Handling one to one relationship between django models - django

Question

I am having a one to one relationship between 2 models. While creating the second model, I want to pass the instance of the first model to the second one.
These 2 models are new tabs/features in our web application. I tried passing the instance through URL but didn't succeed. Maybe I am not following steps correctly.
Details about:
python version: Python 3.6.4 :: Anaconda, Inc.
django version: 2.0.2-3
Please find below the code:
1) models.py
class StudyConcept(models.Model):
requestor_name = models.CharField(max_length=240, blank=False, null=False)
project = models.CharField(max_length=240, blank=False, null=False)
date_of_request = models.DateField(blank=False, null=False)
brief_summary = models.CharField(max_length=4000, blank=False, null=False)
user = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
return str(self.id)
class Logistics(models.Model):
budget = models.CharField(max_length=255, blank=False, null=False)
business_technology = models.CharField(max_length=3, choices=CHOICES, blank=False, null=False)
vendor_or_contracts = models.CharField(max_length=3, choices=CHOICES, blank=False, null=False)
studyConcept = models.OneToOneField(StudyConcept, on_delete = models.CASCADE)
user = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
return str(self.id)
def get_absolute_url(self):
return reverse('update_Logistics', kwargs={'pk': self.pk})
def get_deliverablesLogistics(self):
return ','.join([str(i) for i in self.deliverablesLogistics.all().values_list('id', flat=True)])
def get_paymentScheduleLogistics(self):
return ','.join([str(i) for i in self.paymentScheduleLogistics.all().values_list('id', flat=True)])
def get_commentsLogistics(self):
return ','.join([str(i) for i in self.commentsLogistics.all().values_list('id', flat=True)])
class DeliverablesLogistics(models.Model):
milestone_deliverable = models.CharField('MileStone/Deliverable', max_length=480, blank=False, null=False)
poa = models.CharField('POA', max_length=480, blank=False, null=False)
start_date = models.DateField(blank=False, null=False)
end_date = models.DateField(blank=False, null=False)
logistics = models.ForeignKey(Logistics, related_name='deliverablesLogistics', on_delete=models.CASCADE)
def __str__(self):
return str(self.id)
class PaymentScheduleLogistics(models.Model):
milestone_deliverable = models.CharField('MileStone/Deliverable', max_length=480, blank=False, null=False)
cost = models.DecimalField(max_digits=14, decimal_places=2, blank=False, null=False, default=0)
estimated_payment_date = models.DateField(blank=False, null=False)
logistics = models.ForeignKey(Logistics, related_name='paymentScheduleLogistics', on_delete=models.CASCADE)
def __str__(self):
return str(self.id)
class CommentsLogistics(models.Model):
comments = models.CharField('Comment', max_length=2000, blank=True, null=True)
commented_by = models.CharField(max_length=2000, blank=True, null=True)
logistics = models.ForeignKey(Logistics, related_name='commentsLogistics', on_delete=models.CASCADE)
def __str__(self):
return str(self.id)
views.py
def load_concepts(request):
currentUser = User.objects.get(id=request.user.id)
concepts = StudyConcept.objects.all().filter(user=request.user)
#concepts = get_object_or_404(StudyConcept)
return render(request, 'concept_dropdown_list_options.html',{
'concepts':concepts
})
class LogisticsFormsetCreate(CreateView):
model = Logistics
template_name = 'createLogistics.html'
form_class = LogisticsForm
success_url = reverse_lazy('create_Logistics')
def get_context_data(self, **kwargs):
data = super(LogisticsFormsetCreate, self).get_context_data(**kwargs)
if self.request.POST:
data['deliverable'] = DeliverablesLogisticsFormset(self.request.POST, prefix='deliverables')
data['paymentSchedule'] = PaymentScheduleLogisticsFormset(self.request.POST, prefix='payments')
data['comment'] = CommentsLogisticsFormset(self.request.POST, prefix='comments')
#data['studyRequestConcept'] = self.request.POST.get('studyRequestConcept')
else:
data['deliverable'] = DeliverablesLogisticsFormset(prefix='deliverables')
data['paymentSchedule'] = PaymentScheduleLogisticsFormset(prefix='payments')
data['comment'] = CommentsLogisticsFormset(prefix='comments')
#data['studyRequestConcept'] = self.request.GET.get('studyRequestConcept')
return data
def form_valid(self, form):
context = self.get_context_data()
deliverable = context['deliverable']
paymentSchedule = context['paymentSchedule']
comment = context['comment']
with transaction.atomic():
if deliverable.is_valid() and paymentSchedule.is_valid() and comment.is_valid():
self.object = form.save(commit=False)
self.object.user = self.request.user
self.object = form.save()
deliverable.instance = self.object
deliverable.save()
paymentSchedule.instance = self.object
paymentSchedule.save()
comment.instance = self.object
comment.save()
messages.success(self.request, Logistics.__name__ +' Form ID: '+ str(self.object.id) + ' was submitted successfully')
return super(LogisticsFormsetCreate, self).form_valid(form)
else:
return self.render_to_response(self.get_context_data(form=form))
Template
{% extends "header.html" %}
{% load widget_tweaks %}
{% block content %}
{% csrf_token %}
{% include 'xdsoft_stylesheets.html' %}
{% include 'messages.html' %}
<div class="container" align="center">
<h1 class="display-5">Logistics</h1>
</div>
<br/>
<div class="table-responsive">
<table class="table table-striped table-bordered" id="example" data-toggle="table"
data-filter-control="true" data-show-export="true"
data-click-to-select="true" data-toolbar="#toolbar" data-escape>
<thead>
<tr>
<th></th>
<th class="text-center" data-field="id" data-filter-control="input">ID</th>
<th class="text-center" data-field="project" data-filter-control="input">Project</th>
<th class="text-center" data-field="date_of_request" data-filter-control="input">Date</th>
<th class="text-center" data-field="brief_summary" data-filter-control="input">Summary</th>
<th class="text-center" data-field="scientific_question" data-filter-control="input">Question</th>
</tr>
</thead>
<tbody>
{%for studyRequestConcept in concepts %}
<tr>
<td style="width:200px">
<a class=" btn btn-primary js-create-logistics" data-toggle="modal" data-target="#modal" href="{% url 'create_Logistics' %}">
<span class="glyphicon glyphicon-plus"></span>
New Logistics
</a>
</td>
<td class="text-left">{{studyRequestConcept.id}}</td>
<td class="text-left">{{studyRequestConcept.project}}</td>
<td class="text-left">{{studyRequestConcept.date_of_request}}</td>
<td class="text-left">{{studyRequestConcept.brief_summary}}</td>
<td class="text-left">{{studyRequestConcept.scientific_question}}</td>
</tr>
{% endfor%}
</tbody>
</table>
</div>
{% comment %}The modal container{% endcomment %}
<div class="modal" id="modal" data-backdrop="false"></div>
<script>
$(function () {
$('.js-create-logistics').click( function () {
var btn = $(this)
$.ajax({
url: btn.attr("href"),
context: document.body
}).done(function(response) {
$("#modal").html(response);
});
});
});
</script>
{% endblock %}
I have a view/template where I list all the Study Concepts and every row has a create new Logistics button next to it. After clicking create new logistics button, the modal/view will open that will allow you to create a new Logistics. I want to pass the instance of the object study concept when I click the button.
Also, CreateLogistics is a class-based view designed using "from django.views.generic import CreateView"
I will be more than happy to provide any further code or information needed. Thanks in advance for all the support and help.
Regards,
Amey Kelekar

Answer 1

You haven't shown your URLs, but you need to accept the ID in the URL for the CreateView and use it in form_valid. For example:
path('/create_logistics/<int:id>/', LogisticsFormsetCreate.as_view(), name="create_Logistics"),
So in the template you would do:
<a class="btn btn-primary js-create-logistics" data-toggle="modal" data-target="#modal" href="{% url 'create_Logistics' id=studyRequestConcept.id %}">
and in the view:
def form_valid(self, form):
...
self.object = form.save(commit=False)
self.object.user = self.request.user
self.object.studyConcept_id = self.kwargs['id']
self.object.save()
...