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(PHP 5 >= 5.1.2)
spl_autoload — Default implementation for __autoload()
This function is intended to be used as a default implementation for __autoload(). If nothing else is specified and spl_autoload_register() is called without any parameters then this functions will be used for any later call to __autoload().
By default it checks all include paths to contain filenames built up by the lowercase class name appended by the filename extensions .inc and .php.
Es wird kein Wert zurückgegeben.
Note this function will LOWERCASE the class names its looking for, dont be confused when it cant find Foo_Bar.php
also, unlike most other autoloader code snippets, this function DOES NOT translate underscores to slashes.
class Foo_Bar {}
will load foo_bar.php and will not try to load foo/bar.php
You can get around this with
spl_autoload_register(function($class) { return spl_autoload(str_replace('_', '/', $class));});
Note, that the default autoload implementation is written in C land and is always slightly faster then your native PHP one.
Here is a trick to use default implementation with any configuration:
<?php
// Your custom class dir
define('CLASS_DIR', 'class/')
// Add your class dir to include path
set_include_path(get_include_path().PATH_SEPARATOR.CLASS_DIR);
// You can use this trick to make autoloader look for commonly used "My.class.php" type filenames
spl_autoload_extensions('.class.php');
// Use default autoload implementation
spl_autoload_register();
?>
This also works with namespaces out of the box. So you can write code like "use My\Name\Object" and it will map to "class/My/Name/Object.class.php" file path!
Note that, the orders of file extensions is important for performance. You should make the priority of your favourite file extension higest or use only one extension for your class files. Check out this example:
Some class files:
ClassA.php
<?php class ClassA { var $val = 'Hello from class "ClassA"'; } ?>
ClassB.php
<?php class ClassB { var $val = 'Hello from class "ClassB"'; } ?>
ClassC.php
<?php class ClassC { var $val = 'Hello from class "ClassC"'; } ?>
ClassD.php
<?php class ClassD { var $val = 'Hello from class "ClassD"'; } ?>
ClassE.php
<?php class ClassE { var $val = 'Hello from class "ClassE"'; } ?>
1. Simple:
<?php
// default priority: .inc .php
for($n=65; $n<70; $n++) {
$className = 'Class'.chr($n);
spl_autoload($className);
$ins = new $className;
echo $ins->val.'<br>';
}
// 4.2 miliseconds
?>
2. Change priority:
<?php
spl_autoload_extensions('.php,.inc');
// new priority: .php .inc
for($n=65; $n<70; $n++) {
$className = 'Class'.chr($n);
spl_autoload($className);
$ins = new $className;
echo $ins->val.'<br>';
}
// 1.4 miliseconds
?>
Or you can use this simple function that runs a bit faster for the extensions with lower priority :)
<?php
function my_autoload($className, $extList='.inc,.php') {
$ext = explode(',',$extList);
foreach($ext as $x) {
$fname = $className.$x;
if(@file_exists($fname)) {
require_once($fname);
return true;
}
}
return false;
}
for($n=65; $n<70; $n++) {
$className = 'Class'.chr($n);
my_autoload($className);
$ins = new $className;
echo $ins->val.'<br>';
}
// 2.6 miliseconds
?>
---
Safak Ozpinar - Istanbul University, Computer Engineering
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