[wp-docs] Validation Error with Plugins Might Need Attention
ringmaster at midnightcircus.com
Wed Mar 9 22:23:54 GMT 2005
Should there be a warning about it in the Plugin pages? Sure, but I
wouldn't make a huge issue of it. As I said, there isn't much cause to
use sessions in WordPress plugins anyway. Add a note to the Writing
Plugins page about it, add some info in a related FAQ about it, move on.
!!!Using PHP Sessions
Please avoid using PHP session statements in your plugins (like
<code>session_start()</code>) because the output that PHP produces for
browsers that don't support cookies will break XHTML validation on a
WordPress site with the plugin activated.
> Does this error cause harm to the site or content? It is just annoying to
> me, but what do I know?
It can cause your site not to validate. If we're predicating getting
theme/CSS assistance in the forums on whether the site's code validates,
then this would be an issue. Otherwise, not much damage is usually
caused by breaking XHTML a little here and there. Usually this
particular issue doesn't break layouts visually, and isn't even detected
until you try to validate the page.
If a user discovers that one of their plugins causes their site to
produce invalid XHTML/HTML output, they should disable that plugin and
email the plugin author about the issue or if the plugin is in the
repository, submit a ticket in the wp-plugins.org issue tracker. This
advice would be the same for any plugin that breaks a site.
> In the article at
> he has a work around, but he calls it dangerous. I wouldn't know dangerous
> workaround if it bit me in a private part. Is it?
Well, the first "workaround" is to disable the offending plugins, which
is just what I suggested. This has an obvious downside, but only the
site operator can determine which is more important, validation or that
The second workaround seems reasonably safe, but it'll most likely have
an odd effect on plugins that rely on sessions and process hits from
browsers that don't accept cookies. He says he only knows of one such
plugin, and he found a replacement for it.
Short answer: No, not dangerous, but the plugin that uses it probably
won't work as expected if you apply this "fix". Better to find a
different plugin that does the same thing or petition the author not to
We've now both written tons more on this issue than what Codex will need
to contain. :)
More information about the wp-docs