Allow viewing history of deleted elements

logs/models.py

@@ -291,18 +291,19 @@ class History:
         self._last_version = None
         self.event_type = HistoryEvent
 
-    def get(self, instance):
+    def get(self, instance_id, model):
         """
-        :param interface: The instance to lookup
+        :param instance_id: int, The id of the instance to lookup
+        :param model: class, The type of object to lookup
         :return: list or None, a list of HistoryEvent, in reverse chronological order
         """
         self.events = []
 
-        # Get all the versions for this interface, with the oldest first
+        # Get all the versions for this instance, with the oldest first
         self._last_version = None
         interface_versions = filter(
-            lambda x: x.field_dict["id"] == instance.id,
-            Version.objects.get_for_model(type(instance)).order_by("revision__date_created")
+            lambda x: x.field_dict["id"] == instance_id,
+            Version.objects.get_for_model(model).order_by("revision__date_created")
         )
 
         for version in interface_versions:
@@ -346,16 +347,6 @@ class History:
 
 
 class UserHistoryEvent(HistoryEvent):
-    def __init__(self, user, version, previous_version=None, edited_fields=None):
-        """
-        :param user: User, The user who's history is being built
-        :param version: Version, the version of the user for this event
-        :param previous_version: Version, the version of the user before this event
-        :param edited_fields: list, The list of modified fields by this event
-        """
-        super(UserHistoryEvent, self).__init__(version, previous_version, edited_fields)
-        self.user = user
-
     def _repr(self, name, value):
         """
         Returns the best representation of the given field
@@ -425,7 +416,6 @@ class UserHistoryEvent(HistoryEvent):
 
     def __eq__(self, other):
         return (
-            self.user.id == other.user.id
             and self.edited_fields == other.edited_fields
             and self.date == other.date
             and self.performed_by == other.performed_by
@@ -433,13 +423,12 @@ class UserHistoryEvent(HistoryEvent):
         )
 
     def __hash__(self):
-        return hash((self.user.id, frozenset(self.edited_fields), self.date, self.performed_by, self.comment))
+        return hash((frozenset(self.edited_fields), self.date, self.performed_by, self.comment))
 
     def __repr__(self):
-        return "{} edited fields {} of {} ({})".format(
+        return "{} edited fields {} ({})".format(
             self.performed_by,
             self.edited_fields or "nothing",
-            self.user,
             self.comment or "No comment"
         )
 
@@ -449,23 +438,23 @@ class UserHistory(History):
         super(UserHistory, self).__init__()
         self.event_type = UserHistoryEvent
 
-    def get(self, user):
+    def get(self, user_id):
         """
-        :param user: User, the user to lookup
+        :param user_id: int, the id of the user to lookup
         :return: list or None, a list of UserHistoryEvent, in reverse chronological order
         """
         self.events = []
 
         # Find whether this is a Club or an Adherent
         try:
-            obj = Adherent.objects.get(user_ptr_id=user.id)
+            obj = Adherent.objects.get(user_ptr_id=user_id)
         except Adherent.DoesNotExist:
-            obj = Club.objects.get(user_ptr_id=user.id)
+            obj = Club.objects.get(user_ptr_id=user_id)
 
         # Add as "related" histories the list of Machine objects
         # that were once owned by this user
         self.related = filter(
-            lambda x: x.field_dict["user_id"] == user.id,
+            lambda x: x.field_dict["user_id"] == user_id,
             Version.objects.get_for_model(Machine).order_by("revision__date_created")
         )
         self.related = [RelatedHistory(
@@ -477,7 +466,7 @@ class UserHistory(History):
         # Get all the versions for this user, with the oldest first
         self._last_version = None
         user_versions = filter(
-            lambda x: x.field_dict["id"] == user.id,
+            lambda x: x.field_dict["id"] == user_id,
             Version.objects.get_for_model(User).order_by("revision__date_created")
         )
 
@@ -548,11 +537,11 @@ class MachineHistory(History):
         super(MachineHistory, self).__init__()
         self.event_type = MachineHistoryEvent
 
-    def get(self, machine):
+    def get(self, machine_id):
         # Add as "related" histories the list of Interface objects
         # that were once assigned to this machine
         self.related = list(filter(
-            lambda x: x.field_dict["machine_id"] == machine.id,
+            lambda x: x.field_dict["machine_id"] == machine_id,
             Version.objects.get_for_model(Interface).order_by("revision__date_created")
         ))
 
@@ -563,7 +552,7 @@ class MachineHistory(History):
             i.field_dict["id"]) for i in self.related]
         self.related = list(dict.fromkeys(self.related))
 
-        return super(MachineHistory, self).get(machine)
+        return super(MachineHistory, self).get(machine_id, Machine)
 
 
 class InterfaceHistoryEvent(HistoryEvent):
@@ -607,3 +596,6 @@ class InterfaceHistory(History):
     def __init__(self):
         super(InterfaceHistory, self).__init__()
         self.event_type = InterfaceHistoryEvent
+
+    def get(self, interface_id):
+        return super(InterfaceHistory, self).get(machine_id, Interface)

logs/views.py

@@ -514,22 +514,44 @@ def stats_search_machine_history(request):
     return render(request, "logs/search_machine_history.html", {"history_form": history_form})
 
 
-def get_history_object(request, model, object_name, object_id):
+def get_history_object(request, model, object_name, object_id, allow_deleted=False):
     """Get the objet of type model with the given object_id
     Handles permissions and DoesNotExist errors
     """
+    instance = None
+    is_deleted = False
+
     try:
         object_name_id = object_name + "id"
         kwargs = {object_name_id: object_id}
         instance = model.get_instance(**kwargs)
     except model.DoesNotExist:
+        pass
+
+    if instance is None and allow_deleted:
+        # Try to find an instance among the Version objects
+        is_deleted = True
+        versions = filter(
+            lambda x: x.field_dict["id"] == object_id,
+            Version.objects.get_for_model(model)
+        )
+        versions = list(versions)
+        if len(versions):
+            instance = versions[0]
+
+    if instance is None:
         messages.error(request, _("Nonexistent entry."))
         return False, redirect(
             reverse("users:profil", kwargs={"userid": str(request.user.id)})
         )
 
-    can, msg, _permissions = instance.can_view(request.user)
-    if not can:
+    if is_deleted:
+        can_view = can_view_app("logs")
+        msg = None
+    else:
+        can_view, msg, _permissions = instance.can_view(request.user)
+
+    if not can_view:
         messages.error(
             request, msg or _("You don't have the right to access this menu.")
         )
@@ -559,7 +581,7 @@ def detailed_history(request, object_name, object_id):
         raise Http404(_("No model found."))
 
     # Get instance and check permissions
-    can_view, instance = get_history_object(request, model, object_name, object_id)
+    can_view, instance = get_history_object(request, model, object_name, object_id, allow_deleted=True)
     if not can_view:
         return instance
 
@@ -567,7 +589,7 @@ def detailed_history(request, object_name, object_id):
     max_result = GeneralOption.get_cached_value("pagination_number")
     events = re2o_paginator(
         request,
-        history.get(instance),
+        history.get(object_id),
         max_result
     )