Cannot switch to WebView when testing Hydrid App

[louis57]

I am writing automation tests for a Hydrid App on Android. I have 2 problems:

1. From Appium Inspector, I see an element with attribute

   resource-id: login_button

   so I click this button with

   androidDriver.findElement(By.id("login-button")).click();

   and I get this error:

   "An element could not be located with..."

   Of course if I find element with

   classname "android.widget.Button"

   then it works. I asked developer, normally, resource-id would be like

   resource-id: <APP_PACKAGE_NAME>:id/login_button

   But he said for hydrid app he doesn't have bundleID (APP_PACKAGE_NAME). Is it correct that we don't have bundleID for Hydrid APP? And why Appium Inspector can see

   "resource-id: login_button"

   but this element could not be found and clickable?

2. So I also tried to switch context to WEBVIEW, with this code:

   Set<String> contextHandles = appiumDriver.getContextHandles();
   Map<String,String> hashMap= new HashMap<String,String>();
       for (String contextname : contextHandles){
   	    if (contextname.contains("NATIVE")){
   		    hashMap.put("native", contextname);
   	    } else {
   		    hashMap.put("webview", contextname);
   	    }
       }
       //webview 
       androidDriver.context(hashMap.get("webview"));

   contextHandles has 2 values: NATIVE_APP and WEBVIEW_<APP_PACKAGE_NAME>. But when I set context to webview, I get error:

   io.appium.java_client.NoSuchContextException: No such context found.

The App is built with Ionic 2 / Angular 2. This is what I see on Chrome://inspect

Can anyone please help? Thanks