How to run cordova plugin in Android background service?

[mehsen]

I am working on mobile application developed on [cordova][1] . I want to implement a background service that do some work like open socket connection syncronise local database with remote one and notify the users on new remote pushes etc . The point is I have this code implemented in javascript but I want execute it i background.

 
I searched internet for a cordova background service plugin.

   - katzer/cordova-plugin-background-mode
   - jocull/phonegap-backgroundjs
   - [red-folder]

 The best one I think is [red-folder] but it is just for android and it does not let me to write javascript to be executed in background. but just exchange json between java and javascript.

I have read some topics about background service in android these are useful ones I found:


   - [create-a-service-on-android-with-phonegap-application]
   - [simple-android-service-example-code-description-start-stop-service]
   - [android-using-webview-outside-an-activity-context]

So I started writing cordova plugin (primarily on android) to execute the javascript code in background. I created a webview from the background service to execute the javascript from it. This works fine when I execute normal javascript but when it comes to cordova plugins js it fails for example the device `device.uuid` gives `null`.



This is the java service  code:

public void onStart(Intent intent, int startId) {
          Toast.makeText(this, "My Happy Service Started", Toast.LENGTH_LONG).show();

               createBackGroundView();
               super.onStart(intent,startId);
   }


          public void createBackGroundView(){


       WindowManager windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
      LayoutParams params = new WindowManager.LayoutParams(
                       android.view.ViewGroup.LayoutParams.WRAP_CONTENT,
                       android.view.ViewGroup.LayoutParams.WRAP_CONTENT,
                       WindowManager.LayoutParams.TYPE_PHONE,
                       WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
                       PixelFormat.TRANSLUCENT
               );

       params.gravity = Gravity.TOP | Gravity.LEFT;
       params.x = 0;
       params.y = 0;
       params.width = 200;
       params.height = 200;

       LinearLayout view = new LinearLayout(this);

       view.setLayoutParams(new RelativeLayout.LayoutParams(
                        android.view.ViewGroup.LayoutParams.MATCH_PARENT,
                        android.view.ViewGroup.LayoutParams.MATCH_PARENT
                ));

       WebView wv = new WebView(this);
       wv.setLayoutParams(new LinearLayout.LayoutParams(
                        android.view.ViewGroup.LayoutParams.MATCH_PARENT,
                        android.view.ViewGroup.LayoutParams.MATCH_PARENT
                ));
       view.addView(wv);
       wv.getSettings().setJavaScriptEnabled(true);
       wv.setWebChromeClient(new WebChromeClient());
                wv.loadUrl("file:///android_asset/www/background.html");
       wv.setWebViewClient(new WebViewClient() {

@Override
public void onReceivedError(final WebView view, int errorCode,
String description, final String failingUrl) {
Log.d("Error","loading web view");
super.onReceivedError(view, errorCode, description, failingUrl);
}
});

       windowManager.addView(view, params);

         }

         

There is no error in the logcat.
So I tried to write the device object on the screen and that's what I get :
       
     
     

document.write(JSON.stringify(window.device))

And this is the result :


  { available : false, 
        plaform : null , 
        version : null , 
        uuid : null ,  
        cordova : null ,
        model : null 
       }

Any help about this problem ?

[Kaloyan]

Hi Mehsen,

Thank you for bringing this issue to our community.

Even as such inquiry is beyond the scope of our support services, I believe the AppBuilder forum is good place for such questions. Further, you can also try posting it on StackOverflow.

Regards,
Kaloyan
Telerik

 

 

[Kaloyan]

Hi again Mehsen,

A colleague of mine noted that you mght need to use CordovaWebView instead of the default WebView in Android devices. Here is a good reference about this. If it works, here you will find the iOS one.

I hope it helps.

Regards,
Kaloyan
Telerik