Calling javascript function from the android activity - Stack Overflow

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I am using the following code in the main activity , its giving the function display() is not defined

public class cordovaExample extends DroidGap {
    Context mcontext;
    private novel n;
    private Server s;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        new Thread(new Server(this)).start();
        try {
            Thread.sleep(500);
        } catch (InterruptedException e) { }
        new Thread(new Client()).start();

        super.init();

        n = new novel(this, appView); 
        s = new Server(this,appView);

        appView.getSettings().setJavaScriptEnabled(true);
        appView.addJavascriptInterface(n, "novel");
        appView.addJavascriptInterface(s, "Server");

        super.loadUrl("file:///android_asset/www/index.html");
        super.loadUrl("javascript:display()");
    }
}

At the last line it giving the error display() is not defined

function display() {
    alert("abc");
}

Above code shows the display function which is I am using in the html file

Any type of help will be appreciated

I am using the following code in the main activity , its giving the function display() is not defined

public class cordovaExample extends DroidGap {
    Context mcontext;
    private novel n;
    private Server s;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        new Thread(new Server(this)).start();
        try {
            Thread.sleep(500);
        } catch (InterruptedException e) { }
        new Thread(new Client()).start();

        super.init();

        n = new novel(this, appView); 
        s = new Server(this,appView);

        appView.getSettings().setJavaScriptEnabled(true);
        appView.addJavascriptInterface(n, "novel");
        appView.addJavascriptInterface(s, "Server");

        super.loadUrl("file:///android_asset/www/index.html");
        super.loadUrl("javascript:display()");
    }
}

At the last line it giving the error display() is not defined

function display() {
    alert("abc");
}

Above code shows the display function which is I am using in the html file

Any type of help will be appreciated

• javascript
• android
• cordova

Share Improve this question Follow edited Jul 20, 2013 at 9:48 stealthjong 11.1k1414 gold badges4848 silver badges8686 bronze badges asked Sep 20, 2012 at 13:47 akshay1728akshay1728 38322 gold badges66 silver badges1616 bronze badges

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2 Answers 2

Sorted by: Reset to default 6

It's a bad idea to make Cordova load JavaScript on page load. This should be handled by your local JavaScript. Try to call your display() function like this in the HTML page itself:

<script>
    function display()
    {


        alert("abc");


    }

    window.onload = function() {
        display();
    }
</script>

If you need to call a JavaScript from within Cordova at any later point, it is possible to do so this way:

sendJavascript("display();");

To access this method from other classes, you will need to access your main activity. The easy-but-perhaps-unsafe method is to create a static variable in your main Activity that will hold the activity itself. Example:

public class MyActivity extends DroidGap {
    public static MyActivity activity;

    public void onCreate(Bundle savedInstanceState) {
        activity = this;
    }
}

Then, from anywhere in your classes, do:

MyActivity.activity.sendJavascript('display();');

From Cordova 2.6 you can override onMessage in your CordovaActivity (DroidGap), you have to capture the message "onPageFinished", then you can call any function declared on the document:

@Override
public Object onMessage(String id, Object data) {
    if("onPageFinished".equals(id)) {
        sendJavascript("display('abc');");
    }
    return super.onMessage(id, data);
}

And in the HTML:

<script>
    function display(arg) {
        alert(arg);
    }
</script>

Other option is to call it in the onResume() function of the CordovaActivity:

@Override
public void onResume() {
    super.onResume();
    sendJavascript("display('abc');");
}

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