PHP Object-Oriented Programming and reflection API details, object-oriented reflection

PHP Object-Oriented Programming and reflection API details, object-oriented reflection

This article describes PHP Object-Oriented Programming and reflection APIs. We will share this with you for your reference. The details are as follows:

Understanding class

Class_exists

<? Php // TaskRunner. php $ classname = "Task"; $ path = "tasks/{$ classname}. php"; if (! File_exists ($ path) {throw new Exception ("No such file as {$ path}"); // throw an Exception, class file does not exist} require_once ($ path ); $ qclassname = "tasks \ $ classname"; if (! Class_exists ($ qclassname) {throw new Exception ("No such class as $ qclassname"); // throw an Exception. The class does not have a Fatal error: uncaught exception 'exception' with message' No such class as tasks \ task' Stack trace: #0 {main }}$ myObj = new $ qclassname (); $ myObj-> doSpeak ();?>

Get_class check the instanceof class of the object to verify whether the object belongs to a class

<? Phpclass CdProduct {} function getProduct () {return new CdProduct ("Exile on Coldharbour Lane", "The", "Alabama 3", 10.99, 60.33 ); // return a Class Object} $ product = getProduct (); if (get_class ($ product) = 'cdproduct ') {print "\ $ product is a CdProduct object \ n" ;}?> <? Phpclass 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 obtains the list of all methods in the class. Only public methods, protected and private methods are obtained. The default value is public.

<?phpclass 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)

More Verification

<?phpclass 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 nameprint $product->$method(); // invoke the methodif ( 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:

titletitletitletitleArray(  [coverUrl] =>)CdProduct is a subclass of ShopProductCdProduct is a subclass of incidentalCdProduct is an interface of incidental

_ Call Method

<? Phpclass 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) {// execute the call method if (method_exists ($ this-> thirdpartyShop, $ method) when the unnamed method is called )) {return $ this-> thirdpartyShop-> $ method () ;}}$ d = new Deltas Tor (); $ d-> thing ();?>

Output:

Thing

Parameter passing

<?phpclass 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)

Reflection API

Fullshop. php

<?phpclass 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 $product2->getSummaryLine()."\n";*/?><?phprequire_once "fullshop.php";$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  } }}

Comment: The class is better than var_dump. What attributes are inherited and what classes are inherited. The methods in the class are self-defined, overwritten, and inherited.

View class data

<?phprequire_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

View Method Data

<?phprequire_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 definedgetPlayLength is public----getSummaryLine is user definedgetSummaryLine is public----getProducerFirstName is user definedgetProducerFirstName is public----getProducerMainName is user definedgetProducerMainName is public----setDiscount is user definedsetDiscount is public----getDiscount is user definedgetDiscount is public----getTitle is user definedgetTitle is public----getPrice is user definedgetPrice is public----getProducer is user definedgetProducer is public

Obtain the constructor Parameters

<?phprequire_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