From caa7347fabd20763ece2ce6b3dee4b92fa6e612a Mon Sep 17 00:00:00 2001
From: Griatch <griatch@gmail.com>
Date: Mon, 28 Nov 2022 21:40:20 +0100
Subject: [PATCH] Add AT_EXIT_TRAVERSE signal. Resolve #2687

---
 CHANGELOG.md                      |  1 +
 docs/source/Components/Signals.md |  1 +
 evennia/objects/objects.py        |  2 ++
 evennia/server/signals.py         | 22 ++++++++++------------
 4 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 28e672077f..b994358757 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -219,6 +219,7 @@ Increase requirements: Django 4.1+, Twisted 22.10+ Python 3.9, 3.10, 3.11.  Post
   the given left indent but crops/fills to the width. Used in EvCells.
 - `EvTable` now supports passing `EvColumn`s as a list directly, (`EvTable(table=[colA,colB])`)
 - Add `tags=` search criterion to `DefaultObject.search`.
+- Add `AT_EXIT_TRAVERSE` signal, firing when an exit is traversed.
 
 ## Evennia 0.9.5
 
diff --git a/docs/source/Components/Signals.md b/docs/source/Components/Signals.md
index 19de67b3dc..1d458e862d 100644
--- a/docs/source/Components/Signals.md
+++ b/docs/source/Components/Signals.md
@@ -93,6 +93,7 @@ Extra
 - `SIGNAL_SCRIPT_POST_CREATE` - fires when a script is first created, after any hooks.
 - `SIGNAL_CHANNEL_POST_CREATE` - fires when a Channel is first created, after any hooks.
 - `SIGNAL_HELPENTRY_POST_CREATE` - fires when a help entry is first created.
+- `SIGNAL_EXIT_TRAVERSED` - fires when an exit is traversed, just after `at_traverse` hook. The `sender` is the exit itself, `traverser=` keyword hold the one traversing the exit.
 
 The `evennia.signals` module also gives you conveneient access to the default Django signals (these
 use a
diff --git a/evennia/objects/objects.py b/evennia/objects/objects.py
index f23393a44c..ff13c5469f 100644
--- a/evennia/objects/objects.py
+++ b/evennia/objects/objects.py
@@ -18,6 +18,7 @@ from evennia.commands.cmdsethandler import CmdSetHandler
 from evennia.objects.manager import ObjectManager
 from evennia.objects.models import ObjectDB
 from evennia.scripts.scripthandler import ScriptHandler
+from evennia.server.signals import SIGNAL_EXIT_TRAVERSED
 from evennia.typeclasses.attributes import ModelAttributeBackend, NickHandler
 from evennia.typeclasses.models import TypeclassBase
 from evennia.utils import ansi, create, funcparser, logger, search
@@ -2886,6 +2887,7 @@ class ExitCommand(_COMMAND_DEFAULT_CLASS):
         if self.obj.access(self.caller, "traverse"):
             # we may traverse the exit.
             self.obj.at_traverse(self.caller, self.obj.destination)
+            SIGNAL_EXIT_TRAVERSED.send(sender=self.obj, traverser=self.caller)
         else:
             # exit is locked
             if self.obj.db.err_traverse:
diff --git a/evennia/server/signals.py b/evennia/server/signals.py
index 499e82418d..2fcc4b6d67 100644
--- a/evennia/server/signals.py
+++ b/evennia/server/signals.py
@@ -87,13 +87,17 @@ SIGNAL_HELPENTRY_POST_CREATE = Signal()
 # first created, after all hooks.
 SIGNAL_CHANNEL_POST_CREATE = Signal()
 
+# The sender is the exit used when traversing, as well as 'traverser', for the one traversing
+# Called just after at_traverse hook.
+SIGNAL_EXIT_TRAVERSED = Signal()
+
 # Django default signals (https://docs.djangoproject.com/en/2.2/topics/signals/)
 
 from django.core.signals import request_finished  # "             ends.
 from django.core.signals import request_started  # Sent when HTTP request begins.
-from django.db.backends.signals import (  # Sent when making initial connection to database
+from django.db.backends.signals import (
     connection_created,
-)
+)  # Sent when making initial connection to database
 from django.db.models.signals import m2m_changed  # Sent when a ManyToManyField changes.
 from django.db.models.signals import post_delete  # after         "
 from django.db.models.signals import post_init  # end
@@ -101,15 +105,9 @@ from django.db.models.signals import post_migrate  # after     "
 from django.db.models.signals import post_save  # after            "
 from django.db.models.signals import pre_delete  # Sent before an object is deleted.
 from django.db.models.signals import pre_migrate  # Sent before migration starts
+from django.db.models.signals import pre_save  # Sent before a typeclass' .save is called.
 from django.db.models.signals import (
-    pre_save,  # Sent before a typeclass' .save is called.
-)
-from django.db.models.signals import (  # Sent at start of typeclass __init__ (before at_init)
     pre_init,
-)
-from django.test.signals import (
-    setting_changed,  # Sent when setting changes from override
-)
-from django.test.signals import (
-    template_rendered,  # Sent when test system renders template
-)
+)  # Sent at start of typeclass __init__ (before at_init)
+from django.test.signals import setting_changed  # Sent when setting changes from override
+from django.test.signals import template_rendered  # Sent when test system renders template