GWT Script Injection Failure with PubNub - gwt

Question

New to GWT but I love it so far. I do have a problem that's easy to reproduce. It is a big problem for me because I want to create a GWT Module for PubNub - a utility we use internally.
I created a demo project to test out encapsulation and I have found an interesting problem with ScriptInjector/Pubnub.
At first I followed the PubNub instructions. NOTE: I have included my keys for my test account. Feel free to use them.
Following the instructions I put these two items in the html file in the GWT project (with my keys specified):
<div pub-key="pub-b8b75fbd-c4cf-4583-bab9-424af7a7f755" sub-key="sub-5e843c94-1193-11e2-bba9-b116c93082cf" ssl="off" origin="pubsub.pubnub.com" id="pubnub"></div>
<script src="http://cdn.pubnub.com/pubnub-3.1.min.js"></script>
When I do this, I can use JSNI to access pubnub. It all works great.
What doesn't work is if I delete the tag here and inject the script instead with the following code. I know the script injects because I can see the success message and I can see the script in Developer tools in Chrome.
ScriptInjector.fromUrl("http://cdn.pubnub.com/pubnub-3.1.js").setCallback(
new Callback<Void, Exception>() {
public void onFailure(Exception reason) {
Window.alert("Script load failed.");
}
public void onSuccess(Void result) {
Window.alert("Script load success.");
}
}).inject();
I feel this must be somehow related to accessing the DOM with the delayed script, or because the script is not a part of the DOM. It's trying to access the setup div and it's not able to...(just my guess)
Any thoughts? I need to move the items out of the html file because I need to modularize this project for use in other larger projects. Any help would be appreciated.
(PS, I have tried to create html widgets as well, and add them in EntryPoint. This also adds the tag to the page based on my browsing in Developer Tools in Chrome, but it fails to work just as ScriptInjector fails.)
EDIT: Here is as simple a project as I can make to demo the problem:
html file:
above the closing body tag:
<div pub-key="pub-b8b75fbd-c4cf-4583-bab9-424af7a7f755" sub-key="sub-5e843c94-1193-11e2-bba9-b116c93082cf" ssl="off" origin="pubsub.pubnub.com" id="pubnub"></div>
<script src="http://cdn.pubnub.com/pubnub-3.1.min.js"></script>
<script src="pubnubWrapper.js"></script>
pubnubWrapper.js (basically what's at the pubnub website):
function subToPubNub(){
    PUBNUB.subscribe({
        channel    : "hello_world",      // CONNECT TO THIS CHANNEL.
 
        restore    : false,              // STAY CONNECTED, EVEN WHEN BROWSER IS CLOSED
                                         // OR WHEN PAGE CHANGES.
 
        callback   : function(message) { // RECEIVED A MESSAGE.
            alert(message);
        },
 
        disconnect : function() {        // LOST CONNECTION.
            alert(
                "Connection Lost." +
                "Will auto-reconnect when Online."
            )
        },
 
        reconnect  : function() {        // CONNECTION RESTORED.
            alert("And we're Back!")
        },
 
        connect    : function() {        // CONNECTION ESTABLISHED.
 
            PUBNUB.publish({             // SEND A MESSAGE.
                channel : "hello_world",
                message : "Hi from PubNub."
            })
 
        }
    })
}
ScriptTest.java:
public class ScriptTest implements EntryPoint {
public void onModuleLoad() {
//add a button to sub to pubnub
Button subButton = new Button("Sub");
//add the event handler for button
subButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
//sub to pubnub
callSub();
}
});
RootPanel.get().add(subButton);
}
public native void callSub() /*-{
//call my wrapper to pubnub
$wnd.subToPubNub();
}-*/;
}
This all works as is.
If you remove the pubnub script from the html file and add it with script injector, it fails. If you add the script to the gwt.xml file, it fails.
Any Ideas?

Answer 1

Can you post your JSNI code?
I bet you are accessing PubNub via the $wnd variable right?
If you put the script tags in your module's xml file the pubnub code will be loaded in the host's page window (you can check with Chrome DeveloperTools).
ScriptInjector by default won't load it there but in the GWT namespace.
So in order to load it into the host's window namespace you have to pass the TOP_WINDOW to the ScriptInjector
ScriptInjector.fromUrl("http://cdn.pubnub.com/pubnub-3.1.js").setCallback(
new Callback<Void, Exception>() {
public void onFailure(Exception reason) {
Window.alert("Script load failed.");
}
public void onSuccess(Void result) {
Window.alert("Script load success.");
}
}).setWindow(ScriptInjector.TOP_WINDOW).inject();