how to call JSNI function from Javascript function?

Question

Here is caller button samples in html:

<input type='button' value='Call' onclick='Test()'>

And here are some functions I tried and which were not worked:

<script type="text/javascript">
    function Test() {
        com.tests.client.Test_GoogleWeb_JSNI::Callee()();
    }
</script>

But we are not able to call Callee().How we can achieve this?I mean how we can invoke JSNI function from javascript?

Help would be appreciated.

Quartersaw

possible duplicate of How to call GWT java function from Javascript? – Larimore

Answer 1

It's very easy. You need to "export" your function written in GWT (or it can be another JSNI) function.

Here is the relevant documentation: http://code.google.com/webtoolkit/doc/latest/DevGuideCodingBasicsJSNI.html#calling

So in your case:

In your GWT code:

public static void Caller() /*-{ 
   ... 
}-*/

public static native void exportStaticMethod() /*-{
   $wnd.Callee =
      $entry(@com.tests.client.Test_GoogleWeb_JSNI::Callee());
}-*/;

Then you call exportStaticMethod() somewhere, even in your onModuleLoad. << YOU MUST DO THIS

Then you can call Callee() from your handwritten javascript code.

Your code for the button:

<input type='button' value='Call' onclick='$wnd.Callee();'>

Settee

Yes i tried but i am not able to invoke the function when we click on the button. – Quartersaw

Have a look I updated my answer to show what the code for your button should be. Also if the function is not being called, I recommend you bring up your browser console (F12 in Chrome) and have a look for any exceptions. – Settee

Answer 2

For chrome, the above solution works if I change onclick='$wnd.Callee() to onclick='window.Callee(). Chrome's browser console tells us $wnd is not defined. $wnd is how to access the browser's window object in JSNI.

Sorry I couldn't just leave this as a comment (not enough points)

Divorcee

Answer 3

See here:

1. Make sure that Test_GoogleWeb_JSNI.Callee() is static.
2. Assign the Callee()-function to the window object.

Genagenappe