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.
3 Answers
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
5 Comments
Krzychu
OK, this sort of solves my problem. In the example given by you it works, because DemoJavaScriptInterface is a subclass of WebViewDemo class and can access its methods. But is there a way to achieve it when it is not a subclass?
Caner
It doesn't use any of
WebViewDemo methods. It only uses mHandler and that could be passed to the constructor.Krzychu
I tried to pass the
mHandler but the main Activity is still inaccessible. When I try mHandler.post(new Runnable() { public void run() { mWebView.loadUrl("javascript:wave()"); } }); I get myWebView cannot be resolvedCaner
You also need to pass
mWebView to cunstructor, I didn't see that before.Krzychu
Actually I don't. I found out that myWebView was private and that's why I wasn't able to access it :) Nevertheless I think I will make a subclass (like in the example) because it seems much easier without handlers. Thanks for your help!
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>
========================================================================
1 Comment
MazarD
In this example for api17+ the getPhoneNumber must have the annotation @android.webkit.JavascriptInterface
You can use WebView.addJavascriptInterface function to achieve this. More info: In Google documentation