Added history view

constance/admin.py

@@ -41,6 +41,14 @@ class ConstanceAdmin(admin.ModelAdmin):
         return [
             path("", self.admin_site.admin_view(self.changelist_view), name=f"{info}_changelist"),
             path("", self.admin_site.admin_view(self.changelist_view), name=f"{info}_add"),
+            # Redirect <object_id>/change/ to the changelist so that "Recent actions" links in the admin index point
+            # somewhere useful.
+            path(
+                "<path:object_id>/change/",
+                lambda request, object_id: HttpResponseRedirect("../../"),
+                name=f"{info}_change",
+            ),
+            path("history/", self.admin_site.admin_view(self.history_view), name=f"{info}_history"),
         ]
 
     def get_config_value(self, name, options, form, initial):
@@ -160,6 +168,47 @@ class ConstanceAdmin(admin.ModelAdmin):
         request.current_app = self.admin_site.name
         return TemplateResponse(request, self.change_list_template, context)
 
+    def history_view(self, request, object_id=None, extra_context=None):
+        """Display the change history for constance config values."""
+        from django.contrib.admin.views.main import PAGE_VAR
+
+        if not self.has_view_or_change_permission(request):
+            raise PermissionDenied
+
+        ct = ContentType.objects.get_for_model(self.model)
+        action_list = (
+            LogEntry.objects.filter(
+                content_type=ct,
+                object_id="Config",
+            )
+            .select_related()
+            .order_by("-action_time")
+        )
+
+        paginator = self.get_paginator(request, action_list, 100)
+        page_number = request.GET.get(PAGE_VAR, 1)
+        page_obj = paginator.get_page(page_number)
+        page_range = paginator.get_elided_page_range(page_obj.number)
+
+        context = {
+            **self.admin_site.each_context(request),
+            "title": _("Change history: %s") % self.model._meta.verbose_name_plural.capitalize(),
+            "action_list": page_obj,
+            "page_range": page_range,
+            "page_var": PAGE_VAR,
+            "pagination_required": paginator.count > 100,
+            "opts": self.model._meta,
+            "app_label": "constance",
+            **(extra_context or {}),
+        }
+
+        request.current_app = self.admin_site.name
+        return TemplateResponse(
+            request,
+            "admin/constance/config_history.html",
+            context,
+        )
+
     def _log_config_change(self, request, changed_fields):
         """
         Create a Django admin LogEntry recording which config fields were changed.

constance/templates/admin/constance/change_list.html

@@ -23,6 +23,9 @@
 {% block bodyclass %}{{ block.super }} change-list{% endblock %}
 
 {% block content %}
+  <ul class="object-tools">
+    <li><a href="history/" class="historylink">{% trans 'History' %}</a></li>
+  </ul>
   <div id="content-main" class="constance">
     <div class="module" id="changelist">
         <form id="changelist-form" action="" method="post" enctype="multipart/form-data">{% csrf_token %}

constance/templates/admin/constance/config_history.html

@@ -0,0 +1,55 @@
+{% extends "admin/base_site.html" %}
+{% load i18n %}
+
+{% block breadcrumbs %}
+<div class="breadcrumbs">
+  <a href="{% url 'admin:index' %}">{% translate 'Home' %}</a>
+  &rsaquo; <a href="{% url 'admin:app_list' app_label=opts.app_label %}">{{ opts.app_config.verbose_name }}</a>
+  &rsaquo; <a href="{% url 'admin:constance_config_changelist' %}">{{ opts.verbose_name_plural|capfirst }}</a>
+  &rsaquo; {% translate 'History' %}
+</div>
+{% endblock %}
+
+{% block content %}
+<div id="content-main">
+<div id="change-history" class="module">
+
+{% if action_list %}
+    <table>
+        <thead>
+        <tr>
+            <th scope="col">{% translate 'Date/time' %}</th>
+            <th scope="col">{% translate 'User' %}</th>
+            <th scope="col">{% translate 'Action' %}</th>
+        </tr>
+        </thead>
+        <tbody>
+        {% for action in action_list %}
+        <tr>
+            <th scope="row">{{ action.action_time|date:"DATETIME_FORMAT" }}</th>
+            <td>{{ action.user.get_username }}{% if action.user.get_full_name %} ({{ action.user.get_full_name }}){% endif %}</td>
+            <td>{{ action.get_change_message }}</td>
+        </tr>
+        {% endfor %}
+        </tbody>
+    </table>
+    <p class="paginator">
+      {% if pagination_required %}
+        {% for i in page_range %}
+          {% if i == action_list.paginator.ELLIPSIS %}
+            {{ action_list.paginator.ELLIPSIS }}
+          {% elif i == action_list.number %}
+            <span class="this-page">{{ i }}</span>
+          {% else %}
+            <a href="?{{ page_var }}={{ i }}" {% if i == action_list.paginator.num_pages %} class="end" {% endif %}>{{ i }}</a>
+          {% endif %}
+        {% endfor %}
+      {% endif %}
+      {{ action_list.paginator.count }} {% blocktranslate count counter=action_list.paginator.count %}entry{% plural %}entries{% endblocktranslate %}
+    </p>
+{% else %}
+    <p>{% translate "This object doesn't have a change history." %}</p>
+{% endif %}
+</div>
+</div>
+{% endblock %}

tests/test_admin.py

@@ -401,6 +401,78 @@ class TestAdmin(TestCase):
         self.assertIsInstance(response, HttpResponseRedirect)
         self.assertEqual(LogEntry.objects.count(), initial_count)
 
+    def test_history_view(self):
+        """Test that the history view renders and shows LogEntry records."""
+        from django.contrib.admin.models import CHANGE
+        from django.contrib.admin.models import LogEntry
+        from django.contrib.contenttypes.models import ContentType
+
+        ct = ContentType.objects.get_for_model(self.model)
+        LogEntry.objects.create(
+            user_id=self.superuser.pk,
+            content_type_id=ct.pk,
+            object_id="Config",
+            object_repr="Config",
+            action_flag=CHANGE,
+            change_message=json.dumps([{"changed": {"fields": ["INT_VALUE"]}}]),
+        )
+
+        request = self.rf.get("/admin/constance/config/history/")
+        request.user = self.superuser
+        response = self.options.history_view(request)
+        self.assertEqual(response.status_code, 200)
+        response.render()
+        content = response.content.decode()
+        self.assertIn("INT_VALUE", content)
+        self.assertIn("History", content)
+
+    def test_history_view_empty(self):
+        """Test that the history view renders correctly with no entries."""
+        request = self.rf.get("/admin/constance/config/history/")
+        request.user = self.superuser
+        response = self.options.history_view(request)
+        self.assertEqual(response.status_code, 200)
+        response.render()
+        content = response.content.decode()
+        self.assertIn("0", content)
+
+    def test_history_view_permission_denied(self):
+        """Test that the history view denies access to users without permission."""
+        from django.contrib.auth.models import User
+
+        unprivileged = User.objects.create_user("noperm", "noperm", "c@c.cz")
+        request = self.rf.get("/admin/constance/config/history/")
+        request.user = unprivileged
+        with self.assertRaises(PermissionDenied):
+            self.options.history_view(request)
+
+    def test_changelist_has_history_link(self):
+        """Test that the changelist page contains a link to the history view."""
+        request = self.rf.get("/admin/constance/config/")
+        request.user = self.superuser
+        response = self.options.changelist_view(request)
+        response.render()
+        content = response.content.decode()
+        self.assertIn('href="history/"', content)
+        self.assertIn("History", content)
+
+    def test_change_url_redirects_to_changelist(self):
+        """Test that the change URL (used by 'Recent actions') redirects to the changelist."""
+        from django.urls import reverse
+
+        url = reverse("admin:constance_config_change", args=["Config"])
+        self.assertIn("Config/change/", url)
+        request = self.rf.get(url)
+        request.user = self.superuser
+
+        # The change URL is a simple lambda redirect, so invoke it via URL resolution.
+        from django.urls import resolve
+
+        match = resolve(url)
+        response = match.func(request, object_id="Config")
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.url, "../../")
+
     def test_labels(self):
         self.assertEqual(type(self.model._meta.label), str)
         self.assertEqual(type(self.model._meta.label_lower), str)