile'].queryset = Tile.objects.filter(section__xxx=yyy)
The form.is_valid() error is: "Select a valid choice. That choice is not one of the available choices".
If Tile.objects.none() is replaced with Tile.objects.all() it validates, but loads far too much data from the database. I've also tried:
class PersonalNote(forms.Form):
tile = ModelChoiceField(queryset=Tile.objects.none())
note = forms.CharField()
def __init__(self, *args, **kwargs):
yyy = kwargs.pop('yyy', None)
super(PersonalNote, self).__init__(*args, **kwargs)
if yyy:
self.fields['tile'].queryset = Tile.objects.filter(section__xxx=yyy)
What might be wrong here? Note the real application also overrides the label, but that does not seem to be a factor here:
class ModelChoiceField2(forms.ModelChoiceField):
def label_from_instance(self, obj):
assert isinstance(obj,Tile)
return obj.child_title()
After 2 hours I found the solution. Because you specified a queryset of none in the class definition, when you instantiate that PersonalNote(request.POST) to be validated it is referenceing a null query set
class PersonalNote(forms.Form):
tile = ModelChoiceField(queryset=Tile.objects.none())
note = forms.CharField()
To fix this, when you create your form based on a POST request be sure to overwrite your queryset AGAIN before you check is_valid()
def some_view_def(request):
form = PersonalNote(request.POST)
**form.fields['tile'].queryset = Tile.objects.filter(section__xxx=yyy)**
if form.is_valid():
#Do whatever it is
When you pass an empty queryset to ModelChoiceField you're saying that nothing will be valid for that field. Perhaps you could filter the queryset so there aren't too many options.
I also had this problem. The idea is to dynamically change the queryset of a ModelChoiceField based on a condition (in my case it was a filter made by another ModelChoiceField).
So, having the next model as example:
class FilterModel(models.Model):
name = models.CharField()
class FooModel(models.Model):
filter_field = models.ForeignKey(FilterModel)
name = models.CharField()
class MyModel(models.Model):
foo_field = models.ForeignKey(FooModel)
As you can see, MyModel has a foreign key with FooModel, but not with FilterModel. So, in order to filter the FooModel options, I added a new ModelChoiceField on my form:
class MyForm(forms.ModelForm):
class Meta:
model = MyModel
def __init__(self, *args, **kwargs):
# your code here
self.fields['my_filter_field'] = forms.ModelChoiceField(FilterModel, initial=my_filter_field_selected)
self.fields['my_filter_field'].queryset = FilterModel.objects.all()
Then, on your Front-End you can use Ajax to load the options of foo_field, based on the selected value of my_filter_field. At this point everyting should be working. But, when the form is loaded, it will bring all the posible options from FooModel. To avoid this, you need to dynamically change the queryset of foo_field.
On my form view, I passed a new argument to MyForm:
id_filter_field = request.POST.get('my_filter_field', None)
form = MyForm(data=request.POST, id_filter_field=id_filter_field)
Now, you can use that argument on MyForm to change the queryset:
class MyForm(forms.ModelForm):
# your code here
def __init__(self, *args, **kwargs):
self.id_filter_field = kwargs.pop('id_filter_field', None)
# your code here
if self.id_filter_field:
self.fields['foo_field'].queryset = FooModel.objects.filter(filter_field_id=self.id_filter_field)
else:
self.fields['foo_field'].queryset = FooModel.objects.none()

django admin - access request.user in BaseInlineFormSet

I've just created a forms.models.BaseInlineFormSet to override the default formset for a TabularInline model. I need to evaluate the user's group in formset validation (clean) because some groups must write a number inside a range (0,20).
I'm using django admin to autogenerate the interface.
I've tried getting the request and the user from the kwargs in the init method, but I couldn't get the reference.
This is what I have now:
class OrderInlineFormset(forms.models.BaseInlineFormSet):
def __init__(self, *args, **kwargs):
self.user = kwargs.pop('user')
super(OrderInlineFormset, self).__init__(*args, **kwargs)
def clean(self):
# get forms that actually have valid data
count = 0
for form in self.forms:
try:
if form.cleaned_data:
count += 1
if self.user.groups.filter(name='Seller').count() == 1:
if form.cleaned_data['discount'] > 20:
raise forms.ValidationError('Not authorized to specify a discount greater than 20%')
except AttributeError:
# annoyingly, if a subform is invalid Django explicity raises
# an AttributeError for cleaned_data
pass
if count < 1:
raise forms.ValidationError('You need to specify at least one item')
class OrderItemInline(admin.TabularInline):
model = OrderItem
formset = OrderInlineFormset
Then I use it as inlines = [OrderItemInline,] in my ModelAdmin.
Unfortunatly self.user is always None so I cannot compare the user group and the filter is not applied. I need to filter it because other groups should be able to specify any discount percent.
How can I do? If you also need the ModelAdmin code I'll publish it (I just avoided to copy the whole code to avoid confusions).
Well, I recognise my code there in your question, so I guess I'd better try and answer it. But I would say first of all that that snippet is really only for validating a minimum number of forms within the formset. Your use case is different - you want to check something within each form. That should be done with validation at the level of the form, not the formset.
That said, the trouble is not actually with the code you've posted, but with the fact that that's only part of it. Obviously, if you want to get the user from the kwargs when the form or formset is initialized, you need to ensure that the user is actually passed into that initialization - which it isn't, by default.
Unfortunately, Django's admin doesn't really give you a proper hook to intercept the initialization itself. But you can cheat by overriding the get_form function and using functools.partial to wrap the form class with the request argument (this code is reasonably untested, but should work):
from functools import partial
class OrderForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
self.user = kwargs.pop('user')
super(OrderForm, self).__init__(*args, **kwargs)
def clean(self)
if self.user.groups.filter(name='Seller').count() == 1:
if self.cleaned_data['discount'] > 20:
raise forms.ValidationError('Not authorized to specify a discount greater than 20%')
return self.cleaned_data
class MyAdmin(admin.ModelAdmin):
form = OrderForm
def get_form(self, request, obj=None, **kwargs):
form_class = super(MyAdmin, self).get_form(request, obj, **kwargs)
return functools.partial(form_class, user=request.user)
Here's another option without using partials. First override the get_formset method in your TabularInline class.
Assign request.user or what ever extra varaibles you need to be available in the formset as in example below:
class OrderItemInline(admin.TabularInline):
model = OrderItem
formset = OrderInlineFormset
def get_formset(self, request, obj=None, **kwargs):
formset = super(OrderProductsInline, self).get_formset(request, obj, **kwargs)
formset.user = request.user
return formset
Now the user is available in the formset as self.user
class OrderInlineFormset(forms.models.BaseInlineFormSet):
def clean(self):
print(self.user) # is available here

Django AdminForm field default value

I have a Django admin form.
And now I want to fill it's initial field with data based on my model. So I tried this:
class OrderForm(forms.ModelForm):
class Meta:
model = Order
email = CharField(initial="null", widget=Textarea(attrs={'rows': 30, 'cols': 100}))
def __init__(self, *args, **kwargs):
self.request = kwargs.pop('request', None)
products = kwargs['instance'].products.all()
self.message = purchase_message % (
"".join(["<li>" + p.name + ": " + str(p.price) + "</li>" for p in products]),
reduce(lambda x, y:x + y.price, products, 0)
)
# and here I have a message in self.message variable
super(OrderForm, self).__init__(*args, **kwargs)
At this point i don't know how to access email field to set it's initial value before widget is rendered. How can i do this?
Assuming the value is based on 'request' you should use this:
class MyModelAdmin(admin.ModelAdmin):
def get_form(self, request, obj=None, **kwargs):
form = super(MyModelAdmin, self).get_form(request, obj, **kwargs)
form.base_fields['my_field_name'].initial = 'abcd'
return form
Since Django 1.7 there is a function get_changeform_initial_data in ModelAdmin that sets initial form values:
def get_changeform_initial_data(self, request):
return {'name': 'custom_initial_value'}
EDIT: Apart from that, #Paul Kenjora's answer applies anyway, which might be useful if you already override get_form.
In case of inline (InlineModelAdmin) there is no get_changeform_initial_data. You can override get_formset and set formset.form.base_fields['my_field_name'].initial.
I'm not too sure what you need to set email to, but You can set the initial values in lots of different places.
Your function def init() isn't indented correctly which i guess is a typo? Also, why are you specifically giving the email form field a TextInput? It already renders this widget by default
You can set the email's initial value in your form's initialized (def __ init __(self))
(self.fields['email'].widget).initial_value = "something"
or in the model.py
email = models.CharField(default="something")
or as you have in forms.py
email = models.CharField(initial="something")
I needed the first solution of pastylegs since the other ones overwrite the whole Widget including, for example, the help text. However, it didn't work for me as he posted it. Instead, I had to do this:
self.fields['email'].initial = 'something'
In my case, I was trying to do a personalized auto-increment(based on current data and not a simple default) in a field of a django admin form.
This code is worked for me (Django 1.11):
from django import forms
class MyAdminForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.initial['field_name'] = 'initial_value'