Django CBV form using list of objects - python

I am trying to create a form that is a list of cars with one field being a BooleanField. I want this to appear as a form with the BooleanField being a checkbox. If the user checks this, then the BooleanField will be set = True and something will happen when a POST occurs and the user is redirected to the next page.
model.py:
class Car(models.Model):
year = models.IntegerField()
make = models.CharField(max_length=30)
model = models.CharField(max_length=30)
send = models.BooleanField(default=False)
currenly the email.html looks like this:
<form action="" method="post">{% csrf_token %}
{% for car in object_list %}
<input type="checkbox" name="car" id="car{{ forloop.counter }}" value="{{ car.id }}">
<label for="car{{ forloop.counter }}">{{ car.year }} {{ car.make }} {{ car.model }}</label><br>
{% endfor %}
<input type="submit" value="Preview">
</form>
views.py
class Email(ListView):
model = Car
template_name = 'cars/email.html'
Suggestions?

I ended up adding a post() function to the ListView which processes the form data, but I am having trouble redirecting without a valid HttpResponse object and am getting an error when one of the boxes isn't checked in the form. Here is the additional post() code that I added for the time being:
def post(self, request, *args, **kwargs):
cars = Car.objects.all() # initially reset "self.send" field == False
for i in range(len(cars)):
cars[i].send = False
cars[i].save()
cars = Car.objects.filter(id__in=request.POST.getlist('car'))
for i in cars:
i.send = True
i.save()
return HttpResponseRedirect(reverse('cars:email_preview'))
Any suggestions on how to make the form re-render with an error msg if no boxes are checked?
Thanks

Related

why my submit input isn't working in django?

I have a form so an user can ask for a loan and it will tell them if it´s approved or not. The problem is not the logic, it´s the submit input that doesn't work. It will not save the form in the database or show me the errors because of the submit input. Maybe is something wrong with the succes_url? I don't know, but here's my code:
views.py:
#don't worry about the logic part of the form, it's just to show how it´s supposed to work
class LoanRequest(LoginRequiredMixin, generic.CreateView):
form_class = LoanForm
success_url = reverse_lazy('Prestamos')
template_name = 'Prestamos/template/Prestamos/prestamos.html'
def form_valid(self, form):
user = self.request.user
cliente = Cliente.objects.get(user_id = user.id)
if not cliente.approve_loan(form.cleaned_data.get('loan_total')):
form.add_error(field=None, error='loan not approved')
return self.form_invalid(form)
else:
form.instance.customer_id = cliente
super(LoanRequest, self).form_valid(form)
return render(self.request, 'Prestamos/template/Prestamos/prestamos.html', context={'form': form, 'success_msg': 'loan approved!'})
urls.py:
urlpatterns = [
path('prestamos/', views.LoanRequest.as_view(), name = 'prestamos'),
]
forms.py:
class LoanForm(forms.ModelForm):
class Meta:
model = Prestamo #loan in English
fields = ['loan_type', 'loan_total', 'loan_date']
and the template:
<div class="container">
{%if success_msg%}
<p class="alert alert-success">{{success_msg}}</p>
{%endif%}
<form action="" method="POST">
{%csrf_token%}
{%for field in form%}
<div class="form-group">
<label for="{{field.label}}">{{field.label}}</label>
{{field}}
</div>
{%for error in field.errors%}
<p>{{error}}</p>
{%endfor%}
{%endfor%}
<input type="submit" value="request"></input>
</form>
</div>
models.py:
class Prestamo(models.Model):
loan_id = models.AutoField(primary_key=True)
loan_type = models.CharField(max_length=20,
choices = [('PERSONAL', 'PERSONAL'), ('HIPOTECARIO', 'HIPOTECARIO'), ('PRENDARIO', 'PRENDARIO')])
loan_date = models.DateField()
loan_total = models.IntegerField()
customer_id = models.IntegerField()
class Meta:
db_table = 'prestamo'
Well, <input> is an empty tag, it does not contain anything, so don't close it.
Additionally, I'd recommend you to make gaps between template tags, like it should be {% endfor %} not {%endfor%}.
Also, remove the empty action attribute from form, as Django always take current page route if not mentioned or empty string.
Also use novalidate on form for rendering custom errors.
Try this template:
<div class="container">
{% if success_msg %}
<p class="alert alert-success">{{success_msg}}</p>
{% endif %}
<form method="POST" novalidate>
{% csrf_token %}
{% for field in form %}
<div class="form-group">
<label for="{{field.label}}">{{field.label}}</label>
{{field}}
</div>
{% for error in field.errors %}
<p>{{error}}</p>
{% endfor %}
{% endfor %}
<input type="submit" value="request">
</form>
</div>
Edit:
One mistake I could see the name for the view is prestamos and you have mentioned it as Prestamos, which is wrong.
So:
class LoanRequest(LoginRequiredMixin, generic.CreateView):
form_class = LoanForm
success_url = reverse_lazy('prestamos')
template_name = 'Prestamos/template/Prestamos/prestamos.html'

Manually rendered Django formset redirection problem at submition

I have the following models defined:
class Item(models.Model):
rfid_tag = models.CharField()
asset = models.OneToOneField('Assets', default=None, null=True,
on_delete=models.SET_DEFAULT,)
date = models.DateTimeField(name='timestamp',
auto_now_add=True,)
...
class Assets(models.Model):
id = models.AutoField(db_column='Id', primary_key=True)
assettag = models.CharField(db_column='AssetTag', unique=True, max_length=10)
assettype = models.CharField(db_column='AssetType', max_length=150)
...
class Meta:
managed = False
db_table = 'Assets'
ordering = ['assettag']
def __str__(self):
return f"{self.assettag}"
def __unicode__(self):
return f"{self.assettag}"
For which I have created the following form and formset:
class ItemDeleteForm(forms.ModelForm):
asset = forms.CharField(required=True,
help_text= "Item asset tag",
max_length=16,
label="AssetTag",
disabled=True,
)
delete = forms.BooleanField(required=False,
label="Delete",
help_text='Check this box to delete the corresponding item',
)
class Meta:
model = Item
fields = ['asset']
ItemDeleteMultiple = forms.modelformset_factory(model=Item,
form=ItemDeleteForm,
extra=0,
)
managed by the view:
class DeleteMultipleView(generic.FormView):
template_name = '*some html file*'
form_class = ItemDeleteMultiple
success_url = reverse_lazy('*app_name:url_name*')
def form_valid(self, form):
return super().form_valid(form)
And rendered in the template:
{% extends "pages/base.html" %}
{% block title %}
<title>Delete Multiple</title>
{% endblock %}
{% block content %}
<h1>Delete Multiple Items</h1>
<br>
<form class="ManualForm" action ="." method="POST"> {% csrf_token %}
{{ form.management_form }}
<table border="2">
<tr><th colspan="3" scope="row">Select Items to Delete</th></tr>
{% for item_form in form %}
<tr>
<td><label for="{{ item_form.asset.id_for_label }}">AssetTag {{forloop.counter}}:</label>
{% if item_form.non_field_errors %}
{{ item_form.non_field_errors }}
{% endif %}
{% if item_form.asset.errors %}
{{item_form.asset.errors}}
{% endif %}
</td>
<td>{{item_form.asset}}</td>
<td>{{item_form.delete}}
{% if item_form.delete.errors %}
{{item_form.delete.errors}}
{% endif %}
</td>
</tr>
{% endfor %}
</table>
<br>
<input class = "btn btn-success" type="submit" value="Delete Selected" />
Cancel
</form>
<form class="AutoForm" action ="." method="POST"> {% csrf_token %}
{{form.as_table}}
<input class = "btn btn-success" type="submit" value="Delete Selected" />
Cancel
</form>
{% endblock %}
When I submit AutoForm, everything is great. It takes me to app_name:url_name, but if I sumbit ManualForm I don't get redirected. It will simply clear all data and reload the form page with empty fields.
The HTTP POST response status code for AutoForm is 302, while for ManualForm is 200.
I don't understand how the template could influence the behavior of the url redirection. What am I doing wrong in the manual rendering of the formset?
It seems that adding:
{% for field in item_form.hidden_fields %}
{{field}}
{% endfor %}
under {% for item_form in form %} will solve the issue.
I didn't understand very well from the docs:
Looping over hidden and visible fields
If you’re manually laying out a form in a template, as opposed to
relying on Django’s default form layout, you might want to treat
< input type="hidden"> fields differently from non-hidden fields. For
example, because hidden fields don’t display anything, putting error
messages “next to” the field could cause confusion for your users – so
errors for those fields should be handled differently.
I just thought this is about errors, so I didn't care. But one of the first thing it says about forms is this:
As an example, the login form for the Django admin contains several
< input> elements: one of type="text" for the username, one of
type="password" for the password, and one of type="submit" for the
“Log in” button. It also contains some hidden text fields that the
user doesn’t see, which Django uses to determine what to do next.
It also tells the browser that the form data should be sent to the URL
specified in the < form>’s action attribute - /admin/ - and that it
should be sent using the HTTP mechanism specified by the method
attribute - post.
Maybe it will help someone else.

validate datetime input uniqueness in CreateView form

I have this model, and what I need is the time to be unique as it's a Reservation, so when I create a new reservation, how can I check if that time is already picked.
models.py
class Reserva(models.Model):
horario = models.DateTimeField(auto_now_add=False, auto_now=False)
cancha = models.ForeignKey('Cancha', on_delete=models.CASCADE)
lote = models.IntegerField()
views.py
class ReservasCreateView(generic.edit.CreateView):
model = Reserva
template_name = 'reservar.html'
fields = ['horario', 'cancha', 'lote']
reservation.html
<form method="post">
{% csrf_token %}
{{ form.as_p }}
<input type="submit" value="Reservar">
</form>
And another doubt I have, if I want to change some input types in the form, should I keep the default CreateView and modify it over the view, or create a custom form in forms.py and pass it as form_class. What's the recomendation? Thanks
You can force the creation of reservations's date to be unique in the database level by adding:
horario = models.DateTimeField(unique=True)
Or, you can override the form_valid() method in order to check if the date is picked or not and rise an exception or whatever you want:
from django.contrib import messages # better than raising an exception
from app_name import models # import your APP models
class ReservasCreateView(generic.edit.CreateView):
model = Reserva
template_name = 'reservar.html'
fields = ['horario', 'cancha', 'lote']
success_url = 'YOUR_SUCCESS_URL'
def form_valid(self, form):
date = form.cleaned_data.get('horario', None)
# check if the date is unique
# If we find the same date stored in the database
# we'll add a message to be rendered into the template
dates = models.Reserva.objects.filter(horario=date).first()
if dates:
messages.error(self.request, "This current date is not unique!")
return super().form_valid(form)
And then in your template you can add the messages framework like this example:
{% for message in messages %}
{{ message }}
{% endfor %}
<form method="post">
{% csrf_token %}
{{ form.as_p }}
<input type="submit" value="Reservar">
</form>
For more information you can visit the django official documentation

Using Django FormPreview the right way

My Goal
I have a django project with a form, and I want to display a preview page before the user submits.
The problem
I can display a preview page using a Django FormPreview, but not all form data is displayed properly. Specifically, if I have a field with choices, the string values of these choices aren't displayed. I'm also having problems applying template filters to date fields. The end result is that some data on the preview page is visible but other data is blank:
However, if I display the same data for posts that have actually been submitted, then everything displays properly:
My Code
models.py:
class Game(models.Model):
# Game Choices
FOOTBALL = 0
BASKETBALL = 1
TENNIS = 2
OTHER = 3
GAME_CHOICES = (
(FOOTBALL, 'Football'),
(BASKETBALL, 'Basketball'),
(TENNIS, 'Tennis'),
(OTHER, 'Other')
)
game_id = models.AutoField(primary_key=True)
location = models.CharField(max_length=200, verbose_name="Location")
game = models.IntegerField(choices=GAME_CHOICES, default=FOOTBALL)
game_date = models.DateField(verbose_name='Game Date')
forms.py
class GameForm(ModelForm):
class Meta:
model = Game
fields = (
'location',
'game',
'game_date'
)
I'm pretty sure that the problem is in my views.py: I'm not sure that I'm processing the POST request the right way to feed all data to the preview page.
views.py
def form_upload(request):
if request.method == 'GET':
form = GameForm()
else:
# A POST request: Handle Form Upload
form = GameForm(request.POST) # Bind data from request.POST into a GameForm
# If data is valid, proceeds to create a new game and redirect the user
if form.is_valid():
game = form.save()
return render(request, 'games/success.html', {})
return render(request, 'games/form_upload.html', {
'form': form,
})
preview.py
class GameFormPreview(FormPreview):
form_template = 'games/form_upload.html'
preview_template = 'games/preview.html'
def done(self, request, cleaned_data):
# Do something with the cleaned_data, then redirect
# to a "success" page.
return HttpResponseRedirect('/games/success')
form_upload.html
...
<form method="post">
{% csrf_token %}
<ul><li>{{ form.as_p }}</li></ul>
<button type="submit">Preview your post</button>
</form>
...
preview.html
{% load humanize %}
...
<h1>Preview your submission</h1>
<div>
<p>Location: {{ form.data.location }}</p>
<p>Game Date: {{ form.data.game_date|date:"l, F d, Y" }}</p>
<p>Game Type: {{ form.data.get_game_display }}</p>
</div>
<div>
<form action="{% url 'form_upload' %}" method="post">
{% csrf_token %}
{% for field in form %}
{{ field.as_hidden }}
{% endfor %}
<input type="hidden" name="{{ stage_field }}" value="2" />
<input type="hidden" name="{{ hash_field }}" value="{{ hash_value }}" />
<!-- Submit button -->
<button type="submit">Submit your post</button>
<!-- Go back button -->
<button type="submit">
<a href="{% url 'form_upload' %}"
onClick="history.go(-1);return false;" >
Go back and edit your post
</a>
</button>
</div>
</form>
</div>
...
Two issues
Essentially, I'm having these two issues:
String values for choices are not displayed. If I use the get_FOO_display() method in my preview.html template, it returns blank. However, if I use this in a page after the post has been submitted, it displays properly.
The humanize date filter doesn't work. If I apply a humanize filter ({{ form.data.game_date|date:"l, F d, Y" }}) in preview.html, it also displays blank. Again, this works for submitted posts.
My question essentially is: what's the right way to use the FormPreview here?
form.data does not have get_FOO_display attributes. When you access {{ form.data.get_game_display }} in the template, it fails silently and doesn't display anything.
The get_FOO_display are methods of the instance, so try this instead.
{{ form.instance.get_game_display }}
Wherever possible you should access data from form.cleaned_data (which is validated and 'cleaned') instead of form.data, which is the raw data submitted to the form.
The filters don't work with form.data.game_date because it's a raw string. They should work with form.cleaned_data.game_date, which has been converted to a python date object.
Finally, you haven't implemented anything in your done method, you've just copied the comment from the docs. You could create a new game using cleaned_data as follows:
def done(self, request, cleaned_data):
game = Game.objects.create(**cleaned_data)
return HttpResponseRedirect('/games/success')

Saving data using Django ModelForms

I used this code previously it worked fine and i was suggested to use ModelForm by another member, it did make sense to use the form.is_valid() function etc.. so thought of giving it a try.
I went through some other examples on the internet but mine does not seem to work for some reason, or may be I am not doing it right, I get the following when I print the form in the view, and it goes to the else statement, so my form does not get saved
<input id="id_product" type="text" name="product" value="aassddf" maxlength="250" />
FAIL
My model.py
from django.db import models
from django.forms import ModelForm
class Category(models.Model):
name = models.CharField(max_length=250)
def __unicode__(self):
return self.name
class Product(models.Model):
category = models.ForeignKey(Category)
product = models.CharField(max_length=250)
quantity = models.IntegerField(default=0)
price = models.FloatField(default=0.0)
def __unicode__(self):
return self.product
class ProductForm(ModelForm):
class Meta:
model = Product
My views.py
from models import *
from django.shortcuts import render_to_response
from django.http import HttpResponseRedirect
def index(request):
...
...
def add_product(request):
if request.method == 'POST':
form = ProductForm(request.POST)
print form['product']
if form.is_valid():
form.save()
return HttpResponseRedirect('/product')
else:
print 'FAIL'
return HttpResponseRedirect('/product')
My html
<form method="post" action="add_product/">
{% csrf_token %}
<label for="category">Category</label>
<select name="category" id="category">
{% for category in category_list %}
<option> {{ category.name }} </option>
{% endfor %}
</select>
<label for="product">Product</label>
<input type="text" name="product" id="product">
<label for="quantity">Quantitiy</label>
<input type="text" name="quantity" id="quantity">
<label for="price">Price</label>
<input type="text" name="price" id="price">
<input type="submit" value="Add New product" id="create">
</form>
Is there a better way i could save the data, using ModelForms ??
Thanks in advance for the help.
You should read the documentation. If the form is not valid, it will have a whole set of errors associated with it, which will tell you exactly why. But you just throw that away, and redirect to /product. The docs show exactly how to redisplay the form with the errors.
Also you should not write HTML form field tags directly in your template: use the form object from the view - {{ form.product }}, etc - as these will be repopulated with the appropriate values on redisplay.
Thanks to Daniel Roseman and Anuj Gupta I think I finally re-worked on my code on got it working in a standard way so it will generate the html form and validate errors.
So for anyone else who is trying to work django forms here is the code I worked on.
My model.py is was almost the same one i posted on the question but i removed
class ProductForm(ModelForm):
class Meta:
model = Product
I created a new form.py here is the code-
from django import forms
from models import Category
class ProductForm(forms.Form):
# Put all my Categories into a select option
category = forms.ModelChoiceField(queryset=Category.objects.all())
product = forms.CharField()
quantity = forms.IntegerField()
price = forms.FloatField()
My views.py changed had a lot of changes -
def add_product(request):
success = False
if request.method == "POST":
product_form = ProductForm(request.POST)
if product_form.is_valid():
success = True
category = Category.objects.get(name=product_form.cleaned_data['category'])
product = product_form.cleaned_data['product']
quantity = product_form.cleaned_data['quantity']
price = product_form.cleaned_data['price']
new_product = Product(category = category, product = product, quantity = quantity, price = price )
new_product.save()
new_product_form = ProductForm()
ctx2 = {'success':success, 'product_form':new_product_form}
return render_to_response('product/add_product.html', ctx2 , context_instance=RequestContext(request))
else:
product_form = ProductForm()
ctx = {'product_form':product_form}
return render_to_response('product/add_product.html', ctx , context_instance=RequestContext(request))
Finally in my html page i used {{ product_form.as_p }} so it created the forms dynamically
{% if success %}
<h3> product added successfully </h3>
{% endif %}
<form method="post" action=".">
{% csrf_token %}
{{ product_form.as_p }}
<input type="submit" value="Add New product" id="create">
<input type="reset" value="reset" id="reset">
</form>
This may not be the perfect solution, but for a starter like me this sounds good, and at times you just get lost while reading the docs lol, hope it helps some one.
Cheers
Try:
<form method="post" action="add_product/">
{% csrf_token %}
{{ form.as_p }}
</form>
in your template, instead of hand-coding the form's input tags. This shortcut will generate the form html for you, as well as print validation errors.
Make sure you return the form object to the template when:
There is no request.POST (form has not been submitted)
form.is_valid() fails (form has validation errors)
Of course, this is only to get you started. You really should read the docs

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