W3C error validating - Bad value for attribute href on element a: Illegal character in query: not a URL code point

Question

I get the bad value for attribute href on element a: Illegal character in query: not a URL code point on W3C with the following a tag:

<a href="/edit_booking.php?requestID=84&amp;moduleID=109&amp;no_rooms=2&amp;parks=Central,East&amp;rooms=1,39&amp;weeks=1,3,5,7,9,11,13,15&amp;day=1&amp;semester=1&amp;start_time=09:00&amp;end_time=10:00&amp;length=1&amp;students=100&amp;type=Lecture&amp;Priority=N&amp;metaID=&amp;comments=Crappy Booking&amp;status=1&amp;round=1&amp;date_submitted=2015-02-16 05:01:17&amp;year=2015/2016&amp;" title="This is a link edit the booking"><i class="fa fa-edit"></i></a>

The link is generated from PHP; now if the commas are not allowed I can do a replace but I'm not sure if they are allowed in this format or not.

Is there something I'm missing, because it looks fine to me?

Answer 1

The spaces in the query string are causing the error. In your sample they appear in two places: comments=Crappy Booking and date_submitted=2015-02-16 05:01:17.

URL-encoding the spaces to %20, as advised by the validator, allows your markup to validate:

<a href="/edit_booking.php? ... &amp;comments=Crappy%20Booking&amp;status=1&amp;round=1&amp;date_submitted=2015-02-16%2005:01:17&amp;year=2015/2016&amp;" title="This is a link edit the booking"><i class="fa fa-edit"></i></a>

Answer 2

Using PHP, rawurlencode will do the job (percent-encoding) for you.

A space will be encoded to %20 (RFC 3986).