Objects and references
the previously submitted note is incorrect.
A::foo();
is identical to
::A::foo();
in the global namespace.
The only way to successfully call the static method is to instantiate A and call it like:
<?php
$a = new A;
$a->foo();
?>
or to use reflection. This limitation is addressed in patches I have proposed, so the implementation may yet be usable in this regard.
Namespaces
Índice
Namespaces - Visão geral
Namespaces no PHP são projetados para resolver problema de escopo em bibliotecas PHP extensas. No PHP, todas as definições de classes são globais. Assim, quando uma autor de uma biblioteca cria vários utilitários ou públicas classes para uma biblioteca, ele precisa ter cuidado com a possibilidade de outra biblioteca com mesma funcionalidade exista e assim escolher nomes únicos para que estas bibliotecas possam ser usadas juntas. Normalmente isto é resolvido prefixando o nome da classe com uma string única - e.g., classes de banco de dados tem prefixo My_Library_DB, etc. Com o crescimento da biblioteca, mais prefixos são adicionados, criando então nomes grandes.
Os namespaces permitem o desenvolvedor manusear nomes num escopo sem usar nomes grandes cada vez que a classe for referenciada, e resolver o problema de espaço global compartilhado sem fazer um código ilegível.
Namespaces está disponível a partir do PHP 5.3.0. Esta seção é experimental e sujeita a mudanças.
User Contributed Notes
Namespaces
Namespaces
greg at chiaraquartet dot net
22-Sep-2008 12:32
22-Sep-2008 12:32
nickf
31-Aug-2008 10:01
31-Aug-2008 10:01
In response to Amir Abiri's comment:
In this example:
<?php
//---
// global.php
class A {
public static function foo() {
echo "static function";
}
}
//----
// namespace.php
namespace A;
function foo() {
echo "namespace function";
}
?>
The way to call each of these functions is like so:
<?php
A::foo(); // "namespace function"
::A::foo(); // "static function"
?>
This could get pretty confusing, but at least now you know. :)
j dot s dot lubbers at gmail dot com
01-Aug-2008 07:02
01-Aug-2008 07:02
This is my 'ultimate' autoload functie:
<?php
function __autoload($class) {
require('../includes/classes/' . str_replace('::', '/', strtolower($class)) . '.php');
}
//When you do:
$object = new PDF::Document();
?>
it will include the file:
../includes/classes/pdf/document.php
as you will notice I like to keep my includes outside the webroot.
document.php
<?php
namespace PDF;
class Document {
//etc...
}
?>
Tito
16-Jul-2008 01:31
16-Jul-2008 01:31
you can use __autoload to automaticly include Classes with a "use" / "new" statement.
yarco dot w at gmail dot com
01-Jul-2008 05:19
01-Jul-2008 05:19
So do you mean if i want to use a class, i need to do extra two steps?
1) require/include that file
2) use the namespace
What about to add a trigger something like:
function __auto_namespace($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 11:31
25-Dec-2007 11:31
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.