Asynchronous suggestions for field values with a limit

README.rst

@@ -236,6 +236,23 @@ In this example we've defined a custom GroupNameField that sorts suggestions
 for group names by popularity (no. of users in a group) instead of default
 alphabetical sorting.
 
+**Set value suggestions limit**
+
+By default, field value suggestions number is limited to 50 entries.
+If you want to change this, override ``suggestions_limit`` field in your custom schema.
+
+.. code:: python
+
+    from djangoql.schema import DjangoQLSchema, StrField
+
+
+    class UserQLSchema(DjangoQLSchema):
+        exclude = (Book,)
+        suggest_options = {
+            Group: ['name'],
+        }
+        suggestions_limit = 30  # Set a desired limit here
+
 **Custom search lookup**
 
 DjangoQL base fields provide two basic methods that you can override to

djangoql/admin.py

@@ -123,6 +123,11 @@ def get_urls(self):
                     )),
                     name='djangoql_syntax_help',
                 ),
+                url(
+                    r'^suggestions/$',
+                    self.admin_site.admin_view(self.field_value_suggestions),
+                    name='djangoql_field_value_suggestions',
+                ),
             ]
         return custom_urls + super(DjangoQLSearchMixin, self).get_urls()
 
@@ -132,3 +137,12 @@ def introspect(self, request):
             content=json.dumps(response, indent=2),
             content_type='application/json; charset=utf-8',
         )
+
+    def field_value_suggestions(self, request):
+        suggestions = self.djangoql_schema(self.model)\
+            .get_field_instance(self.model, request.GET['field_name'])\
+            .get_sugestions(request.GET['text'])
+        return HttpResponse(
+            content=json.dumps(list(suggestions), indent=2),
+            content_type='application/json; charset=utf-8',
+        )

djangoql/schema.py

@@ -27,7 +27,7 @@ class DjangoQLField(object):
     value_types_description = ''
 
     def __init__(self, model=None, name=None, nullable=None,
-                 suggest_options=None):
+                 suggest_options=None, suggestions_limit=None):
         if model is not None:
             self.model = model
         if name is not None:
@@ -36,12 +36,16 @@ def __init__(self, model=None, name=None, nullable=None,
             self.nullable = nullable
         if suggest_options is not None:
             self.suggest_options = suggest_options
+        if suggestions_limit is not None:
+            self.suggestions_limit = suggestions_limit
+
+    def _get_options_queryset(self):
+        return self.model.objects.order_by(self.name)
 
     def as_dict(self):
         return {
             'type': self.type,
             'nullable': self.nullable,
-            'options': list(self.get_options()) if self.suggest_options else [],
         }
 
     def _field_choices(self):
@@ -54,15 +58,27 @@ def _field_choices(self):
 
     def get_options(self):
         """
-        Override this method to provide custom suggestion options
+        DEPRECATED: field value suggestions are now using get_sugestions() method
         """
         choices = self._field_choices()
         if choices:
             return [c[1] for c in choices]
         else:
-            return self.model.objects.\
-                order_by(self.name).\
-                values_list(self.name, flat=True)
+            return self._get_options_queryset().values_list(self.name, flat=True)
+
+    def get_sugestions(self, text):
+        """
+        Override this method to provide custom suggestion options
+        """
+        choices = self._field_choices()
+        if choices:
+            return [c[1] for c in choices]
+
+        kwargs = {'{}__icontains'.format(self.name): text}
+
+        return self._get_options_queryset()\
+            .filter(**kwargs)[:self.suggestions_limit]\
+            .values_list(self.name, flat=True)
 
     def get_lookup_name(self):
         """
@@ -267,12 +283,13 @@ class RelationField(DjangoQLField):
     type = 'relation'
 
     def __init__(self, model, name, related_model, nullable=False,
-                 suggest_options=False):
+                 suggest_options=False, suggestions_limit=None):
         super(RelationField, self).__init__(
             model=model,
             name=name,
             nullable=nullable,
             suggest_options=suggest_options,
+            suggestions_limit=suggestions_limit,
         )
         self.related_model = related_model
 
@@ -290,6 +307,7 @@ class DjangoQLSchema(object):
     include = ()  # models to include into introspection
     exclude = ()  # models to exclude from introspection
     suggest_options = None
+    suggestions_limit = 50
 
     def __init__(self, model):
         if not inspect.isclass(model) or not issubclass(model, models.Model):
@@ -397,6 +415,7 @@ def get_field_instance(self, model, field_name):
         field_kwargs['suggest_options'] = (
             field.name in self.suggest_options.get(model, [])
         )
+        field_kwargs['suggestions_limit'] = self.suggestions_limit
         field_instance = field_cls(**field_kwargs)
         # Check if suggested options conflict with field type
         if field_cls != StrField and field_instance.suggest_options:

djangoql/static/djangoql/js/completion.js

@@ -807,9 +807,12 @@
               }.bind(this);
             }
             this.highlightCaseSensitive = this.valuesCaseSensitive;
-            this.suggestions = field.options.map(function (f) {
-              return suggestion(f, snippetBefore, snippetAfter);
-            });
+            this.loadSuggestions(
+              context.prefix, context.field, function (responseData) {
+                this.suggestions = responseData.map(function (f) {
+                  return suggestion(f, snippetBefore, snippetAfter);
+                });
+              }.bind(this));
           } else if (field.type === 'bool') {
             this.suggestions = [
               suggestion('True', '', ' '),
@@ -842,6 +845,24 @@
       } else {
         this.selected = null;
       }
+    },
+    // Load suggestions from backend
+    loadSuggestions: function (text, fieldName, callback) {
+      var xhr = new XMLHttpRequest();
+      var params = new URLSearchParams();
+      params.set('text', text);
+      params.set('field_name', fieldName);
+      xhr.open(
+        'GET',
+        this.options.suggestionsUrl + params.toString(),
+        true
+      );
+      xhr.onload = function () {
+        if (xhr.readyState === 4 && xhr.status === 200) {
+          callback(JSON.parse(xhr.responseText));
+        }
+      };
+      xhr.send();
     }
 
   };

djangoql/static/djangoql/js/completion_admin.js

@@ -95,6 +95,7 @@
     djangoQL = new DjangoQL({
       completionEnabled: QLEnabled,
       introspections: 'introspect/',
+      suggestionsUrl: 'suggestions/?',
       syntaxHelp: 'djangoql-syntax/',
       selector: 'textarea[name=q]',
       autoResize: true

test_project/core/admin.py

@@ -5,7 +5,7 @@
 from django.utils.timezone import now
 
 from djangoql.admin import DjangoQLSearchMixin
-from djangoql.schema import DjangoQLSchema, IntField
+from djangoql.schema import DjangoQLSchema, IntField, StrField
 
 from .models import Book
 
@@ -89,8 +89,9 @@ def years_ago(self, n):
 class UserQLSchema(DjangoQLSchema):
     exclude = (Book,)
     suggest_options = {
-        Group: ['name'],
+        Group: ['name'], User: ['username']
     }
+    suggestions_limit = 30
 
     def get_fields(self, model):
         fields = super(UserQLSchema, self).get_fields(model)

test_project/core/templates/completion_demo.html

@@ -40,7 +40,10 @@
         // doesn't fit, and shrink back when text is removed. The purpose
         // of this is to see full search query without scrolling, could be
         // helpful for really long queries.
-        autoResize: true
+        autoResize: true,
+
+        // An URL to load field value suggestions
+        suggestionsUrl: 'suggestions/?'
       });
     });
   </script>

test_project/core/tests/test_schema.py

@@ -166,3 +166,37 @@ def test_validation_fail(self):
                 self.fail('This query should\'t pass validation: %s' % query)
             except DjangoQLSchemaError as e:
                 pass
+
+
+class UserQLSchema(DjangoQLSchema):
+    include = (User,)
+    suggestions_limit = 30
+
+
+class BookQLSchema(DjangoQLSchema):
+    include = (Book,)
+    suggestions_limit = 2
+
+
+class DjangoQLFieldTest(TestCase):
+    def setUp(self):
+        for i in range(2, 70):
+            User.objects.create(username='a' * i)
+
+    def test_get_suggestions_limit_doesnt_affect_choices(self):
+        result = BookQLSchema(Book).get_field_instance(Book, 'genre').get_sugestions('blah')
+        self.assertEqual(len(result), len(Book.GENRES))
+
+    def test_get_suggestions_with_string_field_should_be_limited(self):
+        suggestions = IncludeUserGroupSchema(User).get_field_instance(User, 'username').get_sugestions('aaa')
+        self.assertEqual(len(suggestions), 50)
+
+    def test_get_suggestions_with_custom_limit(self):
+        suggestions = UserQLSchema(User).get_field_instance(User, 'username').get_sugestions('aaa')
+        self.assertEqual(len(suggestions), UserQLSchema.suggestions_limit)
+
+    def test_suggestions_should_contain_query_string(self):
+        query_string = 'aaa'
+        suggestions = UserQLSchema(User).get_field_instance(User, 'username').get_sugestions(query_string)
+        for suggestion in suggestions:
+            self.assertIn(query_string, suggestion)

test_project/core/views.py

@@ -3,6 +3,7 @@
 from django.contrib.auth.models import Group, User
 from django.shortcuts import render
 from django.views.decorators.http import require_GET
+from django.http.response import HttpResponse
 
 from djangoql.exceptions import DjangoQLError
 from djangoql.queryset import apply_search
@@ -30,3 +31,14 @@ def completion_demo(request):
         'search_results': query,
         'introspections': json.dumps(UserQLSchema(query.model).as_dict()),
     })
+
+
+@require_GET
+def suggestions(request):
+    payload = UserQLSchema(User) \
+        .get_field_instance(User, request.GET['field_name']) \
+        .get_sugestions(request.GET['text'])
+    return HttpResponse(
+        content=json.dumps(list(payload), indent=2),
+        content_type='application/json; charset=utf-8',
+    )

test_project/test_project/urls.py

@@ -17,12 +17,13 @@
 from django.conf.urls import url, include
 from django.contrib import admin
 
-from core.views import completion_demo
+from core.views import completion_demo, suggestions
 
 
 urlpatterns = [
     url(r'^admin/', admin.site.urls),
     url(r'^$', completion_demo),
+    url(r'^suggestions/', suggestions),
 ]
 
 if settings.DEBUG and settings.DJDT: