Add history tracking functionality using django-pghistory; implement views, templates, and middleware for event serialization and context management

history/apps.py

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+from django.apps import AppConfig
+
+class HistoryConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'history'
+    verbose_name = 'History Tracking'
+
+    def ready(self):
+        """Initialize app and signal handlers"""
+        from django.dispatch import Signal
+        # Create a signal for history updates
+        self.history_updated = Signal()

history/templates/history/partials/history_timeline.html

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+<div id="history-timeline" 
+     hx-get="{% url 'history:timeline' content_type_id=content_type.id object_id=object.id %}"
+     hx-trigger="every 30s, historyUpdate from:body">
+  <div class="space-y-4">
+    {% for event in events %}
+      <div class="component-wrapper bg-white p-4 shadow-sm">
+        <div class="component-header flex items-center gap-2 mb-2">
+          <span class="text-sm font-medium">{{ event.pgh_label|title }}</span>
+          <time class="text-xs text-gray-500">{{ event.pgh_created_at|date:"M j, Y H:i" }}</time>
+        </div>
+        <div class="component-content text-sm">
+          {% if event.pgh_context.metadata.user %}
+            <div class="flex items-center gap-1">
+              <svg class="w-4 h-4" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 20 20" fill="currentColor">
+                <path fill-rule="evenodd" d="M10 9a3 3 0 100-6 3 3 0 000 6zm-7 9a7 7 0 1114 0H3z" clip-rule="evenodd" />
+              </svg>
+              <span>{{ event.pgh_context.metadata.user }}</span>
+            </div>
+          {% endif %}
+          {% if event.pgh_data %}
+            <div class="mt-2 text-gray-600">
+              <pre class="text-xs">{{ event.pgh_data|pprint }}</pre>
+            </div>
+          {% endif %}
+        </div>
+      </div>
+    {% endfor %}
+  </div>
+</div>

history/templatetags/history_tags.py

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+from django import template
+import json
+
+register = template.Library()
+
+@register.filter
+def pprint(value):
+    """Pretty print JSON data"""
+    if isinstance(value, str):
+        try:
+            value = json.loads(value)
+        except json.JSONDecodeError:
+            return value
+            
+    if isinstance(value, (dict, list)):
+        return json.dumps(value, indent=2)
+    return str(value)

history/urls.py

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+from django.urls import path
+from .views import HistoryTimelineView
+
+app_name = 'history'
+
+urlpatterns = [
+    path('timeline/<int:content_type_id>/<int:object_id>/', 
+         HistoryTimelineView.as_view(), 
+         name='timeline'),
+]

history/views.py

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+from django.views import View
+from django.shortcuts import render
+from django.http import JsonResponse
+from django.contrib.contenttypes.models import ContentType
+import pghistory
+
+def serialize_event(event):
+    """Serialize a history event for JSON response"""
+    return {
+        'label': event.pgh_label,
+        'created_at': event.pgh_created_at.isoformat(),
+        'context': event.pgh_context,
+        'data': event.pgh_data,
+    }
+
+class HistoryTimelineView(View):
+    """View for displaying object history timeline"""
+    
+    def get(self, request, content_type_id, object_id):
+        # Get content type and object
+        content_type = ContentType.objects.get_for_id(content_type_id)
+        obj = content_type.get_object_for_this_type(id=object_id)
+
+        # Get history events
+        events = pghistory.models.Event.objects.filter(
+            pgh_obj_model=content_type.model_class(),
+            pgh_obj_id=object_id
+        ).order_by('-pgh_created_at')[:25]
+
+        context = {
+            'events': events,
+            'content_type': content_type,
+            'object': obj,
+        }
+
+        if request.htmx:
+            return render(request, "history/partials/history_timeline.html", context)
+            
+        return JsonResponse({
+            'history': [serialize_event(e) for e in events]
+        })