CodingStyle

PEAR Coding Standard

But we're not religious about that...
http://pear.php.net/manual/en/standards.php

Class names reflect directory location

The __autoload stuff only works, if the classname is equal the Directory + Filename.
Therefore the class bx_plugins_foobar has to be placed in _BX_INC_DIR.'bx/plugins/foobar.php' _

(of course, if you include_once the class before you call it, it doesn't matter where the class is. But this approach is not advised in our framework. It makes finding the right classes more difficult)

Static Methods for creating instances of classes

It doesn't make sense every time, so it's not a must, but preferable..

Pro:

Changing of constructor signature possible
Multiple different "constructors" possible
Changeing from singleton to non-singleton or caching (or vice versa) possible

class Penguin {
{panel}
    // only has to be protected, if the constructor really should not be used from outside
    protected function __construct() {
       // do something here
    }
{panel}

    static function getInstance() {
{panel}
        return new Penguin();
    }
{panel}
}

$pingu = Penguin::getInstance();

Minimize public API, seperate API and implementation

use the new PPP functionalityof PHP5

Use Interfaces instead of Abstract Classes

Multiple Interfaces are possible, multiple inheritance isn't

Use interfaces, not classes for type hints

class Penguin implements Fish, Bird {

}

class Icebear implements Mammal {
{panel}
    //NO NO
    function eat (Penguin $food) {
    }
{panel}

    // Better
{panel}
    function eat (Fish $food) {
    }
{panel}
}

It's much more flexible...

Use lowercase fieldnames and tablenames for more compatibility

MDB2 per defaults lowercases everything.
Windows and Macs have case-insensitive table names in MySQL ('cause of filesystem limitations)