Call Java function from JSNI

I'm having trouble with a JSNI calling a Java method:

public static native void update() /*-{
    [email protected]::populate()();
}-*/;

No errors, its just that the method is not getting triggered, the Java method, populate() which shows a alert box when called, is not firing.

MyPage however is a Errai page annotated with @Page

Solution

I think you are miss-understanding the meaning of the instance preceding the @ symbol in JSNI.

You are calling the method populate() of the instance this, but your update() method is static.

You have either define populate() as static and call it in a static way.

package app.client.local;
class MyPage {

  public static native void update() /*-{
    @app.client.local.MyPage::populate()();
  }-*/;

  public static void populate() {
  }
}

Or you can pass the instance of the class having the method as argument to your jsni code:

package app.client.local;

class MyClass {
  public void populate() {
  }
}

class MyPage {
  public static native void update(MyClass instance) /*-{
    [email protected]::populate()();
  }-*/;
}