Re: [EP-underground] Questions about subjects

Sounds like $session is not defined.

try:
           my $subj = EPrints::Subject->new( $eprint->get_session, $subj_id );
instead

sorry for the run-around. Coding of the top of my head is kinda tricky.


On Tue, Feb 11, 2003 at 03:03:04 -0600, Alan Schmitz wrote:
> Eventually I figured out that I needed a subject object, and I came up with 
> the code you've listed below.  Now I can get to the screen to add 
> bibliographic information, but I get another error when I hit the "next" 
> button:
> 
>     Can't call method "get_db" on an undefined value at
>     /usr/local/eprints/perl_lib/EPrints/Subject.pm line 172.
> 
> I know the subject ID is valid, because I can print it to STDERR.  The 
> session appears to be blank when I print it to STDERR.  I would expect to 
> see a hash or array reference here.  Where does $session come from, if it's 
> not passed to the set_eprint_automatic_fields function?
> 
> Thanks,
> Alan Schmitz
> 
> -----
> SILO Project Coordinator
> State Library of Iowa
> 
> 
> At 12:35 PM 2/10/2003 +0000, you wrote:
> >oh, my bad!
> >
> >The $subj is an id string, not a subject object
> >
> >change:
> >
> >         foreach my $subj ( @{$searchsubjects} )
> >         {
> >                 $stext .= EPrints::Utils::tree_to_utf8(
> >                                 $subj->render_description )." ";
> >         }
> >to
> >         foreach my $subj_id ( @{$searchsubjects} )
> >         {
> >                 my $subj = EPrints::Subject->new( $session, $subj_id );
> >                 $stext .= EPrints::Utils::tree_to_utf8(
> >                                 $subj->render_description )." ";
> >         }
> >
> >On Sun, Jan 26, 2003 at 04:15:09 -0600, Alan Schmitz wrote:
> > > A couple of months ago I asked a question about subject keyword
> > > searches in E-Prints.  Chris Gutteridge responded with the field
> > > definitions and code below.  I'm finally getting around to implementing
> > > his suggestion which includes using a new text field for subject
> > > keywords.
> > >
> > > The code works until it tries to call the "render_description"
> > > function.  Perl gives the following error, 'Can't call method
> > > "render_description" on unblessed reference'.
> > >
> > > I've also tried to make a new subject object from the subject ID, but I
> > > don't know what I'm supposed to pass for the session parameter.  What
> > > do I need to do so I can call "render_description", or how do I make a
> > > new subject object from a subject ID?
> > >
> > > Thanks,
> > > Alan Schmitz
> > >
> > > ----
> > > SILO Project Coordinator
> > > State Library of Iowa
> > >
> > > > { name => "searchsubjects", type=>"subject", top=>"subjects", multiple
> > > > => 1, browse_link => "subjects" },
> > > >
> > > > { name => "subjectstext", type => "longtext" },
> > > >
> > > > we'd make the following trigger
> > > >
> > > > sub set_eprint_automatic_fields
> > > > {
> > > >     my( $eprint ) = @_;
> > > >     my $searchsubjects = [];
> > > >     my $setall = 0;
> > > >     foreach my $subjid ( $eprint->get_value( "subjects" ) )
> > > >     {
> > > >             push @{$searchsubjects}, $subjid;
> > > >             if( $subjid eq "all" ) # or whatever the key for the ALL 
> > field is
> > > >             {
> > > >                     $setall = 1;
> > > >             }
> > > >     }
> > > >
> > > >     # set ALL the searchsubjects if the flag is set
> > > >     if( $setall )
> > > >     {
> > > >             foreach my $subjid (
> > > >                     "dallas",
> > > >                     "foo",
> > > >                     "baz",
> > > >                     "fnord",
> > > >                     "bar" )
> > > >             {
> > > >                     push @{$searchsubjects}, $subjid;
> > > >             }
> > > >     }
> > > >
> > > >     $eprint->set_value( "searchsubjects", $searchsubjects );
> > > >
> > > >     my $stext = "";
> > > >     foreach my $subj ( @{$searchsubjects} )
> > > >     {
> > > >             $stext .= EPrints::Utils::tree_to_utf8(
> > > >                             $subj->render_description )." ";
> > > >     }
> > > >     $eprint->set_value( "subjectstext", $stext );
> > > > }
> >
> >--
> >
> >  Christopher Gutteridge                   [email protected]
> >  ePrints2 Coder, Support and Stuff        +44 23 8059 4833

-- 

 Christopher Gutteridge                   [email protected]
 ePrints2 Coder, Support and Stuff        +44 23 8059 4833