DevShed has posted the final part of their look at working with the Interpreter pattern and its use in a PHP5 application with the creation of a simple blogging application.

As you can see, the logic that drives the interpreter pattern is rather easy to understand and implement with functional PHP code. Therefore, in this final installment of the series, I'm going to demonstrate how to get the most out of this handy pattern by developing a highly expansible blogging application. The application will be able to insert, update and delete blog entries, using a simple MySQL database as backend.

They start off with the creation of the MySQL class that will interface with the database backend for the application. Also included is a Result class to fetch the results from each query. On top of these, they create the Blog class to handle the requests for information and a BlogHandler class to push the submitted data back into the database.

Finally, they wrap it all together and give a real-life example of it in action, inserting new blog information and making an update of the content on one.