Allow alphabetically sorted searches on the Django ORM backend

docs/customization.rst

@@ -27,7 +27,11 @@ You can enable this type of behavior by defining an ``autocomplete_create`` clas
 Custom Search Field
 ===================
 
-By default, the autocomplete widget will match input against the ``title`` field on your model. If you're using a model that doesn't have a ``title`` attribute, or you just want to search using a different field, you can customize which field it matches against by defining an ``autocomplete_search_field`` property on your model:
+If your model is indexed using the native Wagtail `indexing methods <https://docs.wagtail.io/en/latest/topics/search/indexing.html>`_, then the configured backend will be used to search accross all indexed fields.
+You can narrow the scope by setting the ``autocomplete_search_field`` on the model like in the example to only search one field.
+
+If your model is not indexed then the native Django ORM is used to match input against the ``title`` field on your model.
+If you're using a model that doesn't have a ``title`` attribute, or you just want to search using a different field, you can customize which field it matches against by defining an ``autocomplete_search_field`` property on your model:
 
 .. code-block:: python
 
@@ -52,6 +56,12 @@ By default, the autocomplete widget will match input against the ``title`` field
         MyModel.objects.filter(my_special_field__icontains='part')
 
     Additionally, this means that ``autocomplete_search_field`` *must* be a model field and cannot be an arbitrary property or method.
+
+To use a different lookup behaviour on the Django ORM you can specify a tuple with the lookup type on your model's autocomplete_search_field:
+
+ .. code-block:: python
+
+        autocomplete_search_field = ('my_special_field', 'istartswith')
 
 Custom Label Display
 ====================

wagtailautocomplete/views.py

@@ -8,6 +8,14 @@
 from django.http import (HttpResponseBadRequest, HttpResponseForbidden,
                          JsonResponse)
 from django.views.decorators.http import require_GET, require_POST
+from wagtail import VERSION
+
+if VERSION > (2, 0):
+    from wagtail.search.backends import get_search_backend
+    from wagtail.search.index import Indexed
+else:
+    from wagtail.wagtailsearch.backends import get_search_backend
+    from wagtail.wagtailsearch.index import Indexed
 
 
 def render_page(page):
@@ -64,10 +72,24 @@ def search(request):
     except ValueError:
         return HttpResponseBadRequest()
 
-    field_name = getattr(model, 'autocomplete_search_field', 'title')
-    filter_kwargs = dict()
-    filter_kwargs[field_name + '__icontains'] = search_query
-    queryset = model.objects.filter(**filter_kwargs)
+    field_name = getattr(model, 'autocomplete_search_field', None)
+    custom_lookup = isinstance(field_name, (list, tuple))
+    if not custom_lookup and issubclass(model, Indexed):
+        search_backend = get_search_backend()
+        if field_name:
+            queryset = search_backend.search(search_query, model, fields=[field_name])
+        else:
+            queryset = search_backend.search(search_query, model)
+    else:
+        lookup_type = 'icontains'
+        if custom_lookup:
+            lookup_type = field_name[1]
+            field_name = field_name[0]
+        field_name = field_name if field_name else 'title'
+        filter_kwargs = dict()
+        filter_kwargs["{0}__{1}".format(field_name, lookup_type)] = search_query
+        queryset = model.objects.filter(**filter_kwargs)
+
 
     if getattr(queryset, 'live', None):
         # Non-Page models like Snippets won't have a live/published status