PHP面向对象程序设计之类与反射API详解
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2024-04-01 22:02:52
本文实例讲述了php面向对象程序设计之类与反射api。分享给大家供大家参考，具体如下：
了解类
class_exists验证类是否存在
本文实例讲述了php面向对象程序设计之类与反射api。分享给大家供大家参考，具体如下：
了解类
class_exists验证类是否存在
<?php
// taskrunner.php
$classname = "task";
$path = "tasks/{$classname}.php";
if ( ! file_exists( $path ) ) {
throw new exception( "no such file as {$path}" ); //抛出异常,类文件不存在
}
require_once( $path );
$qclassname = "tasks\\$classname";
if ( ! class_exists( $qclassname ) ) {
throw new exception( "no such class as $qclassname" ); //抛出异常,类不存在fatal error: uncaught exception 'exception' with message 'no such class as tasks\task'
stack trace:
#0 {main}
}
$myobj = new $qclassname();
$myobj->dospeak();
?>
get_class 检查对象的类 instanceof 验证对象是否属于某个类
<?php
class cdproduct {}
function getproduct() {
return new cdproduct( "exile on coldharbour lane",
"the", "alabama 3", 10.99, 60.33 ); // 返回一个类对象
}
$product = getproduct();
if ( get_class( $product ) == 'cdproduct' ) {
print "\$product is a cdproduct object\n";
}
?>
<?php
class cdproduct {}
function getproduct() {
return new cdproduct( "exile on coldharbour lane",
"the", "alabama 3", 10.99, 60.33 );
}
$product = getproduct();
if ( $product instanceof cdproduct ) {
print "\$product is a cdproduct object\n";
}
?>
get_class_methods 得到类中所有的方法列表,只获取public的方法，protected，private的方法获取不到。默认的就是public。
<?php
class cdproduct {
function __construct() { }
function getplaylength() { }
function getsummaryline() { }
function getproducerfirstname() { }
function getproducermainname() { }
function setdiscount() { }
function getdiscount() { }
function gettitle() { }
function getprice() { }
function getproducer() { }
}
print_r( get_class_methods( 'cdproduct' ) );
?>
output:
array ( [0] => __construct [1] => getplaylength [2] => getsummaryline [3] => getproducerfirstname [4] => getproducermainname [5] => setdiscount [6] => getdiscount [7] => gettitle [8] => getprice [9] => getproducer )
更多验证
<?php
class shopproduct {}
interface incidental {};
class cdproduct extends shopproduct implements incidental {
public $coverurl;
function __construct() { }
function getplaylength() { }
function getsummaryline() { }
function getproducerfirstname() { }
function getproducermainname() { }
function setdiscount() { }
function getdiscount() { }
function gettitle() { return "title\n"; }
function getprice() { }
function getproducer() { }
}
function getproduct() {
return new cdproduct();
}
$product = getproduct(); // acquire an object
$method = "gettitle"; // define a method name
print $product->$method(); // invoke the method
if ( in_array( $method, get_class_methods( $product ) ) ) {
print $product->$method(); // invoke the method
}
if ( is_callable( array( $product, $method) ) ) {
print $product->$method(); // invoke the method
}
if ( method_exists( $product, $method ) ) {
print $product->$method(); // invoke the method
}
print_r( get_class_vars( 'cdproduct' ) );
if ( is_subclass_of( $product, 'shopproduct' ) ) {
print "cdproduct is a subclass of shopproduct\n";
}
if ( is_subclass_of( $product, 'incidental' ) ) {
print "cdproduct is a subclass of incidental\n";
}
if ( in_array( 'incidental', class_implements( $product )) ) {
print "cdproduct is an interface of incidental\n";
}
?>
output:
title title title title array ( [coverurl] => ) cdproduct is a subclass of shopproduct cdproduct is a subclass of incidental cdproduct is an interface of incidental
__call方法
<?php
class othershop {
function thing() {
print "thing\n";
}
function andanotherthing() {
print "another thing\n";
}
}
class delegator {
private $thirdpartyshop;
function __construct() {
$this->thirdpartyshop = new othershop();
}
function __call( $method, $args ) { // 当调用未命名方法时执行call方法
if ( method_exists( $this->thirdpartyshop, $method ) ) {
return $this->thirdpartyshop->$method( );
}
}
}
$d = new delegator();
$d->thing();
?>
output:
thing
传参使用
<?php
class othershop {
function thing() {
print "thing\n";
}
function andanotherthing( $a, $b ) {
print "another thing ($a, $b)\n";
}
}
class delegator {
private $thirdpartyshop;
function __construct() {
$this->thirdpartyshop = new othershop();
}
function __call( $method, $args ) {
if ( method_exists( $this->thirdpartyshop, $method ) ) {
return call_user_func_array(
array( $this->thirdpartyshop,
$method ), $args );
}
}
}
$d = new delegator();
$d->andanotherthing( "hi", "hello" );
?>
output:
another thing (hi, hello)
反射api
fullshop.php
<?php
class shopproduct {
private $title;
private $producermainname;
private $producerfirstname;
protected $price;
private $discount = 0;
public function __construct( $title, $firstname,
$mainname, $price ) {
$this->title = $title;
$this->producerfirstname = $firstname;
$this->producermainname = $mainname;
$this->price = $price;
}
public function getproducerfirstname() {
return $this->producerfirstname;
}
public function getproducermainname() {
return $this->producermainname;
}
public function setdiscount( $num ) {
$this->discount=$num;
}
public function getdiscount() {
return $this->discount;
}
public function gettitle() {
return $this->title;
}
public function getprice() {
return ($this->price - $this->discount);
}
public function getproducer() {
return "{$this->producerfirstname}".
" {$this->producermainname}";
}
public function getsummaryline() {
$base = "{$this->title} ( {$this->producermainname}, ";
$base .= "{$this->producerfirstname} )";
return $base;
}
}
class cdproduct extends shopproduct {
private $playlength = 0;
public function __construct( $title, $firstname,
$mainname, $price, $playlength=78 ) {
parent::__construct( $title, $firstname,
$mainname, $price );
$this->playlength = $playlength;
}
public function getplaylength() {
return $this->playlength;
}
public function getsummaryline() {
$base = parent::getsummaryline();
$base .= ": playing time - {$this->playlength}";
return $base;
}
}
class bookproduct extends shopproduct {
private $numpages = 0;
public function __construct( $title, $firstname,
$mainname, $price, $numpages ) {
parent::__construct( $title, $firstname,
$mainname, $price );
$this->numpages = $numpages;
}
public function getnumberofpages() {
return $this->numpages;
}
public function getsummaryline() {
$base = parent::getsummaryline();
$base .= ": page count - {$this->numpages}";
return $base;
}
public function getprice() {
return $this->price;
}
}
/*
$product1 = new cdproduct("cd1", "bob", "bobbleson", 4, 50 );
print $product1->getsummaryline()."\n";
$product2 = new bookproduct("book1", "harry", "harrelson", 4, 30 );
print $product2->getsummaryline()."\n";
*/
?>
<?php
require_once "fullshop.php";
$prod_class = new reflectionclass( 'cdproduct' );
reflection::export( $prod_class );
?>
output:
class [ <user> class cdproduct extends shopproduct ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 53-73
- constants [0] {
}
- static properties [0] {
}
- static methods [0] {
}
- properties [2] {
property [ <default> private $playlength ]
property [ <default> protected $price ]
}
- methods [10] {
method [ <user, overwrites shopproduct, ctor> public method __construct ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 56 - 61
- parameters [5] {
parameter #0 [ <required> $title ]
parameter #1 [ <required> $firstname ]
parameter #2 [ <required> $mainname ]
parameter #3 [ <required> $price ]
parameter #4 [ <optional> $playlength = 78 ]
}
}
method [ <user> public method getplaylength ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 63 - 65
}
method [ <user, overwrites shopproduct, prototype shopproduct> public method getsummaryline ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 67 - 71
}
method [ <user, inherits shopproduct> public method getproducerfirstname ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 17 - 19
}
method [ <user, inherits shopproduct> public method getproducermainname ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 21 - 23
}
method [ <user, inherits shopproduct> public method setdiscount ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 25 - 27
- parameters [1] {
parameter #0 [ <required> $num ]
}
}
method [ <user, inherits shopproduct> public method getdiscount ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 29 - 31
}
method [ <user, inherits shopproduct> public method gettitle ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 33 - 35
}
method [ <user, inherits shopproduct> public method getprice ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 37 - 39
}
method [ <user, inherits shopproduct> public method getproducer ] {
@@ d:\xampp\htdocs\popp-code\5\fullshop.php 41 - 44
}
}
}
点评：把类看的透彻的一塌糊涂，比var_dump强多了。哪些属性，继承了什么类。类中的方法哪些是自己的，哪些是重写的，哪些是继承的，一目了然。
查看类数据
<?php
require_once("fullshop.php");
function classdata( reflectionclass $class ) {
$details = "";
$name = $class->getname();
if ( $class->isuserdefined() ) {
$details .= "$name is user defined\n";
}
if ( $class->isinternal() ) {
$details .= "$name is built-in\n";
}
if ( $class->isinterface() ) {
$details .= "$name is interface\n";
}
if ( $class->isabstract() ) {
$details .= "$name is an abstract class\n";
}
if ( $class->isfinal() ) {
$details .= "$name is a final class\n";
}
if ( $class->isinstantiable() ) {
$details .= "$name can be instantiated\n";
} else {
$details .= "$name can not be instantiated\n";
}
return $details;
}
$prod_class = new reflectionclass( 'cdproduct' );
print classdata( $prod_class );
?>
output:
cdproduct is user defined
cdproduct can be instantiated
查看方法数据
<?php
require_once "fullshop.php";
$prod_class = new reflectionclass( 'cdproduct' );
$methods = $prod_class->getmethods();
foreach ( $methods as $method ) {
print methoddata( $method );
print "\n----\n";
}
function methoddata( reflectionmethod $method ) {
$details = "";
$name = $method->getname();
if ( $method->isuserdefined() ) {
$details .= "$name is user defined\n";
}
if ( $method->isinternal() ) {
$details .= "$name is built-in\n";
}
if ( $method->isabstract() ) {
$details .= "$name is abstract\n";
}
if ( $method->ispublic() ) {
$details .= "$name is public\n";
}
if ( $method->isprotected() ) {
$details .= "$name is protected\n";
}
if ( $method->isprivate() ) {
$details .= "$name is private\n";
}
if ( $method->isstatic() ) {
$details .= "$name is static\n";
}
if ( $method->isfinal() ) {
$details .= "$name is final\n";
}
if ( $method->isconstructor() ) {
$details .= "$name is the constructor\n";
}
if ( $method->returnsreference() ) {
$details .= "$name returns a reference (as opposed to a value)\n";
}
return $details;
}
?>
output:
__construct is user defined __construct is public __construct is the constructor ---- getplaylength is user defined getplaylength is public ---- getsummaryline is user defined getsummaryline is public ---- getproducerfirstname is user defined getproducerfirstname is public ---- getproducermainname is user defined getproducermainname is public ---- setdiscount is user defined setdiscount is public ---- getdiscount is user defined getdiscount is public ---- gettitle is user defined gettitle is public ---- getprice is user defined getprice is public ---- getproducer is user defined getproducer is public
获取构造函数参数情况
<?php
require_once "fullshop.php";
$prod_class = new reflectionclass( 'cdproduct' );
$method = $prod_class->getmethod( "__construct" );
$params = $method->getparameters();
foreach ( $params as $param ) {
print argdata( $param )."\n";
}
function argdata( reflectionparameter $arg ) {
$details = "";
$declaringclass = $arg->getdeclaringclass();
$name = $arg->getname();
$class = $arg->getclass();
$position = $arg->getposition();
$details .= "\$$name has position $position\n";
if ( ! empty( $class ) ) {
$classname = $class->getname();
$details .= "\$$name must be a $classname object\n";
}
if ( $arg->ispassedbyreference() ) {
$details .= "\$$name is passed by reference\n";
}
if ( $arg->isdefaultvalueavailable() ) {
$def = $arg->getdefaultvalue();
$details .= "\$$name has default: $def\n";
}
if ( $arg->allowsnull() ) {
$details .= "\$$name can be null\n";
}
return $details;
}
?>
output:
$title has position 0 $title can be null $firstname has position 1 $firstname can be null $mainname has position 2 $mainname can be null $price has position 3 $price can be null $playlength has position 4 $playlength has default: 78 $playlength can be null
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