Question

I have a weird problem with deferred binding. I have defined the following module:

<?xml version="1.0" encoding="UTF-8"?>

<!-- Defines the usercategory property and its provider function. -->
<module>

    <define-property name="usercategory" values="c00,c01,c02" />
    <collapse-property name="usercategory" values="*" />

    <property-provider name="usercategory"><![CDATA[
        // Look for the usercategory cookie
        var cs = document.cookie.split(';');
        for (var i = 0; i < cs.length; i++) {
            var name = cs[i].substr(0, cs[i].indexOf("="));
            var value = cs[i].substr(cs[i].indexOf("=") + 1);
            name = name.replace(/^\s+|\s+$/g,"");
            if (name == "usercategory") {
                return unescape(value);
            }
        }

        return "c00";
    ]]></property-provider>

</module>

which sets the property usercategory by looking at the value of a cookie named usercategory.

I use this property application.gwt.xml to defer binding of some classes, for example:

<inherits name="com.example.UserCategory"/>

<replace-with class="com.example.client.ui.menu.MainMenuView01">
  <when-type-is class="com.example.client.ui.menu.MainMenuView"/>
  <when-property-is name="usercategory" value="c01"/>
</replace-with>

This works like a charm when I’m in development mode (i.e. when running my app from within Eclipse). However, if I compile the app and deploy it (in Jetty, but I don’t this this is the problem), then deferred binding does not seem to work, and the expected classes are not loaded. I’ve checked and the cookie is set up properly with the correct value c01, but class com.example.client.ui.menu.MainMenuView01 is not loaded.

Am I missing something? Am I doing something wrong?

Thank you in advance!

Answer 1

I figured out what the problem was, and I’m writing it here in case others might be interested.

The module that I defined (see code in my question) defines a property whose value is taken from a cookie, that is generated after the user logs in the application.

Originally I had a GWT Place for the login, and when the user successfully authenticated the application moved to another Place. In this case when the user enter the application, and the GWT Javascript is downloaded to the browser, the cookie is not set yet (because the user has not performed login yet). Therefore the deferred binding does not work, and the expected classes (like com.example.client.ui.menu.MainMenuView01) are not loaded.

I have no idea why this works correctly when run in development mode. Anyway. the solution that I implemented is to move the login phase outside of the GWT application, and when the login is successful, I add the cookie and the redirect the user to the actual GWT application.