If you like to declare an __autoload function within a namespace or class, use the spl_autoload_register() function to register it and it will work fine.
FAQ: things you need to know about namespaces
Using namespaces: fallback to global function/constant
[edit] Last updated: Fri, 26 Apr 2013
Using namespaces: fallback to global function/constant
[edit] Last updated: Fri, 26 Apr 2013
Name resolution rules
(PHP 5 >= 5.3.0)
For the purposes of these resolution rules, here are some important definitions:
-
Namespace name definitions
- Unqualified name
-
This is an identifier without a namespace separator, such as Foo
- Qualified name
-
This is an identifier with a namespace separator, such as Foo\Bar
- Fully qualified name
-
This is an identifier with a namespace separator that begins with a namespace separator, such as \Foo\Bar. The namespace \Foo is also a fully qualified name.
Names are resolved following these resolution rules:
- Calls to fully qualified functions, classes or constants are resolved at compile-time. For instance new \A\B resolves to class A\B.
- All unqualified and qualified names (not fully qualified names) are translated during compilation according to current import rules. For example, if the namespace A\B\C is imported as C, a call to C\D\e() is translated to A\B\C\D\e().
- Inside a namespace, all qualified names not translated according to import rules have the current namespace prepended. For example, if a call to C\D\e() is performed within namespace A\B, it is translated to A\B\C\D\e().
- Unqualified class names are translated during compilation according to current import rules (full name substituted for short imported name). In example, if the namespace A\B\C is imported as C, new C() is translated to new A\B\C().
-
Inside namespace (say A\B), calls to unqualified functions are resolved at run-time.
Here is how a
call to function foo() is resolved:
- It looks for a function from the current namespace: A\B\foo().
- It tries to find and call the global function foo().
-
Inside namespace (say A\B), calls to unqualified or qualified
class names (not fully qualified class names)
are resolved at run-time. Here is how a call to
new C() or new D\E() is resolved.
For new C():
- It looks for a class from the current namespace: A\B\C.
- It attempts to autoload A\B\C.
- It looks for a class by prepending the current namespace: A\B\D\E.
- It attempts to autoload A\B\D\E.
Example #1 Name resolutions illustrated
<?php
namespace A;
use B\D, C\E as F;
// function calls
foo(); // first tries to call "foo" defined in namespace "A"
// then calls global function "foo"
\foo(); // calls function "foo" defined in global scope
my\foo(); // calls function "foo" defined in namespace "A\my"
F(); // first tries to call "F" defined in namespace "A"
// then calls global function "F"
// class references
new B(); // creates object of class "B" defined in namespace "A"
// if not found, it tries to autoload class "A\B"
new D(); // using import rules, creates object of class "D" defined in namespace "B"
// if not found, it tries to autoload class "B\D"
new F(); // using import rules, creates object of class "E" defined in namespace "C"
// if not found, it tries to autoload class "C\E"
new \B(); // creates object of class "B" defined in global scope
// if not found, it tries to autoload class "B"
new \D(); // creates object of class "D" defined in global scope
// if not found, it tries to autoload class "D"
new \F(); // creates object of class "F" defined in global scope
// if not found, it tries to autoload class "F"
// static methods/namespace functions from another namespace
B\foo(); // calls function "foo" from namespace "A\B"
B::foo(); // calls method "foo" of class "B" defined in namespace "A"
// if class "A\B" not found, it tries to autoload class "A\B"
D::foo(); // using import rules, calls method "foo" of class "D" defined in namespace "B"
// if class "B\D" not found, it tries to autoload class "B\D"
\B\foo(); // calls function "foo" from namespace "B"
\B::foo(); // calls method "foo" of class "B" from global scope
// if class "B" not found, it tries to autoload class "B"
// static methods/namespace functions of current namespace
A\B::foo(); // calls method "foo" of class "B" from namespace "A\A"
// if class "A\A\B" not found, it tries to autoload class "A\A\B"
\A\B::foo(); // calls method "foo" of class "B" from namespace "A"
// if class "A\B" not found, it tries to autoload class "A\B"
?>
FAQ: things you need to know about namespaces
Using namespaces: fallback to global function/constant
[edit] Last updated: Fri, 26 Apr 2013
Using namespaces: fallback to global function/constant
[edit] Last updated: Fri, 26 Apr 2013
add a note
User Contributed Notes
Name resolution rules - [5 notes]
kdimi ¶
2 years ago
rangel ¶
3 years ago
The term "autoload" mentioned here shall not be confused with __autoload function to autoload objects. Regarding the __autoload and namespaces' resolution I'd like to share the following experience:
->Say you have the following directory structure:
- root
| - loader.php
| - ns
| - foo.php
->foo.php
<?php
namespace ns;
class foo
{
public $say;
public function __construct()
{
$this->say = "bar";
}
}
?>
-> loader.php
<?php
//GLOBAL SPACE <--
function __autoload($c)
{
require_once $c . ".php";
}
class foo extends ns\foo // ns\foo is loaded here
{
public function __construct()
{
parent::__construct();
echo "<br />foo" . $this->say;
}
}
$a = new ns\foo(); // ns\foo also loads ns/foo.php just fine here.
echo $a->say; // prints bar as expected.
$b = new foo; // prints foobar just fine.
?>
If you keep your directory/file matching namespace/class consistence the object __autoload works fine.
But... if you try to give loader.php a namespace you'll obviously get fatal errors.
My sample is just 1 level dir, but I've tested with a very complex and deeper structure. Hope anybody finds this useful.
Cheers!
rangel ¶
3 years ago
The term "autoload" mentioned here shall not be confused with __autoload function to autoload objects. Regarding the __autoload and namespaces' resolution I'd like to share the following experience:
->Say you have the following directory structure:
- root
| - loader.php
| - ns
| - foo.php
->foo.php
<?php
namespace ns;
class foo
{
public $say;
public function __construct()
{
$this->say = "bar";
}
}
?>
-> loader.php
<?php
//GLOBAL SPACE <--
function __autoload($c)
{
require_once $c . ".php";
}
class foo extends ns\foo // ns\foo is loaded here
{
public function __construct()
{
parent::__construct();
echo "<br />foo" . $this->say;
}
}
$a = new ns\foo(); // ns\foo also loads ns/foo.php just fine here.
echo $a->say; // prints bar as expected.
$b = new foo; // prints foobar just fine.
?>
If you keep your directory/file matching namespace/class consistence the object __autoload works fine.
But... if you try to give loader.php a namespace you'll obviously get fatal errors.
My sample is just 1 level dir, but I've tested with a very complex and deeper structure. Hope anybody finds this useful.
Cheers!
safakozpinar at NOSPAM dot gmail dot com ¶
2 years ago
As working with namespaces and using (custom or basic) autoload structure; magic function __autoload must be defined in global scope, not in a namespace, also not in another function or method.
<?php
namespace Glue {
/**
* Define your custom structure and algorithms
* for autoloading in this class.
*/
class Import
{
public static function load ($classname)
{
echo 'Autoloading class '.$classname."\n";
require_once $classname.'.php';
}
}
}
/**
* Define function __autoload in global namespace.
*/
namespace {
function __autoload ($classname)
{
\Glue\Import::load($classname);
}
}
?>
sammaye ¶
2 years ago
I have noticed one problem with __autoload function. Say you have two namespaces, one is a sub of the other:
\Glue
\Glue\Import
Within that Import namespace you have a function auto() with the magic __autoload inside. No matter what you do that auto() will never traverse it's sub function meaning you will nevber get an __autoload function.
Even if you put the __autoload within a class within the namespace as such:
<?php
namespace Glue\Import;
class import{
private static $_AutoLoad = array();
private static $_Imported = array();
function load($sName){
if(! isset(self::$_AutoLoad[$sName]))
//throw new ImportError("Cannot import module with name '$sName'.");
echo("file with name '$sName' failed to load with path '".self::$_AutoLoad[$sName]."'");
if(! isset(self::$_Imported[$sName])){
self::$_Imported[$sName] = True;
return include_once(self::$_AutoLoad[$sName]);
}
}
function push($sName, $sPath){
self::$_AutoLoad[$sName] = $sPath;
}
function auto(){
function __autoload($sClass){
load($sClass);
}
}
}
?>
It will not work. Just something to keep in mind.