A co-worker had a problem with using SetEnv and SetEnvIf in his Apache configuration, where the SetEnvIf didn’t seem to be working. What he was running into was the fact that those two commands are implemented in separate Apache modules which happen to run in different request phases.
CSS3 transforms are powerful and are relatively straightforward to use. However, care must be taken when you apply more than one transform. This post isn’t a tutorial on using transforms, but concentrates on how transforms behave when combined. More information is available in the 2D Transforms Working Draft.
Using the text-decoration: underline CSS property is pretty straightforward, as long as you pay attention to how you do so. This post will cover various reasons why underlining may not work as you would think at first.
Many designs call for centering content, either vertically or horizontally. It’s pretty straightforward to center horizontally, but if you wish to support Internet Explorer 7 and earlier, it takes a bit more work to center vertically.
jQuery’s tab widget makes it easy to create a set of tabbed sections which can be swapped for one another. At the same time, they can be configured to gracefully fall back if Javascript is disabled.
CSS2 says that the visibility property can take one of three values: visible, hidden, and collapse. There are many examples of the first two, but I don’t see visibility: collapse very often. Not surprisingly, support for it is spotty and not consistent across the various browsers.
This post compares visibility: hidden, visibility: collapse, and display: none as interpreted by Firefox 3.6 (representative of Gecko-based browsers), Safari 4.0 (representative of Webkit-based browsers), Opera 10.10, and Internet Explorer 8.0 (with Compatibility View disabled). Update 3/23/2011: The newest versions of Firefox (4.0), Safari (5.0), and Opera (11.0) exhibit no change in behavior.
Floats are a powerful feature of CSS and for the most part are pretty straightforward to use.
However, there are many subtleties about them which can cause people to wonder why, for example, images aren’t correctly positioned.
Usually the quickest solution is to throw a bunch of clear: both CSS rules either onto objects or onto empty divs.
This post goes into some of the details about how floats are implemented and how to use them.
How the various browsers’ float implementations differ will also be discussed, but for the most part the latest versions of the browsers all do a good job of agreeing with how to implement the specifications.
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.
There are several methods you can use to create odd/even stripes for lists to make them easier to scan. A List Apart had an article about creating stripes, but being over five years old, it understandably doesn’t cover some newer techniques which are available. Then again, the need to support legacy browsers makes the article more relevant than you would think at first.
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.
