eprints_tech messages

From: Ian Stuart <Ian.Stuart AT ed.ac.uk>
Date: Fri, 26 Sep 2008 09:07:46 +0100

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http://www.eprints.org/tech.php/id/%3CEMEW-k8P97r2160a023399f33d2ee27eb6978bc6b1e-48DC9852.1070207%40ed.ac.uk%3E
*** EPrints community wiki - http://wiki.eprints.org/

Guy Knights wrote:
> Thanks for those links Ian - I appreciate that they provide a lot of
> info related to my issue. However, I'm having a little trouble with 
> the 'parallel authentication routine' script, it says most of the
> code is in a file which they've called 'myCode.pl', in
> archives/ARCHIVEID/cfg/cfg.d/. Where is it specified within EPrints
> that this file should be read and the code executed? The wiki page
> talks about this file, but doesn't explain how EPrints is instructed
> to look at this file. The 'authenticate_user' routine they specify
> goes in this file, but how and when is it executed?
Ah, right.... perhaps this should be added to the page somewhere:

When eprints start, having loaded all it's core modules and code, it 
loads all the (*.pl?) files in the archives/ARCHIVEID/cfg/cfg.d/ and add 
*those* routines into the mod-perl environment.

This is how you can over-ride core eprints code; extend core eprints 
packages (as I do with sub EPrints::DataObj::User::user_with_puid {} in 
http://wiki.eprints.org/w/Add_a_parallel_authentication_routine), or 
just add extra subroutines generally...

So, to get my bespoke authentication handler, I edited sub handler{} in 
perl_lib/EPrints/Apache/Login.pm and added the following code near the top:

              # NEW CODE FRAGMENT
         # Do we have a bespoke authentication routine?
         if( $session->get_repository->can_call( 'authenticate_user' ) )
         {
            return $session->get_repository->call( 'authenticate_user',
                                                    $session, $r );
         }

This looks to see if there is a subroutine 'authenticate_user' (which 
has hopefully been defined in some .pl file in .../cfg/cfg.d ) and 
returns whatever that call returns.
If the routine isn't there, then EPrints just does it's normal 
authentication routines.
[I did it this way so that the concept could be added to the core 
EPrints code :chuckle: ]

The basic process I devised is thus:

   Handler:
     Do we have a current eprints session cookie? (looks in ticket table)
        N - Bounce the user off to get authenticated.
            - user authenticates.
                 - Set an eprints session cookie
                 - Store an identifier on the "new" auth table
            - bounce user back to their original page
        Y - Can we get user from EPrints ticket table?
            Y - Get user details, and log them in
            N - Can we get details from the auth table?
                N - Bounce user over to manual login pages
                Y - Can we get a user based on identifier in auth table
                    N - Bounce user over to manual login pages
                    Y - Create record in ticket table
                        - bounce user to their original page


-- 

Ian Stuart.
Bibliographics and Multimedia Service Delivery team,
EDINA,
The University of Edinburgh.

http://edina.ac.uk/

The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.