How to extract parts of a GWT application into a library of separate dialogs - gwt

Question

I'm trying to extract parts of a GWT application into many separate dialogs that can be invoked from php.
Existing state:
We have a GWT appplication that is deployed to JBoss as a WAR.
The app has a single module with a signle entry point.
The main JSP sets up the environment and then has some JS that loads the .nocache.js using document.write();
The entry point's onModuleLoad() creates a panel to fill the browser and adds it to the root using RootPanel.get("root").add();
When some event happens (e.g., user presses button) we pop up a DialogBox by instatiating a subclass and calling center() or setVisible()
Desired state:
We want a php app with multiple pages, to be able to invoke various DialogBox subclasses.
I think that the php side should use JS function calls that use document.write();
As for the GWT side, the options I see are:
One module with multiple entry points.
Multiple modules.
Does anyone have any experience or understanding of what would be the best practice here?

Answer 1

If I've understood right, you need to call GWT methods from Javascript.
You can use JSNI.
But I think you should try gwt-exporter on the GWT side. Overview. Tutorial.
It's simple GWT module to create JS_API for your GWT modules.
Not pretending to be the best practices, just quick example.
On the server-side you include an existing GWT module with DialogBoxes on every page.
You need to modify this GWT module or create new like this.
public class GwtModule implements EntryPoint {
#Override
public void onModuleLoad() {
// exportable class
DialogBoxManager dbm = new DialogBoxManager();
// export all Exportable classes of module
ExporterUtil.exportAll();
// needed cause JS_API will be available only after the GWT is loaded
onLoad();
}
// call when GWT module loaded
private native void onLoad() /*-{
$wnd.loaded();
}-*/;
DialogBoxManager looks like this
#Export
#ExportPackage("pkg")
public class DialogBoxManager implements ClickHandler, Exportable {
private DialogBox db;
public DialogBoxManager() {
this.db = new DialogBox();
}
#Export("showDB")
public void showDialog() {
db.setVisible(true);
db.center();
db.show();
}
#Override
public void onClick(ClickEvent event) {
showDialog();
}
}
String values in #Export("show"), #ExportPackage("pkg"), etc. annotations will be used in our JS_API calls for annotated GWT methods (you can export also fields).
You can use just #Export (as I did for DialogBoxManager).
When GWT module is loaded in your JS library you can realize initialization of JS_API member or what you need
var dbManager = null;
...
function loaded() {
dbManager = new pkg.DialogBoxManager();
}
and then just call JS_API like this
function showDB() {
if (dbManager != null) {
dbManager.showDB();
}
}