I found out today about an obscure feature in HTML: server-side image maps. This is an image with an ismap attribute:
<a href="/foo"><img src="bar.png ismap /></a>
Upon clicking on the image, the coordinates are appended to the URL as a query string of the form ?x,y, e.g. /foo?17,42 when clicking 17 pixels from the left and 42 pixels from the top. Note that this is true even if there is already a query string; if the href is /foo?bar, then the request would be /foo?bar?17,42 (see <a> definition in HTML5.2).
This obviously has the potential to generate a ridiculous amount of URLs, but it could in some cases be necessary to correctly recurse through a site.
I'm pretty sure this is extremely rare. Unlike <area>, I don't think I've ever seen ismap before.
This would be tricky to implement because you have to know the image size before you can even generate the URLs.
If implemented, it should probably be disabled by default and enabled through an option due to the potential URL explosion.
Overall, I'm leaning strongly towards HELL NO!, but I found this interesting enough of a case to mention here. If anyone has a real-world example where this would actually be useful (unlike the one above), please do tell.
I found out today about an obscure feature in HTML: server-side image maps. This is an image with an
ismapattribute:Upon clicking on the image, the coordinates are appended to the URL as a query string of the form
?x,y, e.g./foo?17,42when clicking 17 pixels from the left and 42 pixels from the top. Note that this is true even if there is already a query string; if thehrefis/foo?bar, then the request would be/foo?bar?17,42(see<a>definition in HTML5.2).Real-world example using this feature via an ArchiveBot job: http://www.esva.net/cgi-bin/pix?Scrapbooks/Scrapbooks_from_2010/Rally_for_Sanity/rrsf013.jpg (the bar on the left of the picture)
Some thoughts on this:
<area>, I don't think I've ever seenismapbefore.Overall, I'm leaning strongly towards HELL NO!, but I found this interesting enough of a case to mention here. If anyone has a real-world example where this would actually be useful (unlike the one above), please do tell.