Add CRUD and form helpers

core/forms.py

@@ -1,9 +1,41 @@
 from django import forms
 from django.contrib.auth.forms import UserCreationForm
+from django.core.exceptions import FieldDoesNotExist
 
 from .models import User
 
+# from django.forms import ModelForm
+
+
 # Create your forms here.
+class RestrictedFormMixin:
+    """
+    This mixin is used to restrict the queryset of a form to the current user.
+    The request object is passed from the view.
+    Fieldargs is used to pass additional arguments to the queryset filter.
+    """
+
+    fieldargs = {}
+
+    def __init__(self, *args, **kwargs):
+        # self.fieldargs = {}
+        self.request = kwargs.pop("request")
+        super().__init__(*args, **kwargs)
+        for field in self.fields:
+            # Check it's not something like a CharField which has no queryset
+            if not hasattr(self.fields[field], "queryset"):
+                continue
+
+            model = self.fields[field].queryset.model
+            # Check if the model has a user field
+            try:
+                model._meta.get_field("user")
+                # Add the user to the queryset filters
+                self.fields[field].queryset = model.objects.filter(
+                    user=self.request.user, **self.fieldargs.get(field, {})
+                )
+            except FieldDoesNotExist:
+                pass
 
 
 class NewUserForm(UserCreationForm):