Why Not Object Oriented

• There are fewer PHP developers with good OO knownledge
• Its easy to design more complicated systems then needed
• Less experience means a whole new set of mistakes to make

So lets use OO

• Its my workshop and I don't do much straight procedural code
• Things to keep in mind when doing OO Design:
  • Design a Solid API
  • Document you code
  • Each class should do one thing well
  • Keep things simple
  • Avoid constants and Globals when possible
  • Layer your Application
  • Use inheritance but only for a few generations
  • Use Design patterns

Design Patterns

in essence, design patterns are simply "down to earth"; good common sense. A collection of the best solutions to problems that software designers encounter again and again in their daily work. Given a little thought, design patterns are really an expression of the obvious, about which there's not much room for debate Harry Fuecks, phpPatterns

• phpPatterns.com design section

Our Major decisions

• What are the layers of our application ... Maybe
  • Data Access (Model,Data)
  • Control (Controller,Logic)
  • Presentation (View)
• Can we use 3rd Party (Open Source) components for any or part of the layers ... Maybe
  • Data Access:
    • DB_DataObject for a Object Relation Mapping based Data Access
    • PEAR::DB or many others plus a DAO pattern
  • Control:
    • A front controller pattern (You have to bring in an entire framework like Seagull to get one of these)
    • Use a page controller (I don't know of any except QuickForm_Controller but they are easy to write)
  • Presentation:
    • Smarty - own mini language
    • Flexy - multiple own mini languages or just plain php
    • Savant - plain old php

Lets start with the Data Access Layer and then use them to Build models

• I like using DAO if I don't already have a framework that does the gruntwork for OR mapping
• This dao code uses and is based of sample code from phpPatterns
• Our simple Database
• DAO Code:
  • Simple db abstraction for mysql
  • Base DAO Class
  • All sql access to the user table
  • All sql access to the expense table
  • Note that you don't have to use models, you gain many benifits just from using DAO
  • Model Code:
    • User Model
    • Expense Model

A simple front controller that runs page contollers

• Front controller index.php
• User Controller
• Expense Controller

Presentation Layer Using Savant Templates

• Lists Users
• Edit/Add User
• List Expenses
• Edit Expenses

Thanks for coming

Slides and code are online at: http://blog.joshuaeichorn.com/presentations/