Animation in web applications can do more than add pizazz to a page, it can give good visual cues to the user as to what is happening.
For example, consider an image carousel, where you have one largish image and smaller ones in the background.
Having images animate to get larger and move into place (in addition to sliding on and off the screen) lets the user confirm the intended image is being shown.
A co-worker mentioned one day that he was having problems with setting multiple cookies in the same Set-Cookie HTTP header, but things were fine if they were set with separate headers. He noted that it was not consistent across browsers, and that the specs seem to indicate that you can set multiple cookies with a single Set-Cookie header; RFC 2109 confirms that.
The current version of Mobile Safari on the iPhone and iPod touch allow you to do 3D transformations in CSS. This allows you to give objects perspective and rotation in 3D space, as well as the ability to use transitions and animations.
This follow-up to my post about SSL and IP addresses covers using SSL with multiple ports on the same IP address. We often use alternate port numbers to provide test versions of a host or application, since just changing the port number keeps the ServerName the same.
A question came up at the last Web Council Meeting about protecting a directory with Pubcookie. The page loaded, but CSS, Javascript, and images didn’t. This can almost always be fixed by using PubcookieAppID in your .htaccess file.
Web applications for Mobile Safari (used on the iPhone and iPod touch) can take advantage of multiple touches and gestures. The simplest gestures to implement are scaling and rotating an object, since support for them is built-in.
A few weeks ago I wrote about each SSL certificate used on a web server needing to have its own IP address. I ran across a reference to RFC 2817, Upgrading to TLS Within HTTP/1.1. It describes a method to upgrade a connection to TLS (Transport Layer Security, the successor to SSL; I’ll use the terms interchangeably). It’s somewhat complex, and does indeed expand the request/response model along the same lines as basic authentication while taking advantage of HTTP/1.1 persistent connections.
Of course, just because something is described in an RFC doesn’t mean it’s being used. Apache has TLS Upgrade support as of 2.2, but at this time none of the browsers (at least the major ones) support the protocol. Even though it’s not really in use, it’s an interesting exercise to look at how it’s defined and think about implications of its use.
I’m often asked questions about using certificates with SSL-enabled web servers, mostly centered around hosting multiple sites on the same server. Many times my reply starts out as a series of questions to find out what the person is trying to do, who will be using the various servers, and how much the person is willing to spend.
The simplest answer is that each IP address can be associated with only one SSL certificate. There are, however, subtleties depending on the kind of certificate and the intended audience. Before I give an overview of how browsers, web servers, and SSL certificates interact, let me first define how I use various terms, and give a few examples of how we have various servers set up and what the ramifications are.
Update 25-Nov-2008: I’ve written a follow-up post about using TLS Upgrading which would allow multiple SSL certificates on one IP address, but browsers do not support it.
Update 3-Mar-2009: Another follow-up post about using multiple port numbers.
My wife and a developer co-worker were working on a client Plone site the other day when they ran into an anomaly. Melody was checking whether search results showed an icon to indicate pages which should only be available to registered users (using custom code for the site which is different than what normally happens in Plone, private content not showing up at all in the search results). She wasn’t seeing the lock icon, but the developer saw it on his own local copy of the same site. They then proceeded to look for find differences between the two sites.
