Riquez wrote: > Anyway, my question, which is a little off topic i'm afraid, is what > standards are there relating to this?
None that I'm aware of. Headers are part of a protocol-- they are a part of HTTP. Via scripting, you can force your own additional headers[1] or alter ones that get sent back and forth in the http process. even though you CAN place a header AFTER content is sent, 1 of two things will happen. A- the outputted html will simply get ignored, and then a re-direct will occur, for example, and if you're on a fast connection, you'll never see the inbetween. B- the header after the content fails and kills the page. For example, if you start printing an html page, and then send a header for image/jpeg or another format, it won't know what to do, because its already been sent to the browser as text/html. This could either crash the browser, or pop up errors. > Can anyone point me to a site that can explain why headers should not > be sent twice, or indeed if it is OK to, if the server set up allows it? simply put, you can't Logically send headers twice. it would be like writing a business letter on your companies letterhead, and half way down the page, a different companies letterhead appears. It would confuse the reader-- what company is this from? And you'd end up throwing it out. The browser does the same thing. > Does the w3c comment on this? Not that i'm aware of. I'm not even certain that the w3 has authority over a protocol anyway. HTML/SGML and so on are LANGUAGES, not PROTOCOLS. I guess at best, IEEE [2] is the closest governing body over things like this. [1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html -AND- http://www.cs.tut.fi/~jkorpela/http.html [2] http://standards.ieee.org/ Community email addresses: Post message: [email protected] Subscribe: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED] Shortcut URL to this page: http://groups.yahoo.com/group/php-list Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/php-list/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
