With the help of one of my customers, I have discovered that the code which we use in this plugin, is not compatible with valid XHTML (i.e. XHTML doesn't validate if YouTube video is included in the post).
This all is because
<embed> is not included in XHTML definitions list.
I've searched in Google and discovered there is no solution currently for such Flash or YouTube XHTML code. There is the most wide-known solution called "
Flash Satay" by Drew McLellan, the author of Dreamweaver MX Web Development. Even 2 years after this article release, on his personal site Drew
confirms there is still no solution to get it work in all browsers correctly.
The "Satay" method is amiss. "
While every other browser was getting it right, IE/Windows was not streaming it was waiting for the entire movie to download before playing it. This is fine for small movies, but for anything serious, the lack of streaming is unacceptable." I must say it is specially unacceptable for dynamicly generated forum pages.
Drew offers a workaround on this, proposing to refer to the additional .swf file from which to call an originating swf. Unfortunatelly I doubt it will work for the flash file with the parameters not known before; and it most probably won't work for YouTube content.
If you read the comments for the article on allinthehead.com, you'll notice there are mentioned 3rd party solutions, which use heavy JavaScript and a lot of additional code to embed Flash in XHTML, like
FLACCESS or
FlashObject, but they all are not reliable in the term of pasting YouTube videos I suppose. They all are TOO COMPLICATED solutions for a simple BB code, and I doubt it is necessary to pay attention to them in such easy miniBB solution.
I would prefer to wait a bit and see how browsers' developers will work on it - if it will be requested, I think, it will be fixed by default. Until that it looks not reliable, specially for the dynamically generated content.
So if you install/use YouTube addon we're offering in this thread, please note it will work correctly in all major browsers, but it won't be XHTML valid. I doubt the complicated solution is needed just for this task.