Cast derived class to base class in php - php

I'm probably missing something obvious here as this is basic functionality in other OOP languages, but I'm struggling with PHP way of doing this. I understand that PHP is not "true" OOP language, but still...
What I'm after is casting an object instantiated as derived class to base class. Something along the lines of:
class Some{}
class SomeMock extends Some {}
function GetSomeMock(){
$mock = new SomeMock();
return (Some)$mock; //Syntax error here
}
I've found some questions with strange request of downcasting objects of base class to derived which is possible with some nasty tweaks, but this basic functionality does not have to be that difficult. What am I missing here?
Edit: It seems that it's always matter what I'm trying to achieve. No problem. GetSomeMock() is a factory method that would return a mock object stub (derived from base class, all properties prepopulated in constructor) with expected properties' values. I would then compare it to another object of base type that is restored from database:
$this->assertEquals($mockObject, $realObject);
This fails instantly as $mockObject and $realObject are of different types. I can imagine there are many workarounds I can implement to achieve the same, but I'd like to keep things as simple as possible.

Ok, the short answer seems to be: This is not possible. PHP knows better than me what type I need.

In PHP you cannot cast to a specific class, I cannot even see any need for that.
You may cast to some native type - string, int, array, object. But not a specific class.
If you need to use some functionality of a base class, you can do it via parent keyword.
class Some {
public function execute(){
echo "I am some" ;
}
}
class SomeMock extends Some {
public function execute(){ //Override the function
parent::execute() ; //Here you can execute parent's functionality and add some more
}
}
Edit:
instanceof operator may come handy. When comparing objects.
For instance:
$object = new SomeMock() ;
$status = ($object instanceof Some && $object instanceof SomeMock); //will return true here ;
Child classes inherit non-private properties and methods.
Let's say, you have your function:
function assertEquals($mockObject, $realObject){
if ($mockObject instanceof Some && $realObject instanceof Some){
//Both objects have the same base class - Some
//That means they must have inherited the functionality and properties of Some class.
}
}

You can do it with an custom function:
private function castParameter(BaseClass $parameters) : DerivedClass {
return $parameters;
}

I did come across use cases when I needed to cast a derived class to its base class. I did the following.
function castToParentClass($derivedClassInstance) {
$parentClassName = get_parent_class($derivedClassInstance);
$parentClassInstance = new $parentClassName();
foreach ($parentClassInstance as $key => $value) {
$parentClassInstance->{$key} = $derivedClassInstance->{$key};
}
return $parentClassInstance;
}

Related

PHP - override function with different number of parameters

I'm extending a class, but in some scenarios I'm overriding a method. Sometimes in 2 parameters, sometimes in 3, sometimes without parameters.
Unfortunately I'm getting a PHP warning.
My minimum verifiable example:
http://pastebin.com/6MqUX9Ui
<?php
class first {
public function something($param1) {
return 'first-'.$param1;
}
}
class second extends first {
public function something($param1, $param2) {
return 'second params=('.$param1.','.$param2.')';
}
}
// Strict standards: Declaration of second::something() should be compatible with that of first::something() in /home/szymon/webs/wildcard/www/source/public/override.php on line 13
$myClass = new Second();
var_dump( $myClass->something(123,456) );
I'm getting PHP error/warning/info:
How can I prevent errors like this?
you can redefine methods easily adding new arguments, it's only needs that the new arguments are optional (have a default value in your signature). See below:
class Parent
{
protected function test($var1) {
echo($var1);
}
}
class Child extends Parent
{
protected function test($var1, $var2 = null) {
echo($var1);
echo($var1);
}
}
For more detail, check out the link: http://php.net/manual/en/language.oop5.abstract.php
Another solution (a bit "dirtier") is to declare your methods with no argument at all, and in your methods to use the func_get_args() function to retrieve your arguments...
http://www.php.net/manual/en/function.func-get-args.php
As of PHP 8.1, there's a cool hack to override a class's method with extra number of required arguments. You should use the new new in initializers feature. But how?
We define a class having a constructor always throwing a ArgumentCountError, and make it the default value of every extra required parameter (an improved version of #jose.serapicos's answer). Simple and cool!
Now let's see it in action. First, we define RequiredParam:
final class RequiredParameter extends \ArgumentCountError
{
public function __construct()
{
// Nested hack
throw $this;
}
}
And then:
class Base
{
public function something(string $baseParam): string
{
return $baseParam;
}
}
class Derived extends Base
{
public function something(
string $baseParam,
string|RequiredParameter $extraParam = new RequiredParameter(),
): string {
return "$baseParam + $extraParam";
}
}
This way, no one can bypass the extra parameters, because RequiredParameter is declared as final. It works for interfaces as well.
How Good or Bad is This?
One advantage is that it's a little more flexible than setting default parameters as null, as you can pass the constructor of RequiredParameter an arbitrary list of parameters and probably build a custom error message.
Another advantage is that it's handled less manually, and thus being more safe. You may forget about handling a null value, but RequiredParameter class handles things for you.
One major disadvantage of this method is that it breaks the rules. First and foremost, you must ask yourself why you would need this, because it breaks polymorphism in most cases. Use it with caution.
However, there are valid use cases for this, like extending parent class's method with the same name (if you cannot modify the parent, otherwise I recommend you to use traits instead), and using the child class as standalone (i.e. without the help of parent class's type).
Another disadvantage is that it requires you to use union types for each parameter. While the following workaround is possible, but it requires you to create more classes, which may hurt understandability of your code, as well as having little impact on maintainability and performance (based on your conditions). BTW, no hack comes for free.
Eliminating the use of Union Type
You could extend from or implement RequiredParameter the compatible type of the actual parameter to be able to remove the need for union type:
class BaseRequiredParameter extends Base
{
public function __construct()
{
throw new \ArgumentCountError();
}
}
class Derived extends Base
{
public function something(
string $baseParam,
Base $extraParam = new BaseRequiredParameter()
): string {
return "$baseParam + {$extraParam->something()}";
}
}
It's also possible for strings, if you implement the Stringable interface (e.g. Throwable implements it by default). It doesn't work for some primitive types including bool, int, float, callable, array, etc., however, if you're interested, you're still able to use some alternatives like Closure or Traversable.
For making your life easier, you may want to define the constructor as a trait and use it (I'm aware of this answer, but in fact, this is a valid useful case for a constructor in a trait, at least IMO).
Your interface/abstract class or the most parent class, should cotantin the maximum number of params a method could recieve, you can declare them explicitely to NULL, so if they are not given, no error will occur i.e.
Class A{
public function smth($param1, $param2='', $param3='')
Class B extends A {
public function smth($param1, $param2, $param3='')
Class C extends B {
public function smth($param1, $param2, $param3);
In this case, using the method smth() as an object of 'A' you will be obligated to use only one param ($param1), but using the same method as object 'B' you will be oblgiated to use 2 params ($param1, $param2) and instanciating it from C you have to give all the params

Dependency injection and/or factory pattern

Not sure if my title is correct cause I am not even sure I am using the correct terms.
I have a class that has a property that is an object. When setting this property the object has to be created. My question is how do I do this without tight coupling?
Example:
class A
{
protected $_depending;
protected $_somePropertyObject;
public function __construct(\Lib\Dependency $depending)
{
$this->_setDepending($depending);
}
protected function _setDepending(\Lib\Dependency $depending)
{
$this->_depending = $depending;
}
public function setSomeProperty($someProperty)
{
// I want to prevent this
$this->_somePropertyObject = new \Lib\some\Object($someProperty);
}
}
I could just pass the required object through the construct but what happens more are needed?
When if I understand correctly the factory pattern, what would this change? I would still need to create the object somewhere? Not the object itself but the factory. Again tight coupling? Seems endless to me. When re factoring class(es) it however is isolated where and how the class(es) are made.
If I set the setSomeProperty function to only accept \Lib\some\Object then is still needs to be created by the parent object that is passing it to begin with. Seems only to shift the placement of where it is created?
Hopefully I am clear enough in what I am trying to ask.
Thanks in advance!
EDIT What I am asking is the sequence of what is created when,where,why.
The purpose of a factory in dependency injection patterns is to produce instances for another instance, without that other instance needing to know how to produce it.
At its core, a "factory" is just an object-returner: something that returns an instance when invoked.
This is easier to see in more capable languages. For example in Python classes are callable (there is no new operator), and invoking a class produces an instance of the class. So classes can be their own factories if the class requires no arguments. Likewise any zero-argument function that returns an instance can be considered a factory. This makes dependency injection very clear and free-of-boilerplate.
In more rigid languages (Java/C++/C# static-typed tradition, or where classes or functions are not completely first-class like in PHP), you need to obscure dependency injection behind a "pattern", because "design patterns" are missing language features. In PHP 5.3+ you can use a closure as a factory, or you can go the Java/C# way and define a FactoryInterface and a new class per factory.
For example, with your class, you could do this:
class Aprime extends A
{
public function setSomeProperty($somePropertyFactory)
{
$this->_somePropertyObject = $somePropertyFactory();
}
}
In this class, setSomeProperty requires a zero-argument callable "factory", which you could produce like this:
$other_dep_factory = function(){ return new SomeOtherClass(); };
Or like this:
class ClassFactory {
function __construct($classname, $args=array()) {
$this->class = new ReflectionClass($classname);
$this->args = $args;
}
function __invoke() {
return $this->class->newInstanceArgs($this->args);
}
}
$other_dep_factory = new ClassFactory('SomeOtherClass');
Prior to PHP 5.3, you need to do it like Java would:
interface IObjectFactory {
function getObject();
}
// this B-and-D interface is optional
// it has no body because PHP doesn't support
// type-hinting return values
interface ISomeOtherClassFactory {}
class SomeOtherClassFactory implements ISomeOtherClassFactory {
function getObject() {
return new SomeOtherClass();
}
}
class Aprime extends A
{
public function setSomeProperty(ISomeOtherClassFactory $somePropertyFactory)
{
$this->_somePropertyObject = $somePropertyFactory->getObject();
}
}
$other_dep_factory = new SomeOtherClassFactory();
$myAprimeObject->setSomeProperty($other_dep_factory);
So when do you use a factory? Whenever an object needs to create another object. If the object just needs to use another object, just pass in an instance.
I like to use the Factory Pattern when you need to collect "information" to create the object that's stored in $_somePropertyObject. For instance let's say you have to assign values to some properties to instantiate it or run a couple of methods right after you instantiate it.
Also, you'll want to consider whether you might need to later change the inheritance tree. If you might be assigning $_somePropertyObject a \Lib\some\Object now, you might find yourself wishing you could easily swap it out for a \Lib\some\FancyObject later. If you use Dependency Injection, you can easily swap subtypes.
Here's a primer: http://net.tutsplus.com/tutorials/php/the-whens-and-whys-for-php-design-patterns/
Also, too: https://stackoverflow.com/a/2083455/1121827

PHP - Can I pass a function name as a function argument?

I have two classes that I use to access two different tables in my db. They both have a similar constructor that looks like that:
function __construct($db) {
$this->db = $db;
$userDAO = DAO_DBrecord::createUserDAO($this->db);
$this->userDAO = $userDAO;
}
The other class has the same constructor except that it uses createOtherTableDAO($this->db).
I am planning on having a couple other such classes, and it would be convenient if I could have them all inherit the same constructor, and pass createAppropriateTableDAO as an argument.
To clarify, in the first case above, createUserDAO($this->db) is a static function that calls a constructor in my DAO class. The function in the DAO looks as follows:
public static function createUserDAO($db) {
return new DAO_DBrecord($db, 'users');
}
I use this method to make sure the user model can only call a DAO on the users table.
I'm somewhat of a beginner, and I don't think I have ever seen anything like what I want.
Move the code to create the DAOs into a Factory and then inject the DAOs instead of hard coupling them into whatever these classes are supposed to represent. Or rather create the various Table Data Gateways ("classes that I use to access two different tables") as a whole in the Factory, e.g.
class TableDataGatewayFactory
…
public function create($gatewayName)
{
switch ($gatewayName) {
case 'user':
return new TableDataGateway(new UserDao($this->db)));
break;
default:
throw new Exception('No Gateway for $gatewayName');
}
}
}
As for $this->db, either pass that into the Factory via the ctor or move the creation into the Factory as well. It's somewhat doubled responsibility, but tolerable given that this Factory revolved around creating Database related collaborator graphs.
Apart from that: yes, call_user_func(array('ClassName', 'methodName')) would work. See the manual for
http://php.net/call_user_func and
http://php.net/manual/en/language.pseudo-types.php#language.types.callback
To answer your question first: No, you can't (without resorting to evilCode) pass a function name as a parameter.
But: What you want to archive is a poster-child-issue for an object oriented approach using inheritance.
You'd need a base-class:
class BaseClass
{
function __construct($db) {
$this->db = db;
}
}
and your implementations :
class MyClass extends BaseClass
{
function __construct($db) {
parent::__contruct($db);
$this->userDAO = DAO_DBrecord::createUserDAO($this->db);
}
}
Just for the record: the evilCode would have been
a) you could encapsulate your function in a create_function that can be used as an argument.
b) you could pass the function name as a string to your function and then pass it to eval in the receiving function.
But remember: When eval or create_function looks like the answer you're probably asking the wrong questions!
See: related question
There are several methods which you can use if you feel it necessary to pass the function name or indeed the function itself as a parameter of a function.
call_user_func($function,$args);
call_user_func is one of Php's native functions for invoking methods or functions which takes a function name and optional arguments parameter.
The functionality of call_user_func (when not pertaining to object methods) can be replicated without the using call_user_func using a variable with the string literal of the function name. For example:
function some_func()
{
echo "I'm a function!";
}
$function = "some_func";
$function(); /*Output: I'm a function!*/
And if you're feeling adventurous you can go a bit further and pass a closure / anonymous function as instead of the function name. For example:
$function = function()
{
echo "I'm another function!";
}
$function(); /*Output: I'm another function*/
You can achieve such behavior by using:
call_user_func
eval any literal

What advantage is provided by object overloading in PHP?

PHP object overloading is explained here.
Basically it allows you to define some custom actions when an inaccessible object property or method is accessed.
What are some practical uses for this feature?
Usually, those methods are useful when you are communicating with a 3rd party API or when the method/members structure is unclear.
Let's say you are writing a generic XML-RPC wrapper. Since you don't know the methods available to you before you download the WDL file, it makes sense to use Overloading.
Then, instead of writing the following:
$xmlrpc->call_method('DoSomething', array($arg1, $arg2));
You can use:
$xmlrpc->DoSomething($arg1, $arg2);
which is a more natural syntax.
You can also use member overloading in the same way as method overloading for variable objects.
Just one thing you want to watch for: limit its use only to variable-structure objects or use it only for syntactical shortcuts to getters and setters. It makes sense to keep getters and setters in your class to seperate business logic in multiple methods, but there is nothing wrong in using it as a shortcut:
class ShortcutDemo {
function &__get($name) {
// Usually you want to make sure the method
// exists using method_exists, but for sake
// of simplicity of this demo, I will omit
// that logic.
return call_user_method('get'.$name, $this);
}
function __set($name, &$value) {
return call_user_method('set'.$name, $this, $value);
}
private $_Name;
function &getName() { return $this->_Name; }
function setName(&$value) { $this->_Name = $value; }
}
That way you can continue using your getters and setters to validate and set your data, and still use the syntactic shortcuts as such:
$shortcut->Name = 'Hello';
Another method that Andrew didn't mention (or hasn't mentioned at the time of writing) is for getting rid of getters and setters. Instead of having to declare each setter and getter like this:
$obj->setName("Chacha");
$obj->setRep(10000000000000000000000);
You can instead just do
$obj->Name = "chacha";
$obj->Rep = 100000000000000000;
The second method is more natural.
Magic Methods basically further the thought of Object Oriented programming, and the idea that how you implement a job should not matter to the outside world. Through Magic Methods, it allows you to store your variables however you want, and just let other classes set them in a natural way.
Example: I could store all my user's account preferences in a single array that would make it really easy to iterate through to push it all up to the session.
If I didn't use a Magic Method for this, I would either have to make a bunch of sets or gets, which means writing more code, or allow direct access to the array, which reveals the implementation, so I can't go and change it later.
Instead, using Magic Methods, I just have them set the variable regularly, and I deal with it internally.
You could use it for cases when a class has complex rules for isset and unset. For example, a class containing a variable $a could be an array of objects or other resources, and when unset, they have to do perform some other functionalities.
Though I am not sure why they allow the adding of a new property and retrieving of a non-private property, but you could use it to change the internal state of an object by calling other code depending on the name of the property/member variable being set.
In some cases, this resembles operator overloading in C++
Message forwarding for when you have composed or aggregated objects where polymorphism isn't an option (say, you're using a library class you can't control).
<?php
// Class A is final, so we can't make subclasses.
final class A
{
public function hello( $callback )
{
echo call_user_func( $callback, 'hello world' );
}
}
// so instead, we make a wrapper class that will take an instance
// of A as an aggregate
class B
{
private $a;
public function __construct( A $a )
{
$this->a = $a;
}
// this mimics inheritance on the aggregate object
// method calls are automatically forwarded to instance of A
// if they are valid
public function __call( $method, $args )
{
if ( method_exists( $this->a, $method ) )
{
return call_user_func_array( array( $this->a, $method ), $args );
}
throw new Exception( "Method [$method] not found." );
}
}
class C extends B
{
// This mimics overriding an "inherited" method
public function hello( $callback )
{
echo call_user_func( $callback, 'bonjour le monde' );
}
}
$a = new A;
$b = new B( $a );
$c = new C( $a );
$b->hello( 'strtoupper' );
$c->hello( 'strtoupper' );
This feature is actually what object oriented programming is all about, in the mind of its inventor Alan Kay: Objects sending each other messages, and potentially reacting to any kind of message. Methods fixed at compile time are a limited (but also more efficient) implementation of this concept. That's where Kay's famous-quote "I invented the term object oriented, and I can tell you that C++ wasn't what I had in mind." comes from.
Basically, allowing objects to react to method calls without having a corresponding method fixed at compile time implements this original, broader definition of object orientation. Most modern "dynamic" languages support it in one form or another.
As for what it's good for: take a look at Groovy's Builders for a good example. Basically, it allows very compact low-redundancy syntax by turning method names themselves into data.
One way, which is quite a bit fancier, that I've used it is to create a Linq like Object Relational Management (ORM) system. Where you can then load up a database table structure and manipulated the data (from the database table) as if it were just an object.
i.e.
include('blibrary/bLinq.class.inc');
$linq = new bLinq(new bLinqSql('mysql://dsn'));
$r = $linq->from('Users')
->password
->select();
which translates to the following SQL:
SELECT `password` from Users;
The password in the select statement comes from the overloaded method.
The result can be used like:
(array)$r->password; // which outputs an array multiple results of password;
(string)$r->password; // which outputs a string of the first password hash;
$r->password[2]; // which outputs a string of the third password hash;
The point is that the word "password" could be substituted for any other field in the database on the fly when programming.
I use __get and __set to link objects together e.g.
$user = new User();
echo $user->Profile->views;
This (usually) calls some SQL linking users.id = profile.user_id.
Properties (like that in Python or C#). For example when you use something like this in Nette, you create some class, which shows some property as public:
<?php
class Foo extends Object
{
public $bar;
}
You can access this property natural way – $instance->bar. But when you want to do some validation etc., you just add getter and setter:
<?php
class Foo extends Object
{
private $bar;
public function getBar()
{
return $this->bar;
}
public function setBar($bar)
{
if ($bar === NULL) throw new Exception('…');
$this->bar = $bar;
}
}
And still you use $instance->bar. But when you do $instance->bar = NULL;, it's like calling $instance->setBar(NULL);.

Is this a reasonable way to handle getters/setters in a PHP class?

I'm going to try something with the format of this question and I'm very open to suggestions about a better way to handle it.
I didn't want to just dump a bunch of code in the question so I've posted the code for the class on refactormycode.
base class for easy class property handling
My thought was that people can either post code snippets here or make changes on refactormycode and post links back to their refactorings. I'll make upvotes and accept an answer (assuming there's a clear "winner") based on that.
At any rate, on to the class itself:
I see a lot of debate about getter/setter class methods and is it better to just access simple property variables directly or should every class have explicit get/set methods defined, blah blah blah. I like the idea of having explicit methods in case you have to add more logic later. Then you don't have to modify any code that uses the class. However I hate having a million functions that look like this:
public function getFirstName()
{
return $this->firstName;
}
public function setFirstName($firstName)
{
return $this->firstName;
}
Now I'm sure I'm not the first person to do this (I'm hoping that there's a better way of doing it that someone can suggest to me).
Basically, the PropertyHandler class has a __call magic method. Any methods that come through __call that start with "get" or "set" are then routed to functions that set or retrieve values into an associative array. The key into the array is the name of the calling method after getting or setting. So, if the method coming into __call is "getFirstName", the array key is "FirstName".
I liked using __call because it will automatically take care of the case where the subclass already has a "getFirstName" method defined. My impression (and I may be wrong) is that the __get & __set magic methods don't do that.
So here's an example of how it would work:
class PropTest extends PropertyHandler
{
public function __construct()
{
parent::__construct();
}
}
$props = new PropTest();
$props->setFirstName("Mark");
echo $props->getFirstName();
Notice that PropTest doesn't actually have "setFirstName" or "getFirstName" methods and neither does PropertyHandler. All that's doing is manipulating array values.
The other case would be where your subclass is already extending something else. Since you can't have true multiple inheritances in PHP, you can make your subclass have a PropertyHandler instance as a private variable. You have to add one more function but then things behave in exactly the same way.
class PropTest2
{
private $props;
public function __construct()
{
$this->props = new PropertyHandler();
}
public function __call($method, $arguments)
{
return $this->props->__call($method, $arguments);
}
}
$props2 = new PropTest2();
$props2->setFirstName('Mark');
echo $props2->getFirstName();
Notice how the subclass has a __call method that just passes everything along to the PropertyHandler __call method.
Another good argument against handling getters and setters this way is that it makes it really hard to document.
In fact, it's basically impossible to use any sort of document generation tool since the explicit methods to be don't documented don't exist.
I've pretty much abandoned this approach for now. It was an interesting learning exercise but I think it sacrifices too much clarity.
The way I do it is the following:
class test {
protected $x='';
protected $y='';
function set_y ($y) {
print "specific function set_y\n";
$this->y = $y;
}
function __call($function , $args) {
print "generic function $function\n";
list ($name , $var ) = split ('_' , $function );
if ($name == 'get' && isset($this->$var)) {
return $this->$var;
}
if ($name == 'set' && isset($this->$var)) {
$this->$var= $args[0];
return;
}
trigger_error ("Fatal error: Call to undefined method test::$function()");
}
}
$p = new test();
$p->set_x(20);
$p->set_y(30);
print $p->get_x();
print $p->get_y();
$p->set_z(40);
Which will output (line breaks added for clarity)
generic function set_x
specific function set_y
generic function get_x
20
generic function get_y
30
generic function set_z
Notice: Fatal error: Call to undefined method set_z() in [...] on line 16
#Brian
My problem with this is that adding "more logic later" requires that you add blanket logic that applies to all properties accessed with the getter/setter or that you use if or switch statements to evaluate which property you're accessing so that you can apply specific logic.
That's not quite true. Take my first example:
class PropTest extends PropertyHandler
{
public function __construct()
{
parent::__construct();
}
}
$props = new PropTest();
$props->setFirstName("Mark");
echo $props->getFirstName();
Let's say that I need to add some logic for validating FirstNames. All I have to do is add a setFirstName method to my subclass and that method is automatically used instead.
class PropTest extends PropertyHandler
{
public function __construct()
{
parent::__construct();
}
public function setFirstName($name)
{
if($name == 'Mark')
{
echo "I love you, Mark!";
}
}
}
I'm just not satisfied with the limitations that PHP has when it comes to implicit accessor methods.
I agree completely. I like the Python way of handling this (my implementation is just a clumsy rip-off of it).
Yes that's right the variables have to be manually declared but i find that better since I fear a typo in the setter
$props2->setFristName('Mark');
will auto-generate a new property (FristName instead of FirstName) which will make debugging harder.
I like having methods instead of just using public fields, as well, but my problem with PHP's default implementation (using __get() and __set()) or your custom implementation is that you aren't establishing getters and setters on a per-property basis. My problem with this is that adding "more logic later" requires that you add blanket logic that applies to all properties accessed with the getter/setter or that you use if or switch statements to evaluate which property you're accessing so that you can apply specific logic.
I like your solution, and I applaud you for it--I'm just not satisfied with the limitations that PHP has when it comes to implicit accessor methods.
#Mark
But even your method requires a fresh declaration of the method, and it somewhat takes away the advantage of putting it in a method so that you can add more logic, because to add more logic requires the old-fashioned declaration of the method, anyway. In its default state (which is where it is impressive in what it detects/does), your technique is offering no advantage (in PHP) over public fields. You're restricting access to the field but giving carte blanche through accessor methods that don't have any restrictions of their own. I'm not aware that unchecked explicit accessors offer any advantage over public fields in any language, but people can and should feel free to correct me if I'm wrong.
I've always handled this issue in a similar with a __call which ends up pretty much as boiler plate code in many of my classes. However, it's compact, and uses the reflection classes to only add getters / setters for properties you have already set (won't add new ones). Simply adding the getter / setter explicitly will add more complex functionality. It expects to be
Code looks like this:
/**
* Handles default set and get calls
*/
public function __call($method, $params) {
//did you call get or set
if ( preg_match( "|^[gs]et([A-Z][\w]+)|", $method, $matches ) ) {
//which var?
$var = strtolower($matches[1]);
$r = new ReflectionClass($this);
$properties = $r->getdefaultProperties();
//if it exists
if ( array_key_exists($var,$properties) ) {
//set
if ( 's' == $method[0] ) {
$this->$var = $params[0];
}
//get
elseif ( 'g' == $method[0] ) {
return $this->$var;
}
}
}
}
Adding this to a class where you have declared default properties like:
class MyClass {
public $myvar = null;
}
$test = new MyClass;
$test->setMyvar = "arapaho";
echo $test->getMyvar; //echos arapaho
The reflection class may add something of use to what you were proposing. Neat solution #Mark.
Just recently, I also thought about handling getters and setters the way you suggested (the second approach was my favorite, i.e. the private $props array), but I discarded it for it wouldn't have worked out in my app.
I am working on a rather large SoapServer-based application and the soap interface of PHP 5 injects the values that are transmitted via soap directly into the associated class, without bothering about existing or non-existing properties in the class.
I can't help putting in my 2 cents...
I have taken to using __get and __set in this manor http://gist.github.com/351387 (similar to the way that doctrine does it), then only ever accessing the properties via the $obj->var in an outside of the class. That way you can override functionality as needed instead of making a huge __get or __set function, or overriding __get and __set in the child classes.

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