Resolve Relative URLs

cvr@sbu.ac.uk
Sat, 16 Mar 1996 12:44:14 CST

From: cvr@sbu.ac.uk
Message-Id: <314B0C01-00000001@rock123>
Date: Sat, 16 Mar 1996 12:44:14 CST
Subject: Resolve Relative URLs
To: fielding@ics.uci.edu

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=============================== Original Message follows ======================

Hello!

I have a problem concerning resolving relative URLs in HTML documents
served up by Web Servers in response to clicks on ISMAP images. I have
studied the RFCs: 1808 and the Draft HTTP/1.0 standard but found no
answer to my problem. I'd appreciate if you could suggest what should
be done correctly in the framework of web.

Problem Description:
-----------------------------
1. We have a page on our web site with the following structure:

/A/mypage.htm
/B/
test.map
test.gif
x.gif

( i.e. B is subdirectory of A and the files: test.map, test.gif and
x.gif are in B ).

2. mypage.htm has an inline image x.gif, and an active ( ISMAP ) image
test.gif refering to the test.map file; all these files are in the
subdirectory B and are referred to using relative URLs in mypage.htm as
illustrated below:

<IMG SRC="B/x.gif" ALIGN=BOTTOM><BR>
<A HREF="B/test.map">
<IMG SRC="B/test.gif" ISMAP ALIGN=BOTTOM></a>

3. TEST.MAP has the following information ( NCSA format ):
default /homepage.htm
rectangle mypage.htm 1,1 235,210

4. I loaded the page in my browser ( I have used different browsers
including NetScape, Microsoft, and Frontier's SHA ):
http://myhost/A/mypage.htm

The page appears fine. I click on the image ( the click gets sent to
the server as: "http://myhost/A/B/test.map?50,100", browser gets back
mypage.htm fine but it CANNOT GET ANY OF THE INLINE IMAGES ( x.gif or
test.gif ).

5. I checked the HTTP headers sent by the Server and they contain a
Location header as :

Location: http://myhost/A/mypage.htm\r\n

This must have properly indicated the base URL to the browser (
according to HTTP/1.0 Spec ) so it could further resolve inline images
relative to "/A"; after receiving the "mypage.htm", apparently, the
browser is trying to get the inline images from "/A/B".

I had the Server sent <WWW-Base: href="http://myhost/A/mypage.htm" >
but it didn't help.

>From this rather verbose description of the problem, could you please
tell me who is at fault ( the browser or server ). I know for sure that
if the Server redirects the browser always it works fine, but then this
not only incurs overhead and additional authentication from the user
( in case the pages are password protected ).

Thanks for your time and I'd very much appreciate all your answers.

/cvr

CVR Murthy
Engineering Tel: 414 - 241 4555 ( W )
Frontier Technologies Corp. 414 - 352 6117 ( H )
10201 N. Port Washington Road E-mail: cvr@FrontierTech.Com.
Mequon, WI 53092.
WEB: http://www.FrontierTech.Com