SyncClient: support adding and removing filter variables #280

Author: greenrobot-team

CHANGELOG.md

@@ -21,6 +21,10 @@ For more insights into what changed in the ObjectBox C++ core, [check the Object
 - Remove deprecated `ValidateOnOpenMode` constants, use `ValidateOnOpenModePages` instead.
 - Remove deprecated DAOcompat compatibility query methods. Use the regular query API instead.           
 
+### Sync
+
+- Support configuring [Sync filter](https://sync.objectbox.io/sync-server/sync-filters) variables on a `SyncClient`.
+
 ## 4.3.1 - 2025-08-12
 
 - Requires at least Kotlin compiler and standard library 1.7.

objectbox-java/src/main/java/io/objectbox/sync/SyncClient.java

@@ -127,6 +127,35 @@ public interface SyncClient extends Closeable {
      */
     void setSyncTimeListener(@Nullable SyncTimeListener timeListener);
 
+    /**
+     * Adds or replaces a Sync filter variable value for the given name.
+     * <p>
+     * Eventually, existing values for the same name are replaced.
+     * <p>
+     * Sync client filter variables can be used in server-side Sync filters to filter out objects that do not match the
+     * filter. Filter variables must be added before login, so before calling {@link #start()}.
+     *
+     * @see #removeFilterVariable
+     * @see #removeAllFilterVariables
+     */
+    void putFilterVariable(String name, String value);
+
+    /**
+     * Removes a previously added Sync filter variable value.
+     *
+     * @see #putFilterVariable
+     * @see #removeAllFilterVariables
+     */
+    void removeFilterVariable(String name);
+
+    /**
+     * Removes all previously added Sync filter variable values.
+     *
+     * @see #putFilterVariable
+     * @see #removeFilterVariable
+     */
+    void removeAllFilterVariables();
+
     /**
      * Updates the credentials used to authenticate with the server. This should not be required during regular use.
      * The original credentials were passed when building sync client.

objectbox-java/src/main/java/io/objectbox/sync/SyncClientImpl.java

@@ -187,6 +187,18 @@ public void setSyncListener(@Nullable SyncListener listener) {
         setSyncChangeListener(listener);
     }
 
+    public void putFilterVariable(String name, String value) {
+        nativePutFilterVariable(getHandle(), name, value);
+    }
+
+    public void removeFilterVariable(String name) {
+        nativeRemoveFilterVariable(getHandle(), name);
+    }
+
+    public void removeAllFilterVariables() {
+        nativeRemoveAllFilterVariables(getHandle());
+    }
+
     @Override
     public void setLoginCredentials(SyncCredentials credentials) {
         if (credentials == null) {
@@ -350,6 +362,15 @@ public ObjectsMessageBuilder startObjectsMessage(long flags, @Nullable String to
 
     private native void nativeStop(long handle);
 
+    // extern "C" JNIEXPORT void JNICALL Java_io_objectbox_sync_SyncClientImpl_nativePutFilterVariable(JNIEnv* env, jobject, jlong handle, jstring name, jstring value)
+    private native void nativePutFilterVariable(long handle, String name, String value);
+
+    // extern "C" JNIEXPORT void JNICALL Java_io_objectbox_sync_SyncClientImpl_nativeRemoveFilterVariable(JNIEnv* env, jobject, jlong handle, jstring name)
+    private native void nativeRemoveFilterVariable(long handle, String name);
+
+    // extern "C" JNIEXPORT void JNICALL Java_io_objectbox_sync_SyncClientImpl_nativeRemoveAllFilterVariables(JNIEnv* env, jobject, jlong handle)
+    private native void nativeRemoveAllFilterVariables(long handle);
+
     private native void nativeSetLoginInfo(long handle, long credentialsType, @Nullable byte[] credentials);
 
     private native void nativeSetLoginInfoUserPassword(long handle, long credentialsType, String username, String password);

tests/objectbox-java-test/src/test/java/io/objectbox/sync/ConnectivityMonitorTest.java

@@ -1,16 +1,31 @@
+/*
+ * Copyright 2025 ObjectBox Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package io.objectbox.sync;
 
-import io.objectbox.sync.listener.SyncTimeListener;
 import org.junit.Test;
 
-
 import javax.annotation.Nullable;
 
 import io.objectbox.sync.listener.SyncChangeListener;
 import io.objectbox.sync.listener.SyncCompletedListener;
 import io.objectbox.sync.listener.SyncConnectionListener;
 import io.objectbox.sync.listener.SyncListener;
 import io.objectbox.sync.listener.SyncLoginListener;
+import io.objectbox.sync.listener.SyncTimeListener;
 
 
 import static org.junit.Assert.assertEquals;
@@ -153,6 +168,18 @@ public void setSyncChangeListener(@Nullable SyncChangeListener listener) {
         public void setSyncTimeListener(@Nullable SyncTimeListener timeListener) {
         }
 
+        @Override
+        public void putFilterVariable(String name, String value) {
+        }
+
+        @Override
+        public void removeFilterVariable(String name) {
+        }
+
+        @Override
+        public void removeAllFilterVariables() {
+        }
+
         @Override
         public void setLoginCredentials(SyncCredentials credentials) {
         }