Adding a new Method to a Package

• You wish that $dbh supported a myquery method

• Subclassing is a pain in the butt

  • You may have to change a bunch of code

• Cheap solution:

         sub DBI::db::myquery {
           my $dbh = shift;
           # Just stick the method here
           return @all_data;
         }

• Now you can say

          @list_of_hashes = $dbh->myquery(...);

• myquery is inherited by DBI's subclasses just the way you'd want.

• Downside: The programmer in the next cubicle might do the same thing

• If you add a lot of new methods, consider making a subclass

• Another downside: People from those other languages may be appalled

continued...

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Copyright © 2003 M. J. Dominus