Android WebView: call activity methods form JavaScript interface

Question

Is is possible to call main activity's methods from the JavaScript interface of a WebView object? Or to access SharedPreferences from this interface so I could read the data with my activity? I would like to let my Activity know that a specific JavaScript action occured.

Answer 1

Yes, two way communication between JavaScript and your application is possible through WebView.addJavascriptInterface(). Check this example:

http://android-developers.blogspot.com/2008/09/using-webviews.html

Answer 2

Your activity:

/*
 * entry point of the application starting the index.html of PhoneGap
 * */

package com.test.my.myApp;

import org.apache.cordova.DroidGap;

import android.os.Bundle;
import android.util.Log;

import com.google.analytics.tracking.android.EasyTracker;

public class MyOpelMainActivitiy extends DroidGap
{

    String curPhoneNumber;

    @Override
    public void onCreate(Bundle savedInstanceState)
    { 
        super.onCreate(savedInstanceState);
        super.setIntegerProperty("splashscreen", R.drawable.splash);
        super.loadUrl("file:///android_asset/www/app/index.html",15000); 

    }
    @Override
    public void onStart() {
      super.onStart();
      this.appView.addJavascriptInterface(new JsInterface(), "android");  
      curPhoneNumber = "test";

      // The rest of your onStart() code.
      EasyTracker.getInstance().activityStart(this); // Add this method.
    }

    @Override
    public void onDestroy() 
    {
        super.onDestroy();       
        com.google.analytics.tracking.android.EasyTracker.getInstance().activityStop(this);
    }

    public class JsInterface{   





            public String getPhoneNumber()
            {

                // Here call any of the public activity methods....
                return curPhoneNumber;
            }
        }
    }

---

HTMl markup:

<script type="text/javascript">
            alert(android.getPhoneNumber());
        </script>

========================================================================