PHP Namespaces (Namespace) Concise tutorial _php Tutorial

This feature was raised at the time of Php5.0x and was later canceled and implemented in PHP6. And this time again "advance" to the PHP5.3 release, it can be seen that the developer of its attention and cautious attitude.

The description of the document may be out of date (documentation maybe out dated), so here's a simple description of the namespace usage: first declaring a namespace, adding a new keyword namespace, which should be at the beginning of the class file

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namespace Project::module;
Class User {
Const STATUS_OK = true;
function Register ($data) {
...
}
...
}?>

It can then be called in the controller (possibly other files)

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$user = new Project::module::user ();
$user->register ($register _info);
It's certainly not the same as usual, but we can relate two separate classes. Like what

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Project::module::user;
Project::module::blog;
This makes it easier to describe and understand the relationships between variables and classes from the language itself, thus avoiding the lengthy naming of the "traditional" project_module_blog.

The above instructions may be difficult to explain what benefits are being used with namespaces, and the newly added use and as keywords may better illustrate the problem. Use and as statements can refer to and declare "aliases" of namespaces. For example, the code for instantiating classes in the above controller can be written like this

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Use Project::module;
$user = new Module::user ();
$user->register ($register _info);
Even

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Use Project::module::user as Moduleuser;
$user = new Moduleuser;
$user->register ($register _info);
A constant in a class can also be accessed through a namespace, such as STATUS_OK in the above class, through a namespace

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Project::module::user::status_ok
Access. Further, you can also use aliases to simplify so long "variable names"

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Use PROJECT::MODULE::USER::STATUS_OK as STATUS_OK;
Echo STATUS_OK;
By the way, the concept of "hyperspace (the Global Namespace)" is mentioned. The so-called "hyperspace" is a variable, class, and function that does not specify a namespace. Like what

Copy the Code code as follows:
function foo () {
...
}
This function can be performed using Foo () and can also be used:: foo (); This executes.

Finally, you can load a class of the specified namespace with the AutoLoad function. The simple functions are as follows

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function __autoload ($classname) {
$classname = Strtolower ($classname);
$classname = Str_replace (':: ', Directory_separator, $classname);
Require_once (DirName (__file__). '/' . $classname. '. class.php ');
}
This, for example, calls

Copy the Code code as follows:
__autoload (' Project::module::user ');
You can automatically load the Project_Module_User.class.php file (although this may not seem convenient).

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