feat: avoidDuplicates option on startScanning method

README.md

@@ -119,6 +119,10 @@ A few of the optional params require a bit of explanation:
 #### seconds
 Scanning for peripherals drains the battery quickly, so you better not scan any longer than necessary. If a peripheral is in range and not engaged in another connection it usually pops up in under a second. If you don't pass in a number of seconds you will need to manually call `stopScanning`.
 
+#### avoidDuplicates
+Set this to true if you don't want duplicates with the same serviceUUID reported in "onDiscovered" callback.
+If true, only the first discovered peripheral with the same serviceUUID will be reported.
+
 #### skipPermissionCheck
 Set this to true if you don't want the plugin to check (and request) the required Bluetooth permissions.
 Particularly useful if you're running this function on a non-UI thread (ie. a Worker).

src/bluetooth.android.ts

@@ -1506,6 +1506,23 @@ export class Bluetooth extends BluetoothCommon {
                     //     }
                     // }
 
+                    let onPeripheralDiscovered;
+
+                    if (args.onDiscovered) {
+                        if (args.avoidDuplicates) {
+                            const discoveredUUIDs = [];
+                            onPeripheralDiscovered = (data: Peripheral) => {
+                                const hasBeenDiscovered = discoveredUUIDs.includes(data.UUID);
+                                if (!hasBeenDiscovered) {
+                                    discoveredUUIDs.push(data.UUID);
+                                    args.onDiscovered(data);
+                                }
+                            };
+                        } else {
+                            onPeripheralDiscovered = args.onDiscovered;
+                        }
+                    }
+
                     const filters = args.filters || [];
 
                     if (this.scanningReferTimer) {
@@ -1519,7 +1536,7 @@ export class Bluetooth extends BluetoothCommon {
                                 uuids.push(stringToUuid(f.serviceUUID));
                             }
                         });
-                        this.LeScanCallback.onPeripheralDiscovered = args.onDiscovered;
+                        this.LeScanCallback.onPeripheralDiscovered = onPeripheralDiscovered;
                         const didStart = uuids.length === 0 ? this.adapter.startLeScan(this.LeScanCallback) : this.adapter.startLeScan(uuids, this.LeScanCallback);
                         if (Trace.isEnabled()) {
                             CLog(CLogTypes.info, methodName, '---- PreLollipop ---- didStart scanning:', didStart, JSON.stringify(uuids));
@@ -1577,7 +1594,7 @@ export class Bluetooth extends BluetoothCommon {
                             scanSettings.setCallbackType(androidCallbackType(callbackType));
                         }
 
-                        this.scanCallback.onPeripheralDiscovered = args.onDiscovered;
+                        this.scanCallback.onPeripheralDiscovered = onPeripheralDiscovered;
                         this.adapter.getBluetoothLeScanner().startScan(scanFilters, scanSettings.build(), this.scanCallback);
                         if (Trace.isEnabled()) {
                             CLog(CLogTypes.info, methodName, ' ---- PostLollipop ---- didStart scanning:', JSON.stringify(filters));

src/bluetooth.common.ts

@@ -220,6 +220,12 @@ export interface StartScanningOptions {
      */
     seconds?: number;
 
+    /**
+     * Avoid duplicates with the same serviceUUID in "onDiscovered" callback.
+     * If true, only the first discovered peripheral with the same serviceUUID will be reported.
+     */
+    avoidDuplicates?: boolean;
+
     /**
      * This callback is invoked when a peripheral is found.
      */

src/bluetooth.ios.ts

@@ -823,8 +823,13 @@ export class Bluetooth extends BluetoothCommon {
                     CLog(CLogTypes.info, methodName, '---- services:', services);
                 }
 
+                const options: NSMutableDictionary<any, any> = new (NSMutableDictionary as any)();
+                if (!args.avoidDuplicates) {
+                    options.setObjectForKey(true, CBCentralManagerScanOptionAllowDuplicatesKey);
+                }
+
                 // TODO: check on the services as any casting
-                this.centralManager.scanForPeripheralsWithServicesOptions(services as any, null);
+                this.centralManager.scanForPeripheralsWithServicesOptions(services as any, options);
                 if (this.scanningReferTimer) {
                     clearTimeout(this.scanningReferTimer.timer);
                     this.scanningReferTimer.resolve();