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Re: Confusion regarding following a link

From: Bjoern Hoehrmann <derhoermi@gmx.net>
Date: Fri, 20 Apr 2001 09:27:23 +0200
To: "Taha Masood" <taha.masood@streaming-networks.com>
Cc: <http-wg@hplb.hpl.hp.com>
Message-ID: <vdovdt86rm7477bnbsq8aag9cfjfgqasve@4ax.com>
* Taha Masood wrote:
>e.g. I give the following request to a browser:
>http://directory.google.com/Top/Computers/Algorithms/

>Now I render the HTML to my GUI .
>The HTML contains the following link:
>
><a href="/Top/Science/Math/Applications/Communication_Theory/Cryptography/Algorithms/">Cryptography</a>
>
>Now the confusion is that if  my user "clicks" on the
>hyperlink given above , what request should I generate:

Depends on the value of the href attribute of the base element in the
head element :-)

Request URIs must be absolute, either

/Top/Science/Math/Applications/Communication_Theory/Cryptography/Algorithms/

or

http://directory.google.com/Top/Science/Math/Applications/Communication_Theory/Cryptography/Algorithms/

or some non-canonical forms of that URI.

>What I used to do till now was to classify the situation into three portions:
>
>  Whenever we are currently viewing a certain page on the web , and we try 
>  to follow a link to another page , there can be three cases. For all the 
>  cases , the current page is say : www.abc.com/help/u1/myHelp.html

Let's say it's http://www.abc.com/help/u1/myHelp.html

>  FIRST CASE:
>  The link I try to follow is : "/yourHelp.com"
>  Effective URL should be:
>  www.abc.com/help/u1/yourHelp.com

http://www.abc.com/yourHelp.com

>  SECOND CASE:
>  The link I try to follow is : "../../TopLevelHelp.com"
>  Effective URL should be:
>  www.abc.com/TopLevelHelp.com

http://www.abc.com/yourHelp.com

>  THIRD CASE:
>  The link I try to follow is : "www.beta.com/OtherHelp.com"
>  Effective URL should be:
>  www.beta.com/OtherHelp.com

http://www.abc.com/www.beta.com/OtherHelp.com

Please read RFC 2396.

>The problem occurred when I got to the page :
>
>http://directory.google.com/Top/Computers/Algorithms/
>
>The above contains a line in HTML as :
><a href="/Top/Science/Math/Applications/Communication_Theory/Cryptography/Algorithms/">Cryptography</a>
>
>Now when  my user "clicks" on the hyperlink given above,
>according to my CASES , this thing falls into the FIRST CASE,
>and what I do is that the EFFECTIVE URL made is:
>
>http://directory.google.com/Top/Computers/Algorithms/Top/Science/Math/Applications/Communication_Theory/Cryptography/Algorithms/

Nope,
http://directory.google.com/Top/Science/Math/Applications/Communication_Theory/Cryptography/Algorithms/

>I fail to understand what are the General Rules for following links ? What portion of the RFC refers to it ?
>
>I would really appreciate if someone could explain this to me .

Read RFC 2396. If the relative URI (href='...') is an absolute path
href='/...' it completly replaces the old path. RFC 2396 has a lot of
examples on that.

This is no HTTP issue, www-uri@w3.org deals with URIs.

PS: __Please__ wrap your lines after 68 <= x <= 80 characters.
-- 
Björn Höhrmann { mailto:bjoern@hoehrmann.de } http://www.bjoernsworld.de
am Badedeich 7 } Telefon: +49(0)4667/981028 { http://bjoern.hoehrmann.de
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Received on Friday, 20 April 2001 08:27:28 EDT

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