'Nonetype' Object has no attribute 'groups'

Question

I’m using a function in mine Templatetagsdjango that basically checks if the user is in the group that has the permission for the given button.

The return 'True or False' works well, IE, it shows the button if the user is in the group, but when trying to open the button, I have the following error in the console AttributeError: 'NoneType' object has no attribute 'groups' . I don’t know if it has anything to do with being a modal that would have to be opened after clicking the button, because another button that has a function of just sending an email and does not change the screen user, works without errors. I did not find on the internet anything like my problem, I appreciate any light.

My Function

@register.filter
def group_permission(user, grupo):
if user.groups.filter(name=grupo):
    return True

return False

My Template

<nav class="navbar navbar-expand-sm bg-dark navbar-dark sticky-top">
        {% if user|group_permission:'GERENCIA' %}
        <a class="btn btn-success dt-create" data-url="{% url 'inventario_create' %}">Adicionar</a>

        {% endif %}
    </nav>

My View

@login_required
def inventario_create(request):
if request.method == 'POST':
    print('entrou no POST do create')
    form = InventarioForm(request.POST)
else:
    form = InventarioForm()
return save_insert(request, form, 'inventario_create.html')

This is my JS calling the Modal

var ShowForm = function(){
		var btn = $(this);
		$.ajax({
			url: btn.attr("data-url"),
			type: 'get',
			dataType:'json',
			beforeSend: function(data){
                waitingDialog.show('Carregando Inventários', {dialogSize: 'sm', progressType: 'success'})
			},
			success: function(data){
			    waitingDialog.hide();
			   	$('#myModal .modal-content').html(data.html_form);
			   	$('#myModal').modal('show')
			},
			 error: function (error) {
                    console.log(error);
                    alert('error handing here');
              }
		});
	};

**Tracerback do Erro**
Traceback (most recent call last):
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/contrib/auth/decorators.py", line 21, in _wrapped_view
    return view_func(request, *args, **kwargs)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/inventarios/views.py", line 103, in inventario_create
    return save_insert(request, form, 'inventario_create.html')
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/contrib/auth/decorators.py", line 21, in _wrapped_view
    return view_func(request, *args, **kwargs)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/inventarios/views.py", line 123, in save_insert
    data['inventario_list'] = render_to_string('inventario_list.html')
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/loader.py", line 62, in render_to_string
    return template.render(context, request)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 171, in render
    return self._render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 937, in render
    bit = node.render_annotated(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 904, in render_annotated
    return self.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/loader_tags.py", line 150, in render
    return compiled_parent._render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 937, in render
    bit = node.render_annotated(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 904, in render_annotated
    return self.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/loader_tags.py", line 62, in render
    result = block.nodelist.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 937, in render
    bit = node.render_annotated(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 904, in render_annotated
    return self.render(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/defaulttags.py", line 302, in render
    match = condition.eval(context)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/defaulttags.py", line 876, in eval
    return self.value.resolve(context, ignore_failures=True)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/venv/lib/python3.7/site-packages/django/template/base.py", line 698, in resolve
    new_obj = func(obj, *arg_vals)
  File "/Users/rodolfosousa/Documents/GitHub/InventoryPortal/inventarios/templatetags/check_permission.py", line 15, in group_permission
    if user.groups.filter(name=grupo):
AttributeError: 'NoneType' object has no attribute 'groups'

Answer 1

Use this way:

from django import template

register = template.Library() 

@register.filter(name='has_group') 
def has_group(user, group_name):
    return user.groups.filter(name=group_name).exists() 

In your template:

{% if request.user|has_group:"GERENCIA" %} 
    <p>Usuário pertente ao grupo
{% else %}
    <p>Ususário não pertence ao grupo</p>
{% endif %}