Django global variable based on user groups - django

Question

In my Django project I have a database that is populated from outside Django, but needs the Django functionality to display data in the database in a user friendly manner. The legacy database structure is as follows:
class SomeModel(models.Model):
#some fields
group_access = models.ForeignKey(AccessGroup,on_delete=models.CASCADE()
class AccessGroup(models.Model):
group_name = models.CharField(max_length=200)
The users have a custom User profile with manytomany relationship with group names assigned to the specific user:
class CustomUser(models.Model):
#some values
projects = models.ManyToManyField(AccessGroup)
Currently I am able to display data from all groups a user has access to, but what I am looking for is a way to create a drop down menu so that users can switch between groups without the need to log out or reenter group on every view.

Answer 1

You could try something like this:
AccessGroup.objects.filter(CustomUser__pk=1)
Or
CustomUser.objects.filter(AccessGroup__group_name='GropName')
https://docs.djangoproject.com/en/2.0/topics/db/examples/many_to_many/

Answer 2

you can extend the django user model, somthing like
from django.contrib.auth.models import User
class CustomUser(models.Model):
projects = models.ManyToManyField(AccessGroup)
class UserProfile(models.Model):
user = models.OneToOneField(User, unique=True)
custom_user = models.ForeignKey(CustomUser, unique=False)
class SomeModel(models.Model):
#some fields
group_access = models.ForeignKey(AccessGroup,on_delete=models.CASCADE()
class AccessGroup(models.Model):
group_name = models.CharField(max_length=200)
then something like this to get the data in your view
def index(request):
AccessGroup.objects.filter(user__id=persion(request.user).id)

Answer 3

I'll assume you know how to get the list of groups, and are just looking as to how to get this list into templates. If not, let me know and I'll explain that as well.
If you're trying to get a global variable into templates, there are really 3 main options:
Make a custom template tag that takes the current user as input, and generates this list as output.
Use Middleware to generate the list, and append it to the current context for each request
Use a method on your user class, or a mixin of it (really easy if you use a custom user class), and just call that method as user.method in your templates. Remember to exclude parentheses from the method call (only in templates), and keep in mind that this method shouldn't accept any parameters other than self.

Answer 4

Thank you everybody for getting me on the right track. What I ended up doing is writing a context processor for checking the user permissions:
#context_processors.py
def check_groups(request):
group_check = AccessGroup.objects.values('id','group_name').filter(projects=request.user.id)
return {
'group_check': group_check,
}
Afterwards I created a Bootstrap-select dropdown in my base.html
<select class="selecpicker">
<optgroup>
<option data-hidden="true">Choose group</option>
{% for grpup in group_check %}
<option val="group.id">{{ group.group_name }}</option>
{% endfor %}
</optgroup>
And the it is just a matter of users using it as means to switch access groups in views and passing the value via ajax to any other template views I come across.
Not the 100% what I was looking for, but it works and my users are happy.