Objects and references
In response to Amir Abiri's comment:
In this example:
<?php
//---
// global.php
class A {
public static function foo() {
echo "static function";
}
}
//----
// namespace.php
namespace A;
function foo() {
echo "namespace function";
}
?>
The way to call each of these functions is like so:
<?php
A::foo(); // "namespace function"
::A::foo(); // "static function"
?>
This could get pretty confusing, but at least now you know. :)
Namespaces
Spis treści
Namespaces overview
Namespaces in PHP are designed to solve scoping problem in large PHP libraries. In PHP, all class definitions are global. Thus, when a library author creates various utility or public API classes for the library, he must be aware of the possibility that other libraries with similar functionality would exist and thus choose unique names so that these libraries could be used together. Usually it is solved by prefixing the class names with an unique string - e.g., database classes would have prefix My_Library_DB, etc. As the library grows, prefixes add up, leading to the very long names.
The namespaces allow the developer to manage naming scopes without using the long names each time the class is referred to, and solve the problem of shared globals space without making code unreadable.
Namespaces are available in PHP as of PHP 5.3.0. This section is experimental and subject to changes.
add a note
User Contributed NotesNamespaces
nickf
31-Aug-2008 06:01
31-Aug-2008 06:01
j dot s dot lubbers at gmail dot com
01-Aug-2008 03:02
01-Aug-2008 03:02
This is my 'ultimate' autoload functie:
<?php
function __autoload($class) {
require('../includes/classes/' . str_replace('::', '/', strtolower($class)) . '.php');
}
//When you do:
$object = new PDF::Document();
?>
it will include the file:
../includes/classes/pdf/document.php
as you will notice I like to keep my includes outside the webroot.
document.php
<?php
namespace PDF;
class Document {
//etc...
}
?>
Tito
16-Jul-2008 09:31
16-Jul-2008 09:31
you can use __autoload to automaticly include Classes with a "use" / "new" statement.
yarco dot w at gmail dot com
01-Jul-2008 01:19
01-Jul-2008 01:19
So do you mean if i want to use a class, i need to do extra two steps?
1) require/include that file
2) use the namespace
What about to add a trigger something like:
function __auto_namespace($names, $class)
{
if ($class === null)
{
set_include_dir(implode('/', $names));
}
else
{
require_once implode('/', $names).'/'.$class.'.php';
}
}
Then when we:
use NAMESPACE1::NAMESPACE2;
or
use NAMESPACE1::NAMESPACE2::CLASS1;
php could auto include the file we needed.
Amir Abiri
25-Dec-2007 05:31
25-Dec-2007 05:31
So, if I understand correctly there is a possible ambiguity that can cause a function or method to become "masked".
If I have:
global.php:
<?php
class A
{
static public function foo()
{
}
}
A::foo(); // Will statically call method foo() of class ::A.
?>
If I now added the following to my project:
A.php:
<?php
namespace A;
function foo()
{
}
?>
The function call above would instead call this new function.
It shouldn't be a problem most of the time and specially if certain basic practices are followed (For example, don't name classes and namespaces the same name, and always keep different packages in their own separate namespaces), but it's something to keep in mind.