--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django_extensions/admin/__init__.py	Wed Jan 20 12:37:40 2010 +0100
@@ -0,0 +1,125 @@
+#
+#    Autocomplete feature for admin panel
+#
+#    Most of the code has been written by Jannis Leidel and was updated a bit
+#    for django_extensions.
+#    http://jannisleidel.com/2008/11/autocomplete-form-widget-foreignkey-model-fields/
+#
+#    to_string_function, Satchmo adaptation and some comments added by emes
+#    (Michal Salaban)
+#
+import operator
+from django.http import HttpResponse, HttpResponseNotFound
+from django.contrib import admin
+from django.db import models
+from django.db.models.query import QuerySet
+from django.utils.encoding import smart_str
+from django.utils.translation import ugettext as _
+from django.utils.text import get_text_list
+
+from django_extensions.admin.widgets import ForeignKeySearchInput
+
+class ForeignKeyAutocompleteAdmin(admin.ModelAdmin):
+    """Admin class for models using the autocomplete feature.
+
+    There are two additional fields:
+       - related_search_fields: defines fields of managed model that
+         have to be represented by autocomplete input, together with
+         a list of target model fields that are searched for
+         input string, e.g.:
+         
+         related_search_fields = {
+            'author': ('first_name', 'email'),
+         }
+
+       - related_string_functions: contains optional functions which
+         take target model instance as only argument and return string
+         representation. By default __unicode__() method of target
+         object is used.
+    """
+
+    related_search_fields = {}
+    related_string_functions = {}
+
+    def __call__(self, request, url):
+        if url is None:
+            pass
+        elif url == 'foreignkey_autocomplete':
+            return self.foreignkey_autocomplete(request)
+        return super(ForeignKeyAutocompleteAdmin, self).__call__(request, url)
+
+    def foreignkey_autocomplete(self, request):
+        """
+        Searches in the fields of the given related model and returns the 
+        result as a simple string to be used by the jQuery Autocomplete plugin
+        """
+        query = request.GET.get('q', None)
+        app_label = request.GET.get('app_label', None)
+        model_name = request.GET.get('model_name', None)
+        search_fields = request.GET.get('search_fields', None)
+        object_pk = request.GET.get('object_pk', None)
+        try:
+            to_string_function = self.related_string_functions[model_name]
+        except KeyError:
+            to_string_function = lambda x: x.__unicode__()
+        if search_fields and app_label and model_name and (query or object_pk):
+            def construct_search(field_name):
+                # use different lookup methods depending on the notation
+                if field_name.startswith('^'):
+                    return "%s__istartswith" % field_name[1:]
+                elif field_name.startswith('='):
+                    return "%s__iexact" % field_name[1:]
+                elif field_name.startswith('@'):
+                    return "%s__search" % field_name[1:]
+                else:
+                    return "%s__icontains" % field_name
+            model = models.get_model(app_label, model_name)
+            queryset = model._default_manager.all()
+            data = ''
+            if query:
+                for bit in query.split():
+                    or_queries = [models.Q(**{construct_search(
+                        smart_str(field_name)): smart_str(bit)})
+                            for field_name in search_fields.split(',')]
+                    other_qs = QuerySet(model)
+                    other_qs.dup_select_related(queryset)
+                    other_qs = other_qs.filter(reduce(operator.or_, or_queries))
+                    queryset = queryset & other_qs
+                data = ''.join([u'%s|%s\n' % (
+                    to_string_function(f), f.pk) for f in queryset])
+            elif object_pk:
+                try:
+                    obj = queryset.get(pk=object_pk)
+                except:
+                    pass
+                else:
+                    data = to_string_function(obj)
+            return HttpResponse(data)
+        return HttpResponseNotFound()
+
+    def get_help_text(self, field_name, model_name):
+        searchable_fields = self.related_search_fields.get(field_name, None)
+        if searchable_fields:
+            help_kwargs = {
+                'model_name': model_name,
+                'field_list': get_text_list(searchable_fields, _('and')),
+            }
+            return _('Use the left field to do %(model_name)s lookups in the fields %(field_list)s.') % help_kwargs
+        return ''
+
+    def formfield_for_dbfield(self, db_field, **kwargs):
+        """
+        Overrides the default widget for Foreignkey fields if they are
+        specified in the related_search_fields class attribute.
+        """
+        if (isinstance(db_field, models.ForeignKey) and 
+            db_field.name in self.related_search_fields):
+            model_name = db_field.rel.to._meta.object_name
+            help_text = self.get_help_text(db_field.name, model_name)
+            if kwargs.get('help_text'):
+                help_text = u'%s %s' % (kwargs['help_text'], help_text)
+            kwargs['widget'] = ForeignKeySearchInput(db_field.rel,
+                                    self.related_search_fields[db_field.name])
+            kwargs['help_text'] = help_text
+        return super(ForeignKeyAutocompleteAdmin,
+            self).formfield_for_dbfield(db_field, **kwargs)