Merge pull request #46 from Buggaboo/order-dev

implemented (QueryBuilder) order

Author: vaind

README.md

@@ -144,6 +144,23 @@ final overloaded = ((text == "meh") | (text == "bleh")) | text.contains("Hello")
 box.query(overloaded as Condition).build(); // the cast is necessary due to the type analyzer
 ```
 
+Ordering
+--------
+
+The results from a query can be ordered using the `order` method, e.g.
+
+```dart
+final q = box.query(Entity_.number > 0)
+  .order(Type_.number)
+  .build();
+
+// ...
+
+final qt = box.query(Entity_.text.notNull())
+  .order(Entity_.text, flags: OBXOrderFlag.DESCENDING | OBXOrderFlag.CASE_SENSITIVE)
+  .build();
+```
+
 Basic technical approach
 ------------------------
 ObjectBox offers a [C API](https://github.com/objectbox/objectbox-c) which can be called by [Dart FFI](https://dart.dev/server/c-interop).

lib/src/query/builder.dart

@@ -17,8 +17,10 @@ class QueryBuilder<T> {
     }
   }
 
+  _createBuilder() => _cBuilder ??= bindings.obx_qb_create(_store.ptr, _entityId);
+
   Query build() {
-    _cBuilder = bindings.obx_qb_create(_store.ptr, _entityId);
+    _createBuilder();
 
     if (0 == _queryCondition.apply(this, true)) {
       _throwExceptionIfNecessary();
@@ -30,15 +32,19 @@ class QueryBuilder<T> {
       checkObx(bindings.obx_qb_close(_cBuilder));
     }
   }
+
+  QueryBuilder<T> order(QueryProperty p, {int flags=0}) {
+    _createBuilder();
+    checkObx(bindings.obx_qb_order(_cBuilder, p._propertyId, flags));
+    return this;
+  }
 }
 
 /*  // Not done yet
     obx_qb_bytes_eq_dart_t obx_qb_bytes_equal;
     obx_qb_bytes_lt_gt_dart_t obx_qb_bytes_greater, obx_qb_bytes_less;
 
     obx_qb_param_alias_dart_t obx_qb_param_alias;
-
-    obx_qb_order_dart_t obx_qb_order;
 */
 
 //////

test/query_test.dart

@@ -2,6 +2,7 @@ import "package:test/test.dart";
 import "package:objectbox/objectbox.dart";
 import "entity.dart";
 import 'test_env.dart';
+import "package:objectbox/src/bindings/constants.dart" show OBXOrderFlag;
 
 void main() {
   TestEnv env;
@@ -356,6 +357,41 @@ void main() {
     }
   });
 
+  test(".order queryBuilder", () {
+    box.put(TestEntity.initText("World"));
+    box.put(TestEntity.initText("Hello"));
+    box.put(TestEntity.initText("HELLO"));
+    box.put(TestEntity.initText("World"));
+    box.put(TestEntity.initText("Goodbye"));
+    box.put(TestEntity.initText("Cruel"));
+    box.put(TestEntity.initInteger(1337));
+
+    final text = TestEntity_.text;
+
+    final condition = text.notNull();
+
+    final query = box.query(condition)
+      .order(text)
+      .build();
+
+    final queryWithFlags = box.query(condition)
+      .order(text, flags: OBXOrderFlag.DESCENDING | OBXOrderFlag.CASE_SENSITIVE)
+      .build();
+
+    final result1 = query.find().map((e) => e.text).toList();
+    final result2 = queryWithFlags.find().map((e) => e.text).toList();
+
+    expect("Cruel", result1[0]);
+    expect("World", result2[0]);
+    expect("Hello", result1[2]);
+    expect("Hello", result2[2]);
+    expect("HELLO", result1[3]);
+    expect("HELLO", result2[3]);
+
+    query.close();
+    queryWithFlags.close();
+  });
+
   tearDown(() {
     env.close();
   });