Blog

PubSubHubbub vs. rssCloud

UPDATE: I’ve written a PubSubHubbub-to-XMPP gateway that solves some of the issues of running a real-time feed reader behind a firewall.

UPDATE 2 rssCloud has a serious vulnerability that needs to be addressed in the protocol. I’ve linked some security recommendations here that rssCloud hubs should implement as soon as possible.

These last few months have brought us not one, but two RSS-to-real-time protocols: PubSubHubbub and rssCloud. While rssCloud has been “around” for a while, it never saw much adoption or interest until recently.

As a developer, the important question is: which of these two protocols should I focus on?

A quieter window.name transport for IE

Using window.name as a transport for cooperative cross-domain communication is a reasonably well-known and well-researched technique. I came across it via two blog posts by members of the GWT community that were using it to submit GWT FormPanels to endpoints on other domains.

Mix's Gestalt project is on the wrong track

I came across the Mix Gestalt project tonight and I thought I’d share some thoughts. It’s a bit of script that effectively sucks code snippets in languages other than Javascript out of your page and converts them to programs running on the .NET platform.

While interesting, it has a number of drawbacks that make it far less interesting than the HTML5-based approach that works in the standards-compliant browsers based on WebKit, Gecko and Opera, as well as the improved IE8.

Disable controls with a CSS-only glass panel

Here’s a neat CSS-only panel that you can use to disable controls within a given <div> element. It uses an absolutely-positioned <div> within the container of controls you’d like to disable. The glass panel is positioned using CSS to overlap the controls, and set partially transparent to give the controls a disabled look.

Note that this only works in standards mode, <!DOCTYPE html>, due to IE’s painfully outdated quirks mode. Additionally, your container of controls needs to be styled as overflow: hidden to work around the limitations of the height expression and position: relative so the parent can become a CSS positioning parent.

@SuppressWarnings on variable declarations

I’ve been using this trick for a while and I thought I’d share it. For those who live by Eclipse’s quickfixes, it’s not entirely obvious that it’s legal.

If you have legacy code like the code below, where foo.list() is a Java 1.4-compatible method returning java.util.List, you’ll normally see an “unchecked cast” warning on the assignment like so:

public void doSomeListStuff(Foo foo) {
    List list = foo.list(); // Warning: unchecked cast
    for (Blah blah : list) {
        frobinate(blah);
    }
}

Normally, Eclipse offers to fix it for you like this: