Develop Reference

Django: How to write a function based view used for URL with parameter

I am learning Django, using function based views, and I am struggling with the following:
I have this path in urls.py
path('user/<str:username>',views.UserProjectList,name='user-projects')
that is supposed to show all the projects of the particular user (client). In order to reach it, username should be parameter of the function based view, however I am struggling how to write such view...
I have this:
def UserProjectList(request,username):
user = User.objects.get(username=username) #THIS IS WRONG and should return id of the user
#user = User.objects.filter(username=username) #also wrong
tag_list = ProjectTagsSQL.objects.all() #ProjectTagsSQL and ProjectSQL are connected
project_list = ProjectSQL.objects.filter(client=user) #ProjectSQL table has column client_id (pk is id in User) and table contains all the projects
context = {
'tagy' : tag_list,
'projecty' : project_list
}
return render(request, 'home_page/user_projects.html', context) #SHOULD THE PARAMETER BE INCLUDED HERE?
I tried to inspire with the code from class based view I found on the internets (thats is working for me but i didnt manage to connect it with ProjectTagsSQL as i managed in FBV, but that's a different problem) but i didnt manage
class UserProjectListView(ListView):
model = ProjectSQL
template_name = 'home_page/user_projects.html'
context_object_name = 'data'
def get_queryset(self):
user = get_object_or_404(User, username=self.kwargs.get('username'))
return ProjectSQL.objects.filter(client=user)
Could someone help me how to deal with such function based view please? As this solution its not working (will return nothing for any user)
Here is also the ProjectSQL model (and ProjectTagsSQL model) :
class ProjectSQL(models.Model):
id = models.AutoField(primary_key=True)
country = models.TextField()
city = models.TextField()
time_added = models.DateTimeField(default=timezone.now)
start_date = models.DateField()
end_date = models.DateField()
client = models.ForeignKey(User, on_delete=models.CASCADE)
class Meta:
managed = False #https://docs.djangoproject.com/en/4.0/ref/models/options/
db_table = 'project'
class ProjectTagsSQL(models.Model):
id = models.IntegerField(primary_key=True)
project = models.ForeignKey(ProjectSQL, on_delete=models.CASCADE)
tag = models.ForeignKey(ProjectTagSQL, on_delete=models.CASCADE)
class Meta:
managed = False # https://docs.djangoproject.com/en/4.0/ref/models/options/
db_table = 'project_tags'

You need to write user.id so:
from django.shortcuts import get_object_or_404
def UserProjectList(request,username):
user = get_object_or_404(User,username=username)
tag_list = ProjectTagsSQL.objects.all()
project_list = ProjectSQL.objects.filter(client=user.id)
context = {
'tagy' : tag_list,
'projecty' : project_list
}
return render(request, 'home_page/user_projects.html', context)
Also, try to check template variables' name, whether you used same or not.
Note: Always append / at the end of every route so it should be path('user/<str:username>/'....
Note: Function based views are generally written in snake_case so it is better to name it as user_project_list instead of UserProjectList.

Formsets + Many to Many Relationship Problem

I have partially implemented the formsets + many to many relationship feature with an Invoice and Inventory Model.
My problem is the form does not show the available Inventory (even though they exist).
See problem here:
https://www.dropbox.com/s/mtqkfee2pisyh5a/dj005_formset_many_to_many_relationship_working.jpg?dl=0
Here is the working code:
# MODELS.PY
class Invoice_Test_M2M(models.Model):
id = models.BigAutoField(primary_key=True)
ref_num = models.CharField(max_length=100)
def __str__(self):
return self.ref_num
class Inventory_Test_M2M(models.Model):
id = models.BigAutoField(primary_key=True)
inventory_name = models.CharField(blank=True, max_length=100)
invoice = models.ManyToManyField('Invoice_Test_M2M', through= "Invoice_Inventory_Through")
def __str__(self):
return self.inventory_name
class Invoice_Inventory_Through(models.Model):
invoice = models.ForeignKey(Invoice_Test_M2M, on_delete=models.CASCADE)
inventory = models.ForeignKey(Inventory_Test_M2M, on_delete=models.CASCADE)
price = models.DecimalField(max_digits=9, decimal_places=2, blank=True, null=True)
quantity = models.DecimalField(max_digits=9, decimal_places=2, blank=True, null=True)
amount = models.DecimalField(max_digits=9, decimal_places=2, blank=True, null=True)
# FORMS.PY
Inventory_TestLineItem_M2M_Formset = inlineformset_factory(Invoice_Test_M2M, Invoice_Inventory_Through, fields = '__all__', exclude=[], can_delete=True)
# VIEWS.PY
class Invoice_M2M_CreateView(CreateView):
model = Invoice_Test_M2M
fields = '__all__'
def get_context_data(self, **kwargs):
context = super(Invoice_M2M_CreateView, self).get_context_data(**kwargs)
if self.request.POST:
context['track_formset'] = Inventory_TestLineItem_M2M_Formset(self.request.POST)
else:
context['track_formset'] = Inventory_TestLineItem_M2M_Formset()
return context
def form_valid(self, form):
context = self.get_context_data(form=form)
formset = context['track_formset']
if formset.is_valid():
response = super().form_valid(form)
formset.instance = self.object
formset.save()
return response
else:
return super().form_invalid(form)
Is there a way around this?
PS. INTERESTINGLY, if I just use a pseudo many to many MODEL (i.e. using a foreign field and not a many to many field). It works.
You can see it working here:
https://www.dropbox.com/s/32x84k8roa88jvf/dj005_formset_many_to_many_relationship_working_B.jpg?dl=0
So why not use this method? The main reason is the M2M has a built-in API in showing its relevant members (i.e. Shows the inventories of a specific Invoice). In the method above, I am under the impression I have to do it manually.
P.P.S. Related Stackoverflow post. I already implemented the solutions but I still get the same problem:
pendant to inline formsets for many-to-many relations
Accessing Many to Many "through" relation fields in Formsets

And just like that. After posting the question, I found the answer.
Stupid me.
Basically, the code I posted above works.
The problem is I created a new model so technically speaking its empty so I couldn't find them in my drop down list.

Customize foreign key dropdown in Django Admin Site

I'm having trouble finding the best way to override and add custom html to an edit/add model form in my Django admin site.
Here are the two models involved here:
Icon model used to store "Font Awesome" Icons:
class Icon(models.Model):
name = models.CharField(max_length=100, null=False)
style = models.CharField(max_length=10, choices=STYLE_CHOICES, null=False)
retired = models.BooleanField(default=False)
def delete(self):
self.retired = True
self.save()
objects = NotRetiredManager()
objects_deleted = DeletedManager()
def __str__(self):
return self.name
Workbook model that holds foreign key reference to the above Icon model:
class Workbook(models.Model):
client = models.ForeignKey(Client, on_delete=models.SET_NULL, null=True)
icon = models.ForeignKey(Icon, on_delete=models.SET_NULL, null=True, blank=True)
name = models.CharField(max_length=100)
workbookLink = models.CharField(max_length=1000)
retired = models.BooleanField(default=False)
def delete(self):
self.retired = True
self.save()
objects = NotRetiredManager()
objects_deleted = DeletedManager()
def __str__(self):
return self.name
Here are the overridden admin models for the above models:
class BaseAdmin(AdminImageMixin, admin.ModelAdmin):
def delete_queryset(self, request, queryset):
for obj in queryset:
obj.delete()
#admin.register(Workbook)
class WorkbookAdmin(BaseAdmin):
list_display = ("name", "client")
list_filter = (NameFilter, ClientNameFilter)
ordering = ("name", )
#admin.register(Icon)
class IconAdmin(BaseAdmin):
fields = ("name", "style", "icon_display")
list_display = ("icon_display", "name", "style" )
list_display_links = ("icon_display", "name")
list_filter = (NameFilter, )
ordering = ("name", )
def icon_display(self, obj):
return mark_safe(f'<i class="{obj.style}{obj.name}"></i>')
readonly_fields = ["icon_display"]
Here is a list display of some Icons I have in my database:
Currently, the add/edit page for a Workbook on my Admin Site looks like this:
I would like for that dropdown in that second screenshot to be customized similar to the "Icon Display" column in that first screenshot so that a user would choose from graphical list of icons as opposed to the default choicefield form containing the Icon names.
I've looked into the Django docs as well as similar questions on here such as this Similar Stack Overflow Question; however, I'm not fully understanding the proper way to implement something like this.
I hope the information I provided about my app is useful. Please let me know if you'd like me to provide any additional information, or add any clarifications!

Django 3 - Making Model's FK Dropdown Display Current User's Data Only

I'm creating my first app with Django and still have a lot to learn, but right now I am completely stuck and need some help. I have a model for Customers and Tickets. I have it so different users can save new customers/tickets and only view their data from the dashboard once logged in. However, when creating a new ticket, there is a dropdown option to select customer for the ticket - and the current user is able to see every users customers.
Here is the code, I'll share more code if needed, but I think this covers what I have going on...
forms.py
class TicketForm(ModelForm):
class Meta:
model = Ticket
fields = ['number', 'customer','date_created','work_description','mechanics','status']
views.py
def createTickets(request):
form = TicketForm()
if request.method == 'POST':
form = TicketForm(request.POST)
if form.is_valid():
newticket = form.save(commit=False)
newticket.shopowner = request.user
newticket.save()
return redirect('tickets')
context = {
'form': form
}
return render(request, 'createticket.html', context)
models.py
class Ticket(models.Model):
def default_number():
no = Ticket.objects.count()
return no + 1
shopowner = models.ForeignKey(User, on_delete=models.CASCADE, default=1)
number = models.CharField(max_length=30, unique=True, default= default_number)
customer = models.ForeignKey(Customer, default=1, on_delete= models.SET_DEFAULT, blank=True)
date_created = models.DateField(default=timezone.now)
work_description = models.TextField(verbose_name="Service Details: ")
mechanics = models.ForeignKey(Mechanic, default=1, on_delete=models.DO_NOTHING, blank=True, verbose_name="Mechanic")
status = models.BooleanField(default=True, verbose_name="Open Ticket")
class Meta:
verbose_name_plural = "Tickets"
I need the Customer foreignkey to only display customers of the current user (or 'shopowner') - same thing for mechanic and eventually vehicle but I can figure those out once I know how to get the customer input to display the correct data.

You'll need to customize your form a bit, in order to modify the queryset for that particular field. We also need to pass a user from the view:
forms.py
class TicketForm(ModelForm):
class Meta:
model = Ticket
fields = ['number', 'customer', 'date_created', 'work_description', 'mechanics', 'status']
def __init__(self, user=None, *args, **kwargs):
super().__init__(*args, **kwargs)
if user:
self.fields['customer'].queryset = Customer.objects.filter(shopowner=user)
views.py
def createTickets(request):
form = TicketForm(user=request.user)
# ...
Exactly how you define the queryset is going to depend on how you've defined the relationship between Customer and Shopowner, but this should give you the right approach.

Django Twitter clone. How to restrict user from liking a tweet more than once?

I'm not sure where to start. Right now, the user can press like as many times they want and it'll just add up the total likes for that tweet.
models.py
class Howl(models.Model):
author = models.ForeignKey(User, null=True)
content = models.CharField(max_length=150)
published_date = models.DateTimeField(default=timezone.now)
like_count = models.IntegerField(default=0)
rehowl_count = models.IntegerField(default=0)
def get_absolute_url(self):
return reverse('howl:index')
def __str__(self):
return self.content
views.py
class HowlLike(UpdateView):
model = Howl
fields = []
def form_valid(self, form):
instance = form.save(commit=False)
instance.like_count += 1
instance.save()
return redirect('howl:index')
Django Twitter clone. How to restrict user from liking a tweet more than once?

As well as tracking how many Likes a post has, you'll probably also want to track who has "Liked" each post. You can solve both of these problems by creating a joining table Likes with a unique key on User and Howl.
The unique key will prevent any User from doing duplicate likes.
You can do this in Django with a ManyToManyField, note that since this means adding a second User relationship to Howl, we need to disambiguate the relationship by providing a related_name
Eg:
class Howl(models.Model):
author = models.ForeignKey(User, null=True, related_name='howls_authored')
liked_by = models.ManyToManyField(User, through='Like')
# ...rest of class as above
class Like(models.Model):
user = models.ForeignKey(User)
howl = models.ForeignKey(Howl)
class Meta:
unique_together = (('user', 'howl'))
like_count count then becomes redundant, since you can use Howl.liked_by.count() instead.
The other benefit of this is that it allows you to store information about the Like - eg when it was added.

An idea could be adding a column to your table named likers and before incrementing like_counts check if the models.likers contains the new liker or not. If not increment the likes, if yes don't.

Changed liked_count in my models.py to
liked_by = models.ManyToManyField(User, related_name="likes")
views.py
class HowlLike(UpdateView):
model = Howl
fields = []
def form_valid(self, form):
instance = form.save(commit=False)
instance.liked_by.add(self.request.user)
instance.like_count = instance.liked_by.count()
instance.save()
return redirect('howl:index')
index.html
{{howl.liked_by.count}}