本文的示例代碼參考namespace
目錄
開始
mkdir -p vendor/lib1 && vim vendor/lib1/Person.php
<?php
class Person
{
var $name, $age;
function __construct($name, $age)
{
echo "__construct of lib1/Person.php" . "\n";
$this->name = $name;
$this->age = $age;
}
}
PHP語法參考 X分鐘速成Y - 其中 Y=PHP
vim startup.php
<?php
require_once "vendor/lib1/Person.php";
$person = new Person("David", 6);
var_dump($person);
php startup.php
__construct of lib1/Person.php
object(Person)#1 (2) {
["name"]=>
string(5) "David"
["age"]=>
int(6)
}
PHP環(huán)境搭建參考 PHP學習 之 autoload
命名沖突
mkdir -p vendor/lib2 && vim vendor/lib2/Person.php
<?php
class Person
{
var $name, $age;
function __construct($name, $age)
{
echo "__construct of lib2/Person.php" . "\n";
$this->name = $name;
$this->age = $age;
}
}
vim conflict.php
<?php
require_once "vendor/lib1/Person.php";
require_once "vendor/lib2/Person.php";
$person = new Person("David", 6);
var_dump($person);
php conflict.php
PHP Fatal error: Cannot declare class Person, because the name is already in use in /Users/yuanlin/Workspace/php-tutorial/namespace/vendor/lib2/Person.php on line 2
命名空間
- vendor/lib1/Person.php
vim vendor/lib1/Person.php
<?php
namespace lib1;
class Person
{
var $name, $age;
function __construct($name, $age)
{
echo "__construct of lib1/Person.php" . "\n";
$this->name = $name;
$this->age = $age;
}
}
echo "namespace: ". __NAMESPACE__ . "\n";
php vendor/lib1/Person.php
namespace: lib1
常量
__NAMESPACE__的值是包含當前命名空間名稱的字符串
- vendor/lib2/Person.php
vim vendor/lib2/Person.php
<?php
namespace lib2;
class Person
{
var $name, $age;
function __construct($name, $age)
{
echo "__construct of lib2/Person.php" . "\n";
$this->name = $name;
$this->age = $age;
}
}
echo "namespace: ". __NAMESPACE__ . "\n";
php vendor/lib2/Person.php
namespace: lib2
- namespace.php
vim namespace.php
<?php
require_once "vendor/lib1/Person.php";
require_once "vendor/lib2/Person.php";
$person = new lib1\Person("David", 6);
var_dump($person);
$person = new lib2\Person("David", 6);
var_dump($person);
echo "namespace: ". __NAMESPACE__ . "\n";
php namespace.php
namespace: lib1
namespace: lib2
__construct of lib1/Person.php
object(lib1\Person)#1 (2) {
["name"]=>
string(5) "David"
["age"]=>
int(6)
}
__construct of lib2/Person.php
object(lib2\Person)#2 (2) {
["name"]=>
string(5) "David"
["age"]=>
int(6)
}
namespace:
在全局的即不包括在任何命名空間中的代碼 常量
__NAMESPACE__的值是包含一個空的字符串
全局空間
在名稱前加上前綴\表示該名稱是全局空間中的名稱
vim global.php
<?php
echo strlen('123') . "\n";
echo \strlen('123') . "\n";
php global.php
3
3
引用規(guī)則
非限定名稱
vim regular_1.php
<?php
namespace app;
require_once "vendor/lib1/Person.php";
require_once "vendor/lib2/Person.php";
$person = new Person("David", 6);
var_dump($person);
php regular_1.php
PHP Fatal error: Uncaught Error: Class 'app\Person' not found in /Users/yuanlin/Workspace/php-tutorial/namespace/regular_1.php:8
非限定名稱引用: current namespace + 非限定名稱
PS: 非限定名稱的詳細定義參考 使用命名空間：基礎(chǔ)
限定名稱
vim regular_2.php
<?php
namespace app;
require_once "vendor/lib1/Person.php";
require_once "vendor/lib2/Person.php";
$person = new lib1\Person("David", 6);
var_dump($person);
php regular_2.php
PHP Fatal error: Uncaught Error: Class 'app\lib1\Person' not found in /Users/yuanlin/Workspace/php-tutorial/namespace/regular_2.php:8
限定名稱引用: current namespace + 限定名稱
完全限定名稱
vim regular_3.php
<?php
namespace app;
require_once "vendor/lib1/Person.php";
require_once "vendor/lib2/Person.php";
$person = new \lib1\Person("David", 6);
var_dump($person);
php regular_3.php
__construct of lib1/Person.php
object(lib1\Person)#1 (2) {
["name"]=>
string(5) "David"
["age"]=>
int(6)
}
完全限定名稱引用: 完全限定名稱
引用別名
vim alias.php
<?php
require_once "vendor/lib1/Person.php";
use lib1\Person as User;
$user = new User("David", 6);
var_dump($user);
php alias.php
__construct of lib1/Person.php
自動加載
PSR-0
PSR (PHP Standards Recommendations)
FIG (PHP Framework Interop Group) - Moving PHP forward through collaboration and standards
Deprecated - As of 2014-10-21 PSR-0 has been marked as deprecated. PSR-4 is now recommended
as an alternative
PSR-4
mkdir -p autoload/psr4 && cd autoload/psr4
vim composer.json
{
"autoload": {
"psr-4": {
"App\\": "app/"
}
}
}
mkdir -p app/Core && vim app/Core/Request.php
<?php
namespace App\Core;
class Request {
function __construct()
{
echo "__construct of App\Core\Request.php" . "\n";
}
}
echo "namespace: ". __NAMESPACE__ . "\n";
composer update
vim psr4.php
<?php
require __DIR__.'/vendor/autoload.php';
use App\Core\Request;
$request = new Request();
php psr4.php
namespace: App\Core
__construct of App\Core\Request.php
classmap
cd ../..
mkdir -p autoload/classmap && cd autoload/classmap
vim composer.json
{
"autoload": {
"classmap": [
"app"
]
}
}
mkdir -p app/Core && vim app/Core/Request.php
<?php
namespace App\Core;
class Request {
function __construct()
{
echo "__construct of App\Core\Request.php" . "\n";
}
}
echo "namespace: ". __NAMESPACE__ . "\n";
composer update
vim classmap.php
<?php
require __DIR__.'/vendor/autoload.php';
use App\Core\Request;
$request = new Request();
php psr4.php
namespace: App\Core
__construct of App\Core\Request.php
classmap與PSR-4這兩種autoload方式有何區(qū)別?
files
cd ../..
mkdir -p autoload/files && cd autoload/files
vim composer.json
{
"autoload": {
"files": [
"app/Core/Request.php"
]
}
}
mkdir -p app/Core && vim app/Core/Request.php
<?php
namespace App\Core;
class Request {
function __construct()
{
echo "__construct of App\Core\Request.php" . "\n";
}
}
echo "namespace: ". __NAMESPACE__ . "\n";
composer update
vim files.php
<?php
require __DIR__.'/vendor/autoload.php';
use App\Core\Request;
$request = new Request();
php files.php
namespace: App\Core
__construct of App\Core\Request.php
files這種autoload方式的應(yīng)用場景?
