This post introduces some considerations and techniques for handling images within WordPress. This is particularly useful if you are building a website that will be handed over to a client who will then maintain the content with no further involvement from you, the developer.
You would expect identical SQL queries, running against the same database at the same time to give the same results, right? Well, it turns out that such an impossibility can occur. Alas, this wasn’t some easter egg or heisenbug hidden in MySQL, the issue turned out to be perfectly sane. This is how the confusion unfolded…
CSS offers various units for sizing elements. The popular choices are px, %, pt, em and more recently rem. There are two other units that have quickly become favourites of mine, vw and vh. These are relative units, but unlike say em and rem which are relative to the font size of the current and root element respectively, vw and vh are relative to the viewport. A single viewport unit is equivalent to 1% of the viewport width (vw) or height (vh).
A couple of the recent projects I’ve worked on have both had similar stylesheet problems. They have both misused the tilde selector, which has gone unnoticed and been the cause of numerous bouts of CSS bloat. You may well have come across this selector before. After all it’s a selector that’s been in the CSS spec for a long time, even IE7 supports it. Its purpose is to select all matching adjacent siblings.
A project I worked on in some of my spare time back in Summer 2015 was to look for unusual HTTP headers. Things like X-Clacks-Overhead:GNU Terry Pratchett, or ancient use of PICS-label headers. I recently revisited the project and put it online as popular-headers.