note 102617 added to language.oop5.patterns
| From: | patrick at bierans dot de | Date: | Thu, 24 Feb 2011 18:42:58 +0000 |
| Subject: | note 102617 added to language.oop5.patterns | ||
| Groups: | php.notes | ||
| Request: | Send a blank email to php-notes+get-177300@lists.php.net to get a copy of this message | ||
It is possible to use every class
as if it is a singleton with a little abstraction.
I wrote some code to show you:
<?php
class MyEngine{ /* static */
static $singletons=array();
static function singletonizer($classname,$classarguments=array()){
$sca=serialize($classarguments);
if (!isset(MyEngine::$singletons[$classname][$sca])) {
if (!class_exists($classname))
/* auto loader, add error reporting for missing classes etc */
include("classes/".$classname."/.class.php");
MyEngine::$singletons[$classname][$sca]
=& new $classname($classarguments);
}
/* this is the pointer/reference and not a new object! */
return MyEngine::$singletons[$classname][serialize($classarguments)];
}
static function debug($msg,$data=""){
echo
"<pre>".$msg."\t".print_r($data,1)."</pre>\r\n";
}
}
?>
Now let's test it!
Defining a class:
<?php
class testclass{
private $value;
function __construct($args){
MyEngine::debug("- testclass contructed with ",$args);
if (isset($args["value"]))
$this->set($args["value"]);
else
$this->value=0;
}
public function set($value){
$this->value = $value;
MyEngine::debug("- testclass set value =",$this->value);
}
public function get(){
MyEngine::debug("- testclass get value =",$this->value);
return $this->value;
}
}
?>
And here we run a testcase:
<?php
$args=array("value"=>12);
MyEngine::debug('create $a','expecting: contruct and set 12');
$a=MyEngine::singletonizer("testclass",$args);
$a->set(13);
MyEngine::debug('create $b','expecting: just load it. should be 13, no
contruct');
$b=MyEngine::singletonizer("testclass",$args);
MyEngine::debug("b value is (expecting 13)",$b->get());
$args=array("value"=>11);
MyEngine::debug('create $c','different args -> new construct, set 11');
$c=MyEngine::singletonizer("testclass",$args);
MyEngine::debug("c value is (expecting 11)",$c->get());
$args=array("value"=>12);
MyEngine::debug('create $d','recognize args, load it, should be 13');
$d=MyEngine::singletonizer("testclass",$args);
MyEngine::debug("d value is (expecting 13)",$d->get());
?>
feedback welcome!
HTH :)
Patrick from Berlin, Germany
----
Server IP: 69.147.83.197
Probable Submitter: 91.66.250.220
----
Manual Page -- http://www.php.net/manual/en/language.oop5.patterns.php
Edit -- https://master.php.net/note/edit/102617
Del: integrated -- https://master.php.net/note/delete/102617/integrated
Del: useless -- https://master.php.net/note/delete/102617/useless
Del: bad code -- https://master.php.net/note/delete/102617/bad+code
Del: spam -- https://master.php.net/note/delete/102617/spam
Del: non-english -- https://master.php.net/note/delete/102617/non-english
Del: in docs -- https://master.php.net/note/delete/102617/in+docs
Del: other reasons-- https://master.php.net/note/delete/102617
Reject -- https://master.php.net/note/reject/102617
Search -- https://master.php.net/manage/user-notes.php