Enhance exam search widget: add error handling for model retrieval and improve query parsing

generic/views.py

@@ -6658,7 +6658,14 @@ def exam_search_widget(request):
     # Support wildcard queries
     q = q_raw
 
-    model = apps.get_model(model_label)
+    try:
+        model = apps.get_model(model_label) if model_label else None
+    except Exception:
+        model = None
+
+    # If we couldn't resolve a model, return empty fragment rather than raising
+    if model is None:
+        return HttpResponse("")
 
     # Helper to parse optional boolean GET params
     def _get_bool_param(name):
@@ -6680,14 +6687,73 @@ def exam_search_widget(request):
         return False
 
     # Build queryset
-    qs = None
-    field_lookups = ["name__icontains"]
-    for lookup in field_lookups:
-        qs = model.objects.filter(**{lookup: q})
-        if qs.exists():
-                break
+    qs = model.objects.none()
 
-    logger.error(qs)
+    # Support field-prefixed queries like `name:term`, `code:term`, `id:123`, `date:YYYY-MM-DD`, `type:app`
+    field_match = re.match(r'^(?P<field>name|code|id|pk|date|type):\s*(?P<term>.+)$', q, flags=re.I)
+    def _field_exists(mdl, field_name):
+        try:
+            mdl._meta.get_field(field_name)
+            return True
+        except Exception:
+            return False
+
+    if field_match:
+        f = field_match.group('field').lower()
+        term = field_match.group('term').strip()
+        try:
+            if f in ('id', 'pk'):
+                qs = model.objects.filter(pk=int(term))
+            elif f == 'name':
+                qs = model.objects.filter(name__icontains=term)
+            elif f == 'code':
+                # try a few plausible code field names if present
+                lookups = []
+                for fn in ('code', 'short_code', 'identifier'):
+                    if _field_exists(model, fn):
+                        lookups.append(f"{fn}__icontains")
+                if lookups:
+                    from django.db.models import Q
+                    qobj = Q()
+                    for lk in lookups:
+                        qobj |= Q(**{lk: term})
+                    qs = model.objects.filter(qobj)
+                else:
+                    qs = model.objects.none()
+            elif f == 'date':
+                # try a few common date field names
+                date_lookups = []
+                for fn in ('date', 'exam_date', 'start_date'):
+                    if _field_exists(model, fn):
+                        date_lookups.append(fn)
+                if date_lookups:
+                    from django.db.models import Q
+                    qobj = Q()
+                    for fn in date_lookups:
+                        qobj |= Q(**{f"{fn}__startswith": term})
+                    qs = model.objects.filter(qobj)
+                else:
+                    qs = model.objects.none()
+            elif f == 'type':
+                # restrict by app_label or model name match
+                if term.lower() in (model._meta.app_label.lower(), model._meta.model_name.lower()):
+                    qs = model.objects.all()
+                else:
+                    qs = model.objects.none()
+        except Exception:
+            qs = model.objects.none()
+    else:
+        # Default: search name and, where available, code-like fields
+        field_lookups = ["name__icontains"]
+        for fn in ('code', 'short_code', 'identifier'):
+            if _field_exists(model, fn):
+                field_lookups.append(f"{fn}__icontains")
+
+        from django.db.models import Q
+        qobj = Q()
+        for lk in field_lookups:
+            qobj |= Q(**{lk: q})
+        qs = model.objects.filter(qobj)
 
     # Limit results
     limit = 50 if q in ("*", "%") else 10