Nested Loops in Django - django

Question

I have in my models Projects and Tasks. I'd like to display on the template:
Project 1
Task 1:1
Task 1:2
Task 1:n
Project 2
Task 2:1
Task 2:n
Project n
Here's the model
class Projects(models.Model):
slug_project = models.CharField(max_length=200)
project_name = models.CharField(max_length=200)
project_due_date = models.DateTimeField()
project_lead_time = models.IntegerField()
project_assignee = models.CharField(max_length=200)
project_status = models.CharField(max_length=200)
def __str__(self):
return self.project_name
class Tasks(models.Model):
slug_task = models.CharField(max_length=200)
task_name = models.CharField(max_length=200)
task_desc = models.TextField(null=True)
task_channel = models.CharField(max_length=200)
task_id = models.ForeignKey(Projects, on_delete=models.CASCADE)
task_due_date = models.DateTimeField('Due Date')
task_lead_time = models.IntegerField()
task_assignee = models.CharField(max_length=200)
def __str__(self):
return self.task_name
I'm not sure how to construct the view properly but here's my code:
class somePage(generic.ListView):
template_name = 'dashboard/index.html'
context_object_name = 'project_object'
def get_queryset(self):
"""Return the last five published Coupons."""
return Projects.objects.order_by('project_name')
def get_context_data(self, **kwargs):
context = super(somePage, self).get_context_data(**kwargs)
# context['tasks'] = Tasks.objects.order_by('task_name') #this would display ALL tasks
context.update({
'all_project': Projects.objects.all(),
'all_tasks': Tasks.objects.filter(task__id=self.object),
})
return context
And I'm also not confident how construct the template:
{% if project_object %}
{% for project_name in project_object %}
<div class="card_row_h1">
<a href="{% url 'dashboard:task_list' project_name.id %}">
{{ project_name }}
</a>
</div>
{% if all_tasks %}
{% for task_name in tasks %}
<div class="card_row_h2" style="width: 100%; padding-left: 30px;">
<small>{{ task_name }}</small>
</div>
{% endfor %}
{% else %}
<div class="card_row_h2" style="width: 100%;">
No Tasks for This Project
</div>
{% endif %}
{% endfor %}
The result is that the Projects display correctly, but under each project I get nothing for 'all_tasks' and it displays 'No tasks for this project' or if I use 'tasks' (see commented line in view), it displays all tasks for all the projects over and over.
So there are two questions here:
how do I construct the view, and
how do I construct the template?
I'm a newbie but I've been stuck on this for over a day. Thanks in advance.

Answer 1

Good start! I think you can simplify this a little. You can get the set of tasks for a project using the reverse look up for foreign keys. Without setting the related_name argument in the task models ForeignKey, you can access the tasks associated to a project using some_project.task_set.all(). You can even do this in the template so you dont need to worry about overriding the context data for the view:
views.py
class MainPage(ListView):
template_name = 'dashboard/index.html'
context_object_name = 'projects'
def get_queryset(self):
return Projects.objects.order_by('project_name')
index.html
{% for project in projects %}
<div class="card_row_h1">
<a href="{% url 'dashboard:task_list' project.id %}">
{{ project.project_name }}
</a>
</div>
{% if project.task_set.all %}
{% for task in project.task_set.all %}
<div class="card_row_h2" style="width: 100%; padding-left: 30px;">
<small>{{ task.task_name }}</small>
{% endfor %}
{% else %}
<div class="card_row_h2" style="width: 100%;">
No Tasks for This Project
</div>
{% endif %}
{% endfor %}
If you wanted, in your Tasks model, you could change
task_id = models.ForeignKey(Projects, on_delete=models.CASCADE)
to project = models.ForeignKey(Projects, on_delete=models.CASCADE, related_name="tasks"
This would make the field name a little more intuitive, and also let you access the Tasks for a project just by doing:
my_project_instance.tasks.all()