Re: [Openinteract-dev] Using '&' as parameter separator

[Swen T. <swe...@te...>]

On Tue, Mar 25, 2003 at 10:41:53AM -0500, Chris Winters wrote:
> 
> This is one of those issues that I was too lazy to research and 
> went with what worked. Do GET parsing engines regard a lone '&' 
> as an error? Do '&' and ';' work with everything?

Hmm. I do not know what you mean with "GET parsing engines". The problem
is, that you have to make a distinction between HTTP and HTML here. The 
HTTP protocol defines '&' as the parameter separator. Since HTML is an
SGML dialect or instance, the & has to be encoded in HTML as &, because
& is special in SGML (and XML), it starts an entity (as ö or &oring; etc.).
So in HTML you have to write something like <a href="blah?b=1&amp;c=3">...
The browser then decodes the entity &amp; to & and uses this in the GET request
for HTTP:
GET blah?b=1&c=3 HTTP/1.0

A problem arises, when you want to do a redirect. If you have for example a
library method redirect($url), which does not decode the entities, then
you must not use &amp; in the URL, you have to use &

Most browsers allow you to use & in URLs, so you normally will get away with this,
but this will not be the case for XHTML, which has to be wellformed XML.

My guts feeling is, that ';' as separator might not work with every HTTP server,
but I do not really know this.

Hope this helps.

Greetings, Swen