unhandled promise rejection

[Ideasrefined]

Version

Tell us which versions you are using:

• react-native-ble-manager v_latest as of 4thAug2017

• react-native
  react-native-cli: 2.0.1
  react-native: 0.47.0

• iOS/Android v.Android 7.1.1

I have linked ble-manager library using react-native link. I followed the instructions to change minSDK version to 18.

I am getting the following Warning when I use

"BleManager.start({showAlert: false, allowDuplicates: false});"

Possible Unhandled Promise Rejection (id: 0):
TypeError: Cannot read property 'start' of undefined
TypeError: Cannot read property 'start' of undefined

I have traced the problem to the
bleManager.start call in the following function in BleManager.js.

start(options) {
    return new Promise((fulfill, reject) => {
      if (options == null) {
        options = {};
      }
      console.log("Start BLE")
      bleManager.start(options, (error) => {
        if (error) {
          reject(error);
        } else {
          fulfill();
        }
      });
    });
  }

I am not sure what went wrong or how to fix it.

[marcosinigaglia]

Hi, try to install manually.

[Ideasrefined]

Update: Compiling and running included example results in the same error.

now moving to installing it manually But I am skeptical.

[Ideasrefined]

Update # 2:
Tried installing / linking using manual procedure described in the readme. After all the steps when I run "react-native run-android" I get the following error :-

/home/enigma/codes/react/native/innovateBLE/node_modules/react-native-ble-manager/android/src/main/java/it/innove/BleManagerPackage.java:26: error: method does not override or implement a method from a supertype
        @Override
        ^
Note: /home/enigma/codes/react/native/innovateBLE/node_modules/react-native-ble-manager/android/src/main/java/it/innove/LegacyScanManager.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error
:react-native-ble-manager:compileReleaseJavaWithJavac FAILED

FAILURE: Build failed with an exception.

[marcosinigaglia]

Try with RN 0.46, I don't know if there are breaking changes in 0.47

[virdesai]

For RN 0.47, change

public BleManagerPackage() {}

@Override
public List<NativeModule> createNativeModules(ReactApplicationContext reactApplicationContext) {
	List<NativeModule> modules = new ArrayList<>();

	modules.add(new BleManager(reactApplicationContext));
	return  modules;
}

@Override
public List<Class<? extends JavaScriptModule>> createJSModules() {
	return new ArrayList<>();
}

@Override
public List<ViewManager> createViewManagers(ReactApplicationContext reactApplicationContext) {
	return Collections.emptyList();
}

to

public BleManagerPackage() {}

@Override
public List<NativeModule> createNativeModules(ReactApplicationContext reactApplicationContext) {
	List<NativeModule> modules = new ArrayList<>();

	modules.add(new BleManager(reactApplicationContext));
	return  modules;
}

public List<Class<? extends JavaScriptModule>> createJSModules() {
	return new ArrayList<>();
}

@Override
public List<ViewManager> createViewManagers(ReactApplicationContext reactApplicationContext) {
	return Collections.emptyList();
}

[Ideasrefined]

Works as is for RN 0.46

[rgstephens]

I've also run into this issue with 0.47. Seems like this issue should be left open.

[nomoreboredom]

For future reference, RN version 0.53, Typescript, I needed to import as import * as BleManager from 'react-native-ble-manager';

[dcmayankavi]

I'm facing same problem with below configuration:

"react": "16.11.0",
"react-native": "0.62.2",
"react-native-ble-manager": "7.2.0"

Android version: 10

[shouer]

I'm facing same problem with below configuration:

"react": "16.8.3",
"react-native": "0.59.5",
"react-native-ble-manager": "^7.3.0",

Android version: 10

[asukiaaa]

It depended on importing way in my case.

// import * as BleManager from "react-native-ble-manager" // Bad
import BleManager from "react-native-ble-manager" // OK

BleManager.start()

    "react": "18.2.0",
    "react-native": "0.74.2",
    "react-native-ble-manager": "^11.5.4"