Django models and views - python

I am trying to create my first project. Like Stack Overflow questions and answers on specific theme. I create my own user by AbstractBaseUser. And now I want to create Question and Answer model.
My model:
class Question(models.Model):
text = models.TextField()
title = models.CharField(max_length=200)
date = models.DateTimeField(default=datetime.datetime.now)
author = models.ForeignKey(CustomUser)
def __str__(self):
return self.title
class Answer(models.Model):
text = models.TextField()
date = models.DateTimeField(default=datetime.datetime.now)
likes = models.IntegerField(default=0)
author = models.ForeignKey(CustomUser)
question = models.ForeignKey(Question)
class Tags(models.Model):
TYPE_OF_TAGS = (
('First tag', 'First'),
('Second tag', 'Second'),
('Third tag', 'Third'),
)
type_of_tag = models.CharField(max_length=12, choices=TYPE_OF_TAGS, blank=True)
question = models.ManyToManyField(Question)
my views:
def question(request):
args = {}
args.update(csrf(request))
args['form'] = QuestionForm()
args['profile'] = CustomUser.objects.filter(pk = request.user.pk)
args['author'] = Question()
if request.POST:
args['form'] = QuestionForm(request.POST)
obj = args['form'].save(commit=False)
obj.save()
args['author'].author = args['profile']
args['author'].save()
return redirect(reverse(question))
return render(request, 'questions.html', args)
I create first view for answer, and I have error when I send form:
null value in column "author_id" violates not-null constraint
I think I'm going in the wrong direction. And I have bad models and bad views. Why I have this error and what wrong with my models?

If your business rules don't allow to have null author on a question, you must set the author value to your obj before saving it.
Something like:
def question(request):
args = {}
args.update(csrf(request))
args['form'] = QuestionForm()
args['profile'] = CustomUser.objects.filter(pk = request.user.pk)
if request.POST:
args['form'] = QuestionForm(request.POST)
obj = args['form'].save(commit=False)
obj.author = args['profile']
obj.save()
return redirect('your_redirect_url')
return render(request, 'questions.html', args)
You have another option:
You can pass to the QuestionForm an initial dictionary of:
{
'author' : CustomUser.objects.filter(pk = request.user.pk)
}
Something like:
def question(request):
args = {}
args.update(csrf(request))
args['form'] = QuestionForm(initial={
'author': CustomUser.objects.filter(pk = request.user.pk)
})
if request.POST:
args['form'] = QuestionForm(request.POST)
obj = args['form'].save()
return redirect('your_redirect_url')
return render(request, 'questions.html', args)
NOTE: It's important to render in your questions.html template, a hidden field for the author value, so it is included in the POST data.

Use null = True for Foreign key fields, that can be null.
class Question(models.Model):
#...
author = models.ForeignKey(CustomUser, null = True, blank = True)
Otherwise, specify the value of author when saving the model in first place, which you are doing erroneously. I'm unable to understand what does args['author'] = Question() means? You should do something on the lines of
args['author'] = CustomUser() # in your question view
instead.

Related

Django is not populating correctly an specific form using a Queryset

I have created two models Leads and Deals, and I have coded some logic such that if you click a button the Lead becomes a Deal, so what I want it is that a new form is presented to the user but that form already contains the information from the Leads model.
#login_required
def close_lead(request):
if request.method == 'POST':
deal_form = DealForm(request.POST)
if deal_form.is_valid():
deal_form.save()
messages.success(request, 'You have successfully updated the status from open to Close')
id = request.GET.get('project_id', '')
obj = Leads.objects.get(project_id=id)
obj.status = "Closed"
obj.save(update_fields=['status'])
return HttpResponseRedirect(reverse('dashboard'))
else:
messages.error(request, 'Error updating your Form')
else:
id = request.GET.get('project_id', '')
obj = get_object_or_404(Leads, project_id=id)
print(obj.expected_revenue)
form = NewDealForm(request.POST or None, instance=obj)
return render(request,
"account/close_lead.html",
{'form':form})
I have done some debug and printed to the console the queryset and the information is fine, so the queryset is no the problem, the problem is that the NewForm doesn't prepopulate the new values.
models.py (only 2 models shown)
class Leads(models.Model):
CHOICES = (
('Illumination Studies','Illumination Studies'),
('Training','Training'),
('Survey Design','Survey Design'),
('Software License','Software License')
)
STATUS = (('Open','Open'),
('Closed','Closed'),
('Canceled', 'Canceled')
)
project_id = models.BigAutoField(primary_key=True)
company = models.ForeignKey(Company, on_delete=models.CASCADE)
agent = models.ForeignKey(Profile, on_delete=models.CASCADE, default="agent")
created_at = models.DateTimeField(auto_now_add=True)
point_of_contact = models.ForeignKey(Client, on_delete=models.CASCADE)
expected_revenue = MoneyField(max_digits=14, decimal_places=2, default_currency='USD')
expected_licenses = models.IntegerField(blank=True)
country = CountryField(blank_label='(select country)')
status = models.CharField(max_length=10,choices=STATUS)
estimated_closing_date = models.DateField(blank=True)
services = models.CharField(max_length=20,choices=CHOICES)
def __str__(self):
return f'{self.company}'
class Deal(models.Model):
project_id = models.ForeignKey(Leads, on_delete=models.CASCADE, default='id')
agent = models.ForeignKey(Profile, on_delete=models.CASCADE, default="agent")
service = models.ForeignKey(Leads, on_delete=models.CASCADE, related_name='service')
closing_date = models.DateField(auto_now_add=True)
client = models.ForeignKey(Client, on_delete=models.CASCADE,default='client')
licenses = models.ForeignKey(Leads,on_delete=models.CASCADE, related_name='licenses')
revenue = MoneyField(max_digits=14, decimal_places=2, default_currency='USD')
comments = models.TextField(blank=True,null=True)
Now, it could be that I have to inherit from a different form?
forms.py (only NewDealForm)
class NewDealForm(forms.ModelForm):
class Meta:
model = Deal
fields = ['agent','client','project_id','service', 'licenses','revenue', 'comments']
Obviously, worst-case scenario is to create a dictionary to extract the data from the queryset and then pass it to the form, but I'm sure Django has a more elegant way to handle this process.
Well, I guess sometimes Stack Overflow pushes you to solve your own issues, this is the solution.
Essentially, the initial=queryset value was not initializing the form mainly because I have very specific relationships in my model, so what I did is to create a dictionary (key:value) with the form field as key, and my queryset from my model as the value, the code is as below:
'''
def close_lead(request):
if request.method == 'POST':
deal_form = DealForm(request.POST)
if deal_form.is_valid():
deal_form.save()
messages.success(request, 'You have successfully updated the status from open to Close')
id = request.GET.get('project_id', '')
obj = Leads.objects.get(project_id=id)
obj.status = "Closed"
obj.save(update_fields=['status'])
return HttpResponseRedirect(reverse('dashboard'))
else:
messages.error(request, 'Error updating your Form')
else:
id = request.GET.get('project_id', '')
obj = get_object_or_404(Leads, project_id=id)
m = obj.__dict__
keys = Leads.objects.get(project_id=m['project_id'])
form_dict = {'project_id':keys.project_id,
'agent':keys.agent,
'client':keys.point_of_contact,
'company':keys.company,
'service':keys.services
}
form = NewDealForm(request.POST or None,initial = form_dict)
return render(request,
"account/close_lead.html",
{'form':form})
'''
As you can see, I create an object dictionary because the forms are different, so they share some common values not all, and then I simply adapt the dictionary, nice and easy, but I somehow expected that Django somehow finds relationships by name?, but maybe the batteries are not included for this.

Django - NOT NULL constraint failed

I'm currently working on a Django app that will parse the contents of an uploaded log file to the associated database in my Django project. I've managed to get it all running as expected except it won't associate my uploaded data with the model's ForeignKey. I can assign null=True which resolves the integrity error but then of course, it doesn't assign any of the uploaded data to that ForeignKey. Here's the code:
models.py
class Case(models.Model):
case_ref = models.CharField(max_length=8)
oic = models.CharField(max_length=50)
subject = models.CharField(max_length=100)
submitted_date = models.DateTimeField(default=datetime.now, blank=True)
def get_absolute_url(self):
return reverse('case_list', kwargs={'pk': self.pk})
def __str__(self):
return self.case_ref + " " + self.subject
class TeamviewerLogs(models.Model):
case = models.ForeignKey(Case, on_delete=models.DO_NOTHING)
teamviewer_id = models.IntegerField()
teamviewer_name = models.TextField()
connection_start = models.TextField()
connection_end = models.TextField()
local_user = models.TextField()
connection_type = models.TextField()
unique_id = models.TextField()
def get_absolute_url(self):
return reverse('case_list', kwargs={'pk': self.pk})
def __str__(self):
return str(self.teamviewer_id) + " - " + str(self.teamviewer_id)
forms.py
class UploadLog(forms.ModelForm):
file = forms.FileField()
class Meta:
model = TeamviewerLogs
fields = [
'file'
]
views.py
def add_logs(request, pk):
case = get_object_or_404(Case, pk=pk)
if request.method == 'POST':
form = UploadLog(request.POST, request.FILES)
if form.is_valid():
teamviewer = form.save(commit=False)
teamviewer.case = case
log_file = request.FILES['file']
log_file = filter(None, (line.rstrip() for line in log_file))
for lines in log_file:
split = lines.decode('utf-8').split('\t')
teamviewer_id = split[0]
teamviewer_name = split[1]
connection_start = split[2]
connection_end = split[3]
local_user = split[4]
connection_type = split[5]
unique_id = split[6]
teamviewer = TeamviewerLogs(teamviewer_id=teamviewer_id, teamviewer_name=teamviewer_name,
connection_start=connection_start, connection_end=connection_end,
local_user=local_user, connection_type=connection_type, unique_id=unique_id)
teamviewer.save()
return redirect('tv_log_details', pk=case.pk)
form.save()
else:
form = UploadLog()
return render(request, 'teamviewer/add_logs.html', {'form': form})
But when I click to upload the file I'm hit with:
When it tries to execute teamviewer.save().
I've been trying to resolve this issue for hours and have tried so many different variations of answers from Stackoverflow or previous code I've used that has worked for different models but I've hit a brick wall...hard!
Any help anyone can offer would be greatly appreciated.
Ok, so here's an example of the concept I've suggested in the comments.
I've got a view which passes some data to the a form;
class ListingDetailView(DetailView):
""" Listing detail page """
model = Listing
template_name = 'listing.html'
def get_form_kwargs(self):
"""Return the kwargs for the form"""
kwargs = {}
initial = {
'listing': self.object,
}
kwargs['initial'] = initial
return kwargs
def get_form(self):
form = ApplicationSignupForm(
**self.get_form_kwargs()
)
return form
def get_context_data(self, **kwargs):
""" Add our form to the context """
context = super().get_context_data(**kwargs)
context['form'] = self.get_form()
return context
The form then makes use of that initial data and sets the field it relates to as hidden. I don't validate this data, but I'll try to show how you might do that;
class ApplicationSignupForm(forms.ModelForm):
class Meta:
""" Setup the form """
fields = (
'listing',
...
)
model = Application
widgets = {
'listing': forms.HiddenInput()
}
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
initial_data = kwargs['initial']
self.listing = initial_data.get('listing')
def clean(self):
"""
Custom form cleaning
"""
cleaned_data = super().clean()
listing = cleaned_data.get('listing')
if listing != self.listing:
self.add_error('listing', "You can't modify this value")
return cleaned_data

modify unique_together bound form django

I'm trying to modify an existing row of my database, it's a from an intermediary table named "CharacterSkill" with an unique together constraint :
models.py
class CharacterSkill(models.Model):
character = models.ForeignKey(Character, on_delete=models.CASCADE)
level = models.IntegerField(default=0)
skill = models.ForeignKey(Skill, on_delete=models.CASCADE)
class Meta:
unique_together = ("character","skill")
I did a form to change the level but I'm unable to save the form, I have two errors messages from both fields "character" & "skill":
Select a valid choice. That choice is not one of the available choices.
Can you help on that please ? :)
My form :
class SkillCreateForm(forms.ModelForm):
class Meta:
model = CharacterSkill
fields = ('skill','level','character',)
my view :
def skill_update(request,skillpk,instancepk):
form = SkillCreateForm(request.POST)
user = User.objects.get (id = request.user.id)
instance = Character.objects.get (id = instancepk)
skill = CharacterSkill.objects.get(id = skillpk)
data = {'character' : instance,
'skill' : skill.skill,
'level' : skill.level,
}
if form.is_valid():
form.save()
return redirect('persomaker:skill_list', instance.id)
else:
form = SkillCreateForm(data)
#form.fields['skill'].widget = HiddenInput()
#form.fields['character'].widget = HiddenInput()
return render(request, 'character/create_skill.html',
{'instance':instance,
'skill':skill,
'form': form,})
based on a book, I changed the way I bounded the form to use instance :
def skill_update(request,skillpk,instancepk):
user = User.objects.get (id = request.user.id)
instance = Character.objects.get (id = instancepk)
skill = CharacterSkill.objects.get(id = skillpk)
if request.method == "POST":
form = SkillModifyForm(request.POST,instance = skill,)
print (skill)
if form.is_valid():
form.save()
return redirect('persomaker:skill_list', instance.id)
else:
form = SkillModifyForm(instance = skill,)
return render(request, 'character/create_skill.html',
{'instance':instance,
'skill':skill,
'form': form,})

Django: Setting values of certain attributes in the database using views?

I have a form in my application which has a hidden form field, the value of which I want to set in my corresponding view after submitting the form.
forms.py
class EvangelizedForm(forms.ModelForm):
first_name = forms.CharField(help_text="First Name")
last_name = forms.CharField(help_text="Last Name")
email = forms.CharField(help_text="Email ID")
mobile_no = forms.CharField(help_text="Mobile number")
twitter_url = forms.CharField(help_text="Twitter URL")
twitter_followers = forms.CharField(widget = forms.HiddenInput()) #Hidden form field
class Meta:
model = Evangelized
fields = ('first_name','last_name', 'twitter_url', 'email', 'mobile_no')
models.py
class Evangelized(models.Model):
first_name = models.CharField(max_length=128)
last_name = models.CharField(max_length=128)
email = models.EmailField()
mobile_no = models.CharField(unique=True, max_length = 10, validators=[RegexValidator(regex='^\w{10}$', message='Mobile number should be strictly of 10 digits.')])
twitter_url = models.CharField(unique=True, max_length=128)
twitter_followers = models.CharField(max_length = 128)
views.py
def fillform(request):
follower_count = '250'
if request.method == 'POST':
form = EvangelizedForm(request.POST)
if form.is_valid():
form.fields['twitter_followers'] = follower_count
form.save(commit=True)
return index(request)
else:
form.errors
else:
#form = EvangelizedForm()
if request.user.is_authenticated():
form = EvangelizedForm(initial={'first_name': request.user.first_name,
'twitter_url': 'https://twitter.com/' + request.user.username,
'last_name': request.user.last_name})
else:
form = EvangelizedForm()
context = RequestContext(request,
{'request': request,
'user': request.user, 'form':form})
#return render(request, 'rango/fillform.html', {'form': form, 'context_instance':context})
return render_to_response('rango/fillform.html',
context_instance=context)
Basically, I'm trying to set the value of twitter_followers (which is a hidden form field in forms.py) in my index view, by:
follower_count = '250'
..
..
form.fields['twitter_followers'] = follower_count
By doing this, I'm expecting the value of 'twitter_followers' in the database after submitting the form to be '250'. However, this approach doesn't seem to be working.
What's the right way to set values to certain attributes in the database manually using views?
You need to set it on the model instance, which is the result of form.save. That's the main reason for the commit argument in the first place.
if form.is_valid()
obj = form.save(commit=True)
obj.twitter_follower = follower_count
obj.save()
You can override the save method of the form, with something like this:
def save(self, *args, **kwargs)
twitter_followers = kwargs.pop('twitter_followers', 0)
self.instance.twitter_followers = twitter_followers
super(Evangelized, self).save(args, kwargs)
And then in the view just have to call in this way:
form.save(twitter_followers=250)

Django: Edit ModelForm using AutoField

I'm trying to make a view where the user can edit DB records through a form in a template. I've searched a lot of web pages (and Django docs as well) where they teach how to make these views, but they always use the "id" that Django generates for each Model. In this particular Model, I have to use an AutoField to override the "id". Is there a way to use this AutoField as an "id" of the record with Django?
Here's my complete model:
class T031003 (models.Model):
C003IDCD = AutoField(primary_key=True)
C003INST = models.IntegerField(unique=True) #usar AutoSlug
C003TPCD = models.CharField(max_length=1)
C003CHCD = models.CharField(max_length=14)
C003MTR = models.CharField(max_length=30, blank=True, null=True)
C003CTCD = models.CharField(max_length=3)
C003RZSC = models.CharField(max_length=60, blank=True, null=True)
C003EML = models.EmailField(max_length = 254, blank=True, null=True)
C003LOGA = models.CharField(max_length=20)
C003LOGB = models.DateTimeField()
C003LOGD = models.CharField(max_length=15, blank=True, null=True)
C003LOGF = models.CharField(max_length=20, blank=True, null=True)
def __unicode__(self):
return '%s' % self.C003MTR
class T031003Form(ModelForm):
class Meta:
model = T031003
ordering = ["-C003MTR"]
exclude = ('C003LOGA','C003LOGB','C003LOGD','C003LOGE','C003LOGF')
And here's the view I tried to do, but it gives me the error "No T031003 matches the given query." and it's right, since there is no "id" in the table:
def t031003form_edit(request, id=None):
pin = get_object_or_404(T031003, pk=id)
form = T031003Form(request.POST or None, instance=pin)
if request.method == 'POST':
if form.is_valid():
form = form.save(False)
form.C003LOGA = request.user
form.C003LOGB = datetime.date.today()
form.C003LOGD = request.META['REMOTE_ADDR']
form.C003LOGF = request.META['USERDOMAIN']
form.save()
form = T031003Form()
else:
return HttpResponseRedirect('/erro/')
return render_to_response('T031003Form_edit.html', {'form': form,}, context_instance=RequestContext(request))
Any help would be very appreciated!
If a model has an AutoField — an auto-incrementing primary key — then that auto-incremented value will be calculated and saved as an attribute on your object the first time you call save():
>>> b2 = Blog(name='Cheddar Talk', tagline='Thoughts on cheese.')
>>> b2.id # Returns None, because b doesn't have an ID yet.
>>> b2.save()
>>> b2.id # Returns the ID of your new object.
There's no way to tell what the value of an ID will be before you call save(), because that value is calculated by your database, not by Django.
ref : https://docs.djangoproject.com/en/dev/ref/models/instances/?from=olddocs
Well, thanks to the help from a close friend, I could do the trick using formsets. Here's the view:
def t031002form_edit(request, id_auto):
j = get_object_or_404(T031002, pk=id_auto)
T031003FormSet = modelformset_factory(T031002, can_delete=True, max_num=1)
if request.method == 'POST':
form = T031002FormSet(request.POST or None, request.FILES or None, queryset=T031002.objects.filter(pk=id_auto))
if form.is_valid():
instance = form.save(commit=False)
form.C003LOGA = request.user
form.C003LOGB = datetime.date.today()
form.C003LOGD = request.META['REMOTE_ADDR']
form.C003LOGF = request.META['USERDOMAIN']
for reform in instance:
reform.save()
else:
return HttpResponseRedirect('/erro/')
else:
form = T031002FormSet(queryset=T031002.objects.filter(pk=id_auto))
return render_to_response(('T031002Form_edit.html'), {'form': form,}, context_instance=RequestContext(request))
So, with formsets, you can work nicely and with no worries. Hope it helps others with this same questioning.

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