GWT and Javascript

Question

Unable to call javamethod from javascript in a GWT java class.

Please find the code snippet from below.

package abc;

public class jsclass extends Composite {

public native boolean getOnlineSchedlueResult() /*-{

    function listener(event) {

    //alert("getOnlineScheduleResult called 2 Outside");
     var data = JSON.parse(event.data);
     if(data.FinderSuccess == true){
        parent.onlineMoveNavigation = [email protected]::onlineMoveNavigation()();
     }
  }

  if (parent.addEventListener){
        //alert("parent getOnlineScheduleResult called 3");
        parent.addEventListener("message", listener, false);
        //alert("getOnlineScheduleResult called 3A");
        parent.postMessage("test", "*");
 } else {
        //alert("getOnlineScheduleResult called 4");
        parent.attachEvent("onmessage", listener);
        parent.postMessage("test", "*");
 }

}-*/;

    public void onlineMoveNavigation(){
        GWT.log("onlineMoveNavigation called");
        presenter.moveNavigationNext();
    }

}

A JSNI comment block begins with the exact token /*-{ and ends with the exact token }-*/. It is not a commented code. — Ajay Babu Kunapareddy
– Ajay Babu Kunapareddy, Commented Feb 2, 2015 at 14:06
What is the purpose of parent.onlineMoveNavigation? Is it supposed to store a function or the result of [email protected]::onlineMoveNavigation()()? I'd wager it's the latter case (since onlineMoveNavigation returns void). In which case you want to drop the second pair of parentheses: parent.onlineMoveNavigation = [email protected]::onlineMoveNavigation(); to actually store a reference to the onlineMoveNavigation method in parent.onlineMoveNavigation. — Igor Klimer
– Igor Klimer, Commented Feb 2, 2015 at 22:36

Thomas Broyer · Accepted Answer · 2015-02-02 14:58:58Z

1

The this keyword won't evaluate to your jsclass instance when listener is called by the browser.
You have to bind your jsclass instance to a variable that you can reference from your listener function/closure.

var self = this;

function listener() {
  //alert("getOnlineScheduleResult called 2 Outside");
  var data = JSON.parse(event.data);
  if(data.FinderSuccess == true){
     parent.onlineMoveNavigation = [email protected]::onlineMoveNavigation()();
  }
}

answered Feb 2, 2015 at 14:58

Thomas Broyer

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1 Comment

Ajay Babu Kunapareddy Over a year ago

Thanks thomas. Now it is invoking method onlineMoveNavigation. Appreciate your assistance.

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