Sort::SQL(3)

NAME
Sort::SQL - manipulate SQL sort strings

SYNOPSIS
  use Sort::SQL;

  my $array_of_arrays = Sort::SQL->parse('foo ASC bar DESC bing');
  # $array_of_arrays == [ [ 'foo', 'ASC' ], [ 'bar', 'DESC' ], [ 'bing', 'ASC' ] ]

  my $array_of_hashes = Sort::SQL->string2array('foo asc bar DESC bing');
  # $array_of_hashes == [ { foo => 'ASC' }, { bar => 'DESC' }, { bing  => 'ASC' } ]

DESCRIPTION
Sort::SQL is so simple it almost doesn't deserve to be on CPAN. But since I kept finding myself copy/pasting this method into multiple places, I finally figured it deserved to live in its own class.

METHODS
Sort::SQL implements these methods, each of which take a scalar string of the SQL "ORDER BY" syntax and return a data structure.

  parse( sql sort string )
Returns sql sort string as an arrayref of arrayrefs.

  string2array( sql sort string )
Returns sql sort string as an arrayref of hashrefs. This is for backwards compat only -- parse() is a little faster and more usable.

EXAMPLE
Here's how I use it in my web applications. I want to allow users to re-sort search results by table column header. Each column name is a link back to the server, and I want to provide the SQL "ORDER BY" value as a param in the URI.

In my controller code I do:

 my $sort_order = $c->request->param('order');
 $c->stash->{search}->{order} = Sort::SQL->parse( $sort_order );

And then in my template:

 column.links = {};

 FOREACH pair IN search.order;

  column     = pair.0;
  direction  = pair.1;

  # toggle the sort direction for current sorted column
  # so the next browser request will reverse the sort
  IF ( direction == 'ASC' );
    column.links.$column.direction = 'DESC';

  ELSE;
    column.links.$column.direction = 'ASC';

  END;

 END;

SEE ALSO
SWISH::API::Object

AUTHOR
Peter Karman, <perl@peknet.com>

Thanks to Atomic Learning for sponsoring the development of this module.

COPYRIGHT AND LICENSE
Copyright (C) 2007 by Peter Karman

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.7 or, at your option, any later version of Perl 5 you may have available.