Looking for info how django formsets validation works, though it is more complicated than it sounds. I have a formset with values, part of these values can be inserted there by javascript (it means they do not exist in database yet).
class RequireOneFormSet(BaseInlineFormSet):
def clean(self):
if any(self.errors):
return
form_count = len([f for f in self.forms if f.cleaned_data])
if form_count < 1:
raise ValidationError(_('At least one %(object)s is required.') %
{'object':
_(self.model._meta.object_name.lower())})
class VariantInline(admin.StackedInline):
model = Variant
extra = 1
formset = RequireOneFormSet
class ProductAdmin(admin.ModelAdmin):
class Meta:
model = Product
class Media:
js = (os.path.join(STATIC_URL, 'js', 'admin_utils.js'), )
exclude = ('slug',)
filter_horizontal = ('category',)
inlines = [ImageInline, DetailInline, VariantInline]
manufacturer = ModelChoiceField(Manufacturer.objects.all())
list_filter = ('name', 'manufacturer', 'category')
list_display = ('name', 'manufacturer')
search_fields = ('name',)
save_as = True
Next, basing on those entries I`d like to create objects during formset validation. Django complains that there is no such object in DB when 'Save' button is clicked.
I have tried to override clean method of model, clean of ModelAdmin, save_formset of formset but with no luck as these values created by javascript are filtered out earlier in process. I am looking for info which method takes care of that, and can it be overriden?
EDIT:
Added some code, used view is a generic one from Django.
I`ve managed to resolve it. Key was to create my own field and override clean() method there. As you can see in file django/forms/models.py in class ModelMultipleChoiceField clean() is responsible for checking send values.
class DetailsField(ModelMultipleChoiceField):
def clean(self, value):
(code here)
class VariantForm(ModelForm):
details = DetailsField(queryset=Detail.objects.all(),
widget=FilteredSelectMultiple('details', False))
class VariantInline(admin.StackedInline):
model = Variant
extra = 1
formset = RequireOneFormSet
form = VariantForm
Related
I want to overwrite the __str__ method in Django admin when using the autocomplete_fields = () but the returned values are using __str__.
I have a form something like
class MyAdminForm(forms.ModelForm):
placement = forms.Select(
choices = Organisation.objects.active(),
)
class Meta:
model = Lead
fields = '__all__'
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['placement'].label_from_instance = lambda obj: f'{str(obj)} {obj.post_code}'
This will provide back a Select with the organisation name and post code in the dropdown fields. But there are some 80k choices so I need to using autocomplete. Within within admin.py I have
class LeadAdmin(admin.ModelAdmin):
form = LeadAdminForm
autocomplete_fields = ('placement',)
As soon as I add the autocomplete_fields I lose my postcode and it reverts to just showing the __str__
Hoa can I used autocomplete_fields and overwrite the __str__ method?
This question is answered through Benbb96 comment above which I've copied here so I can close it
So maybe this answer can help you :
stackoverflow.com/a/56865950/8439435 – Benbb96
So to make the above possible I have found out that I have to have ManytoMany Field that is not a problem.
That field is in the form as follows:
class Form(forms.ModelForm):
class Meta:
model = MyModel
fields = ['notes', 'scan']
widgets = {
'scan': forms.CheckboxSelectMultiple(),
}
In the view I have this then:
form = Form(request.POST)
if from.is_valid():
inst = from.save(commit=False)
inst.something = something
inst.save()
Now what do I do, to save the test or scan from the form?
I tried :
inst.test.add(form.cleaned_data['test'])
But that doesn't work for test or scan.
The Model looks like this:
class MyModel(models.Model):
id = models.AutoField(primary_key=True)
notes = models.TextField(default='')
scan = models.ManyToManyField(Scan)
....
Please help I wasn't able find anything in the Internet about this
Thanks!
The documentation of the Form's save method tells it all: If you have a ModelForm that contains the model's ManyToManyField like this:
class MyForm(forms.ModelForm):
class Meta:
model = MyModel
fields = ['__all__'] # or fields = ['scans'] assuming scans is the M2M field in MyModel
Then you have two ways to save the relationships:
Directly, using form.save()
Calling save_m2m() is only required if you use save(commit=False). When you use a simple save() on a form, all data – including many-to-many data – is saved without the need for any additional method calls.
Or indirectly because you want to manipulate the instance before saving:
if form.is_valid():
instance = form.save(commit=False)
instance.some_field = some_value
instance.save()
form.save_m2m() # this saves the relationships
I have a pretty basic definition within my forms.py to pull data from my submitted form. Something I have done with other apps, but for some reason, it is not working at the moment. I feel like I'm overlooking something. Whenever I print(image_height) I get None.
models.py
height_field = models.IntegerField(default=1200)
forms.py
class PostForm(ModelForm):
class Meta:
model = Post
fields = ['user', 'title', 'content', 'post_image',
'height_field', 'width_field', 'draft', 'publish']
def clean_post_image(self):
post_image = self.cleaned_data["post_image"]
image_height = self.cleaned_data.get("height_field")
print(image_height)
return post_image
If you want to validate your form field with respect to other field, you should do that in your clean method.
From the docs,
The form subclass’s clean() method can perform validation that requires access to multiple form fields. This is where you might put in checks such as “if field A is supplied, field B must contain a valid email address”. This method can return a completely different dictionary if it wishes, which will be used as the cleaned_data.
You could do something like this,
def clean(self, cleaned_data):
post_image = cleaned_data.get("post_image")
height_image = cleaned_data.get("height_image")
#do_your_thing
return cleaned_data
I need to make a form, which have 1 select and 1 text input. Select must be taken from database.
model looks like this:
class Province(models.Model):
name = models.CharField(max_length=30)
slug = models.SlugField(max_length=30)
def __unicode__(self):
return self.name
It's rows to this are added only by admin, but all users can see it in forms.
I want to make a ModelForm from that. I made something like this:
class ProvinceForm(ModelForm):
class Meta:
CHOICES = Province.objects.all()
model = Province
fields = ('name',)
widgets = {
'name': Select(choices=CHOICES),
}
but it doesn't work. The select tag is not displayed in html. What did I wrong?
UPDATE:
This solution works as I wanto it to work:
class ProvinceForm(ModelForm):
def __init__(self, *args, **kwargs):
super(ProvinceForm, self).__init__(*args, **kwargs)
user_provinces = UserProvince.objects.select_related().filter(user__exact=self.instance.id).values_list('province')
self.fields['name'].queryset = Province.objects.exclude(id__in=user_provinces).only('id', 'name')
name = forms.ModelChoiceField(queryset=None, empty_label=None)
class Meta:
model = Province
fields = ('name',)
Read Maersu's answer for the method that just "works".
If you want to customize, know that choices takes a list of tuples, ie (('val','display_val'), (...), ...)
Choices doc:
An iterable (e.g., a list or tuple) of
2-tuples to use as choices for this
field.
from django.forms.widgets import Select
class ProvinceForm(ModelForm):
class Meta:
CHOICES = Province.objects.all()
model = Province
fields = ('name',)
widgets = {
'name': Select(choices=( (x.id, x.name) for x in CHOICES )),
}
ModelForm covers all your needs (Also check the Conversion List)
Model:
class UserProvince(models.Model):
user = models.ForeignKey(User)
province = models.ForeignKey(Province)
Form:
class ProvinceForm(ModelForm):
class Meta:
model = UserProvince
fields = ('province',)
View:
if request.POST:
form = ProvinceForm(request.POST)
if form.is_valid():
obj = form.save(commit=True)
obj.user = request.user
obj.save()
else:
form = ProvinceForm()
If you need to use a query for your choices then you'll need to overwrite the __init__ method of your form.
Your first guess would probably be to save it as a variable before your list of fields but you shouldn't do that since you want your queries to be updated every time the form is accessed. You see, once you run the server the choices are generated and won't change until your next server restart. This means your query will be executed only once and forever hold your peace.
# Don't do this
class MyForm(forms.Form):
# Making the query
MYQUERY = User.objects.values_list('id', 'last_name')
myfield = forms.ChoiceField(choices=(*MYQUERY,))
class Meta:
fields = ('myfield',)
The solution here is to make use of the __init__ method which is called on every form load. This way the result of your query will always be updated.
# Do this instead
class MyForm(forms.Form):
class Meta:
fields = ('myfield',)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# Make the query here
MYQUERY = User.objects.values_list('id', 'last_name')
self.fields['myfield'] = forms.ChoiceField(choices=(*MYQUERY,))
Querying your database can be heavy if you have a lot of users so in the future I suggest some caching might be useful.
the two solutions given by maersu and Yuji 'Tomita' Tomita perfectly works, but there are cases when one cannot use ModelForm (django3 link), ie the form needs sources from several models / is a subclass of a ModelForm class and one want to add an extra field with choices from another model, etc.
ChoiceField is to my point of view a more generic way to answer the need.
The example below provides two choice fields from two models and a blank choice for each :
class MixedForm(forms.Form):
speaker = forms.ChoiceField(choices=([['','-'*10]]+[[x.id, x.__str__()] for x in Speakers.objects.all()]))
event = forms.ChoiceField(choices=( [['','-'*10]]+[[x.id, x.__str__()] for x in Events.objects.all()]))
If one does not need a blank field, or one does not need to use a function for the choice label but the model fields or a property it can be a bit more elegant, as eugene suggested :
class MixedForm(forms.Form):
speaker = forms.ChoiceField(choices=((x.id, x.__str__()) for x in Speakers.objects.all()))
event = forms.ChoiceField(choices=(Events.objects.values_list('id', 'name')))
using values_list() and a blank field :
event = forms.ChoiceField(choices=([['','-------------']] + list(Events.objects.values_list('id', 'name'))))
as a subclass of a ModelForm, using the one of the robos85 question :
class MixedForm(ProvinceForm):
speaker = ...
Even though a field is marked as 'editable=False' in the model, I would like the admin page to display it. Currently it hides the field altogether.. How can this be achieved ?
Use Readonly Fields. Like so (for django >= 1.2):
class MyModelAdmin(admin.ModelAdmin):
readonly_fields=('first',)
Update
This solution is useful if you want to keep the field editable in Admin but non-editable everywhere else. If you want to keep the field non-editable throughout then #Till Backhaus' answer is the better option.
Original Answer
One way to do this would be to use a custom ModelForm in admin. This form can override the required field to make it editable. Thereby you retain editable=False everywhere else but Admin. For e.g. (tested with Django 1.2.3)
# models.py
class FooModel(models.Model):
first = models.CharField(max_length = 255, editable = False)
second = models.CharField(max_length = 255)
def __unicode__(self):
return "{0} {1}".format(self.first, self.second)
# admin.py
class CustomFooForm(forms.ModelForm):
first = forms.CharField()
class Meta:
model = FooModel
fields = ('second',)
class FooAdmin(admin.ModelAdmin):
form = CustomFooForm
admin.site.register(FooModel, FooAdmin)
Add the fields you want to display on your admin page.
Then add the fields you want to be read-only.
Your read-only fields must be in fields as well.
class MyModelAdmin(admin.ModelAdmin):
fields = ['title', 'author', 'published_date', 'updated_date', 'created_date']
readonly_fields = ('updated_date', 'created_date')
You could also set the readonly fields as editable=False in the model (django doc reference for editable here). And then in the Admin overriding the get_readonly_fields method.
# models.py
class MyModel(models.Model):
first = models.CharField(max_length=255, editable=False)
# admin.py
class MyModelAdmin(admin.ModelAdmin):
def get_readonly_fields(self, request, obj=None):
return [f.name for f in obj._meta.fields if not f.editable]
With the above solution I was able to display hidden fields for several objects but got an exception when trying to add a new object.
So I enhanced it like follows:
class HiddenFieldsAdmin(admin.ModelAdmin):
def get_readonly_fields(self, request, obj=None):
try:
return [f.name for f in obj._meta.fields if not f.editable]
except:
# if a new object is to be created the try clause will fail due to missing _meta.fields
return ""
And in the corresponding admin.py file I just had to import the new class and add it whenever registering a new model class
from django.contrib import admin
from .models import Example, HiddenFieldsAdmin
admin.site.register(Example, HiddenFieldsAdmin)
Now I can use it on every class with non-editable fields and so far I saw no unwanted side effects.
You can try this
#admin.register(AgentLinks)
class AgentLinksAdmin(admin.ModelAdmin):
readonly_fields = ('link', )