Re: getting case count via PSPP::Perl

[Rob Messer]

John,

Ok, that is good to know.  So I guess consider this a feature request to add 
that to some future release.  If the method sometimes returns undef because the 
file header doesn't have the info that then is reasonable enough, but at least 
we could show progress in most cases.  Thank you,

Rob

On May 22, 2011, at 1:20 AM, John Darrington wrote:

> It should be very straightforward.   Most .sav files contain a header field 
> indicating the number of cases.  However, occasionally we've encountered files
> which don't have this field.  So the perl program would have to be prepared to
> handle this case.
> 
> J'
> 
> On Fri, May 20, 2011 at 11:16:26AM -0700, Rob Messer wrote:
>     We have been using the PSPP::Perl interface to read data from .sav files 
> into our database, and it works very well for that purpose.
> 
>     Sometimes the files we read are rather large, and so it takes some time 
> to load the data.  We like to be able to show progress to the user who is 
> loading their data, so we need to know the total number of records to be 
> loaded.  But right now, there doesn't appear to be any way to get the total 
> number of cases other than scanning through all the records.  Is there any 
> way to add a method to the Perl API so that we could do something like this:
> 
>     my $pspp = PSPP::Reader->open($file);
>     my $case_count = $pspp->get_num_cases(); 
> 
>     # then load cases to database and show percent complete at various 
> points...
> 
> 
>     Thanks,
> 
>     Rob
>