Turning a row id into an accessor

Say you want to store configuration data in a database, such as:

Table: preferences ++--++ | id | name             | value                      | ++--++ |  0 | filename         | /path/to/file.txt          | | 1 | item_enabled     | 1                          | | 2 | task_name        | something                  | ++--++

but instead of doing: my $row=DB::Prefs->search({ name => "filename" })->first; print $row->value,$/; $row->value("/new/path/to/file"); you want to set up accessors to point to the row in the database rather than the column: print DB::Prefs->filename,$/; DB::Prefs->filename("/new/path/to/file"); which is much easier to use and looks cleaner.

All you have to do is create your Prefs class with an AUTOLOAD function, as below: package App::Prefs; use base 'App'; use strict; __PACKAGE__->table("preferences"); __PACKAGE__->columns( ALL => qw/ id name value/ ); sub AUTOLOAD { my $self = shift; my $newval = shift; my $attr = our $AUTOLOAD; $attr =~ s/.*:://; return if($attr eq "DESTROY"); my $row = $self->search({ name => "$attr" })->first; if(defined($newval)) { if(!$row) { $row=$self->insert({ name => "$attr" }); }     $row->value($newval); $row->update; }   return defined($row) ? $row->value : undef; }

So calling an accessor with no matching "name" in the preferences table will return "undef", calling an accessor with a parameter will insert that name/value pair into the table, and thereafter calling the accessor will return the correct value for the name matching the accessor.