Developer.com has posted the next part in their series covering object oriented programming in PHP5, this time focusing on using delegation to enhance the functionality of their prexisting DBQuery class.
At present our DBQuery object simply mimics (all be it - rather simply) a stored procedure. Once executed a result resource is returned which you must store and pass the MySqlDB object if you wish to use functions such as num_rows() or fetch_row() on the result set. Would it not be nice if the DBQuery object were able to implement the functions which the MySqlDB object implements; that are designed to work on the result of an executed query?
They explain each step of the way, giving you the code you'll need to attach to the current working script, making this delegation possible. They look briefly at tpye hinting and simple exception handling in the script before hitting you with a full-blown Exception handler class to improve your script's reliability.
