New Written Django Manager is not working in the template

Question

I have a simple todolist app where each task has a Booleanfield called is_deleted. in my list template, I only want to show the tasks with is_deleted=False .

I know I can use Task.objects.all().filter(is_deleted=False) in my view; but I want to do it with managers in my template. here is my manager:

    class TaskManager(models.Manager):
        def available(self):
            return self.filter(is_deleted=False)
              .
              .
     objects = TaskManager()

here is my view:

class TaskList(ListView):
    model = models.Task
    context_object_name="tasks"
    template_name = "home/list.html"
    paginate_by=5  

and here is the the condition in my template:

 {% if tasks.available%} ...

Answer 1

My answer is a complement / a correction of your work :

• Your manager is ok

• But you need to specify in the Task model that you override the default manager by the your custom manager like this :

    Class Task(models.Model):
        # others fields here
  
        # override the default objects manager
        objects = TaskManager()
        # You can also define a new manager and keep the default objects, in the case you will use it later.
        # objects = models.Manager() -> Task.objects.all() give all objects
        # is_available = TaskManager() -> Task.is_available.all() give only nt deleted task.
  

• in your views.py

    class TaskList(ListView):
        model = models.Task
        context_object_name="tasks"
        template_name = "home/list.html"
        paginate_by=5
  
        # If you override the default objects manager with TaskManager
        # Then you are nothing to do, {{ tasks }} is the queryset in the template
  
        # If you defined two managers as recommended above, then you need
        # to override the queryset attribute of the ListView
        queryset = Task.is_available.all()  # Explicit call of custom manager
  

• Anyways in your template, you don't need {% if %} tag to filter results, all your task are available on the context_object_name value name.

    {% for task in tasks %}
    {{ task.name }}
    ...
    {% endfor %}