Using PHP Generic Objects To Organize Your Code

Hi, David

(please excuse my bad english speech)

It’s a very good aproach.

I like to use magic functions like __call() in one class called persistence and extend the others, because i use much get and set for organization and encapsulation porpouses.

function __call($method, $args) {
$atributo = strtolower(substr($method, 3, 1)).substr($method, 4);
switch (substr($method, 0, 3)) {
case “get”: return $this->{$atributo}; break;
case “set”: $this->{$atributo} = $args[0];
}
}

this work for generic too. Ex:
class person extends persistence {
/* No code here */
}
$person = new person();
$person->setName(‘David’);
$person->setAge(‘24′);
$person->setOccupation(‘Programmer’);
echo $person->getName(); /* etc */

The persistence have too methods for save, delete, contruct load and other things. So this is possible:

$person = new person(1);
$person->setAge(25) /* Next Year :-D */
$person->save();
$person->delete(); /* No more David :-( */

OBS: Please, how to you make the code PHP look so good?

why don’t you use php’s array functions in load and unload? you can completely avoid your foreach loops using _faster_ builtin functions. or are those loops just for illustration purpose?

using PDO you can generate the object with the fetch method

http://br.php.net/manual/en/function.PDOStatement-setFetchMode.php

What benefits do these generic objects have over associative arrays?

Is this done simply for the OO feel? How is the maintainability improved?

$state_of_mind['me'] = ‘confused’;

;)

Assuming you want to use php5, why not take what Gevã suggests and take it a step further to make things even easier (IMHO)? Instead of using __call(), use __set() and __get() like this:

…
function __get($key) { return $this->vars[ $key ]; }
function __set($key,$value) { $this->vars[ $key ] = $value; }
…

Then you can do something like this:

$person = new generic();
$person->Name = ‘David’;
$person->Age = ‘24′;
echo $person->Name,’ is ‘,$person->Age,”;

Much cleaner and, more importantly, less typing :)

I use this code to append default values to my objects.

function append_default(&$obj)
{
$default = func_get_arg(1);
for($i = 2, $total = func_num_args(); $i < $total; $i++)
$obj->{func_get_arg($i)} = $default;
}

You can call this code like

append_default($some_object,”-”,”name”,”age”);

and the object will have name and age member variables set

Under PHP5 this generic class is a perfect candidate for implementing the Iterator interfase:

http://en.wikipedia.org/wiki/Iterator#PHP

IMHO, your class is too “generic” :)

Seems to be an excuse to use OOP.

I use Objects whenever I feel it is necessary, but I remind myself that every tool has its purpose. I wouldn’t use your class everywhere like you seem to be doing. I would use an ORM: something like Propel or Doctrine or even DB_DataObject (PEAR) or PDO for handling data from an SQL. I would use a class like PEAR’s Config for site-wide variables. I try to avoid re-inventing the wheel and I use stuff that already exists as much as possible.

Your code is very clean and almost perfectly consistent in its format. I like that :) Your braces in your ctor should follow the same format as your other methods.

You should use an existing documentation format like phpDocumentor to automatically generate API docs.

I agree with the others about using magic functions if you would be working in a PHP5 only environment.

Thank you for sharing your thoughts with us. :)

I code only in PHP5 so I don’t know for earlier version, but you could simply do:

$person = (object) null; // or $person = new stdClass();
$person->name = “Marc”;
$person->age = “28″;
echo $person->age;

Hey Dave! Nice class you have there! Did not think about this option before. But anyways, there is a big ‘error’ (if I can call it like that) which I like to point to. It’s not in the code, rather ‘visual’. After the heading “Database Usage” the whole content get’s bold, up to here! Dunno why, but it looks REALLY ugly! Hope you’ll fix that for others :-).

David, thanks for sharing this. I just started learning about OOP and this class really helps. Simple and seems practical.

Anyway, some questions to ask (maybe other ppl can also help)

Will you use this generic class as a class for other classes to inherit/extend?
What about retrieving mulitple records (will it be array in array) in vars?

I’m thinking of using the class for mainly data retrieving/manipulation from database.

Thanks in advance.

You could alse do:

function puts($s) {
print $s . “\n”;
}

class Object {
function __construct() {
$a = array_shift( func_get_args() );
foreach($a as $key => $value) {
$this->{$key} = $value;
}
}
}
$o = new Object(array( “name” => “John Doe”, “age” => 31) );
puts($o->name);
puts($o->age);