How would I go about ensuring that the overridden parent method exists before I call it?
I've tried this:
public function func() {
if (function_exists('parent::func')) {
return parent::func();
}
}
However the function_exists never evaluates to true.
public function func()
{
if (is_callable('parent::func')) {
parent::func();
}
}
I use this for calling parent constructor if exists, works fine.
I also use the following as a generic version:
public static function callParentMethod(
$object,
$class,
$methodName,
array $args = []
) {
$parentClass = get_parent_class($class);
while ($parentClass) {
if (method_exists($parentClass, $methodName)) {
$parentMethod = new \ReflectionMethod($parentClass, $methodName);
return $parentMethod->invokeArgs($object, $args);
}
$parentClass = get_parent_class($parentClass);
}
}
use it like this:
callParentMethod($this, __CLASS__, __FUNCTION__, func_get_args());
The way to do that, is:
if (method_exists(get_parent_class($this), 'func')) {
// method exist
} else {
// doesn't
}
http://php.net/manual/en/function.method-exists.php
http://php.net/manual/en/function.get-parent-class.php
<?php
class super {
public function m() {}
}
class sub extends super {
public function m() {
$rc = new ReflectionClass(__CLASS__);
$namepc = $rc->getParentClass()->name;
return method_exists($namepc, __FUNCTION__);
}
}
$s = new sub;
var_dump($s->m());
gives bool(true). Not sure if this would work if the method was defined in a superclass of super, but it would be a matter of introducing a simple loop.
Related
I have two classes, ClassA, ClassB. In ClassA I have Method which call method from ClassB.
For Example:
function functionInClassB($state)
{
if ($state) {
return true;
} else {
return false;
}
}
function functionInClassA ()
{
if (functionInClassB(1)) {
return "Anything";
}
}
Now, I want test functionInClassB with PhpUnit and I dont want functionInClassB ran. I want return value which I want.
Sorry for my English, please help!!!
Old question, but I think you're referring to stubbing / mocking.
How easy /sensible it is depends. If you want to call functionInClassB statically then you're out of luck; static stuff doesn't work well with testing. But if you're calling the method on an instance then the following should work:
class A {
protected $instanceOfB;
public function functionInClassA(B $injectedInstanceOfB) {
if ($injectedInstanceOfB->functionInClassB(1)) return 'anything';
}
}
class B {
public function functionInClassB($state) {
if ($state) {
return true;
} else {
return false;
}
}
}
class yourPHPUnitTest extends \PHPUnit\Framework\TestCase {
public function testA() {
$stubOfB = $this->createStub(\B::class);
// Optionally...
$stubOfB->method('functionInClassB')->willReturn('something');
// Thing you want to test
$a = new A();
$result = $a->functionInClassA($stubOfB);
$this->assertEqual('something', $result);
}
}
I understand that one can use interfaces to mandate the definition of a function, but I cannot find something that enables one to mandate function calls, such that e.g. if I create a class being a member of another class (via extends, etc), with a function, for that class to automatically ensure that mandatory functions are called in part with that function.
I mean, to clarify further:
class domain {
function isEmpty($input) {
//apply conditional logic and results
}
}
class test extends domain {
function addTestToDBTable($test) {
/**
* try to add but this class automatically makes it so that all rules of
* class domain must be passed before it can run
* - so essentially, I am no longer required to call those tests for each and
* every method
**/
}
}
Apologies if this appears incoherent by any means. Sure, it seems lazy but I want to be able to force context without having to concern abou
Update:
Okay, to clarify further: in PHP, if I extend and declare a __construct() for a child class, that child class will override the parent __construct(). I do not want this, I want the parent construct to remain and mandate whatever as it pleases just as the child class may do so also.
I guess it can be done in two different ways.
Aspect Oriented Programming
Have a look here https://github.com/AOP-PHP/AOP
Generate or write Proxy classes
A really simple example could be:
<?php
class A {
public function callMe() {
echo __METHOD__ . "\n";
}
}
class B extends A {
// prevents instantiation
public function __construct() {
}
public function shouldCallMe() {
echo __METHOD__ . "\n";
}
public static function newInstance() {
return new ABProxy();
}
}
class ABProxy {
private $b;
public function __construct() {
$this->b = new B();
}
public function __call($method, $args) {
$this->b->callMe();
return call_user_func_array(array($this->b, $method), $args);
}
}
// make the call
$b = B::newInstance();
$b->shouldCallMe();
// Outputs
// ------------------
// A::callMe
// B::shouldCallMe
Hopes this helps a bit.
Sounds like you want a Decorator.
See This answer for a detailed explanation on how to do it. Note that it does not require a class extension.
I would use a domain-validating decorator with some doc-block metaprogramming magic. But this is really a job for an entire library, which no doubt exists.
fiddle
<?php
class FooDomain {
public static function is_not_empty($input) {
return !empty($input);
}
}
class Foo {
/**
* #domain FooDomain::is_not_empty my_string
*/
public function print_string($my_string) {
echo $my_string . PHP_EOL;
}
}
$foo = new DomainValidator(new Foo());
$foo->print_string('Hello, world!');
try {
$foo->print_string(''); // throws a DomainException
} catch (\DomainException $e) {
echo 'Could not print an empty string...' . PHP_EOL;
}
// ---
class DomainValidator {
const DOMAIN_TAG = '#domain';
private $object;
public function __construct($object) {
$this->object = $object;
}
public function __call($function, $arguments) {
if (!$this->verify_domain($function, $arguments)) {
throw new \DomainException('Bad domain!');
}
return call_user_func_array(
array($this->object, $function),
$arguments
);
}
public function __get($name) {
return $this->object->name;
}
public function __set($name, $value) {
$this->object->name = $value;
}
private function verify_domain($function, $arguments) {
// Get reference to method
$method = new \ReflectionMethod($this->object, $function);
$domains = $this->get_domains($method->getDocComment());
$arguments = $this->parse_arguments(
$method->getParameters(),
$arguments
);
foreach ($domains as $domain) {
if (!call_user_func(
$domain['name'],
$arguments[$domain['parameter']]
)) {
return false;
}
}
return true;
}
private function get_domains($doc_block) {
$lines = explode("\n", $doc_block);
$domains = array();
$domain_tag = DomainValidator::DOMAIN_TAG . ' ';
foreach ($lines as $line) {
$has_domain = stristr($line, $domain_tag) !== false;
if ($has_domain) {
$domain_info = explode($domain_tag, $line);
$domain_info = explode(' ', $domain_info[1]);
$domains[] = array(
'name' => $domain_info[0],
'parameter' => $domain_info[1],
);
}
}
return $domains;
}
private function parse_arguments($parameters, $values) {
$ret = array();
for ($i = 0, $size = sizeof($values); $i < $size; $i++) {
$ret[$parameters[$i]->name] = $values[$i];
}
return $ret;
}
}
Output:
Hello, world!
Could not print an empty string...
PHP calls private method in parent class instead of method define in current class called by call_user_func
class Car {
public function run() {
return call_user_func(array('Toyota','getName')); // should call toyota
}
private static function getName() {
return 'Car';
}
}
class Toyota extends Car {
public static function getName() {
return 'Toyota';
}
}
$car = new Car();
echo $car->run(); //Car instead of Toyota
$toyota = new Toyota();
echo $toyota->run(); //Car instead of Toyota
I have found a solution with a different approach..
<?php
class Car {
public static function run() {
return static::getName();
}
private static function getName() {
return 'Car';
}
}
class Toyota extends Car {
public static function getName() {
return 'Toyota';
}
}
echo Car::run();
echo Toyota::run();
?>
Using Late Static Binding..
You might use something like this:
<?php
class Car {
public function run() {
return static::getName();
}
private static function getName(){
return 'Car';
}
}
class Toyota extends Car {
public static function getName(){
return 'Toyota';
}
}
$car = new Car();
echo $car->run();
echo PHP_EOL;
$toyota = new Toyota();
echo $toyota->run();
?>
Output:
Car
Toyota
PHP 5.4.5
This is a bug that appears to have fluctuated in and out of existence for a long time (see #deceze's tests in comments on the question). It is possible to "fix" this issue - that is, give consistent behaviour across PHP versions - using reflection:
Works in PHP 5.3.2 and later due to a dependency on ReflectionMethod::setAccessible() to invoke private/protected methods. I will add further explanation for this code, what it can and can't do and how it works very shortly.
Unfortunately it's not possible to test this directly on 3v4l.org because the code is too large, however this is the first ever real use case for minifying PHP code - it does work on 3v4l if you do this, so feel free to play around and see if you can break it. The only issue I'm aware of is that it doesn't currently understand parent. It is also restricted by the lack of $this support in closures before 5.4, there's not really anything that can be done about this though.
<?php
function call_user_func_fixed()
{
$args = func_get_args();
$callable = array_shift($args);
return call_user_func_array_fixed($callable, $args);
}
function call_user_func_array_fixed($callable, $args)
{
$isStaticMethod = false;
$expr = '/^([a-z_\x7f-\xff][\w\x7f-\xff]*)::([a-z_\x7f-\xff][\w\x7f-\xff]*)$/i';
// Extract the callable normalized to an array if it looks like a method call
if (is_string($callable) && preg_match($expr, $callable, $matches)) {
$func = array($matches[1], $matches[2]);
} else if (is_array($callable)
&& count($callable) === 2
&& isset($callable[0], $callable[1])
&& (is_string($callable[0]) || is_object($callable[0]))
&& is_string($callable[1])) {
$func = $callable;
}
// If we're not interested in it use the regular mechanism
if (!isset($func)) {
return call_user_func_array($func, $args);
}
$backtrace = debug_backtrace(); // passing args here is fraught with complications for backwards compat :-(
if ($backtrace[1]['function'] === 'call_user_func_fixed') {
$called = 'call_user_func_fixed';
$contextKey = 2;
} else {
$called = 'call_user_func_array_fixed';
$contextKey = 1;
}
try {
// Get a reference to the target static method if possible
switch (true) {
case $func[0] === 'self':
case $func[0] === 'static':
if (!isset($backtrace[$contextKey]['object'])) {
throw new Exception('Use of self:: in an invalid context');
}
$contextClass = new ReflectionClass($backtrace[$contextKey][$func[0] === 'self' ? 'class' : 'object']);
$contextClassName = $contextClass->getName();
$method = $contextClass->getMethod($func[1]);
$ownerClassName = $method->getDeclaringClass()->getName();
if (!$method->isStatic()) {
throw new Exception('Attempting to call instance method in a static context');
}
$invokeContext = null;
if ($method->isPrivate()) {
if ($ownerClassName !== $contextClassName
|| !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call private method in an invalid context');
}
$method->setAccessible(true);
} else if ($method->isProtected()) {
if (!method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call protected method in an invalid context');
}
while ($contextClass->getName() !== $ownerClassName) {
$contextClass = $contextClass->getParentClass();
}
if ($contextClass->getName() !== $ownerClassName) {
throw new Exception('Attempting to call protected method in an invalid context');
}
$method->setAccessible(true);
}
break;
case is_object($func[0]):
$contextClass = new ReflectionClass($func[0]);
$contextClassName = $contextClass->getName();
$method = $contextClass->getMethod($func[1]);
$ownerClassName = $method->getDeclaringClass()->getName();
if ($method->isStatic()) {
$invokeContext = null;
if ($method->isPrivate()) {
if ($ownerClassName !== $contextClassName || !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call private method in an invalid context');
}
$method->setAccessible(true);
} else if ($method->isProtected()) {
if (!method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call protected method in an invalid context');
}
while ($contextClass->getName() !== $ownerClassName) {
$contextClass = $contextClass->getParentClass();
}
if ($contextClass->getName() !== $ownerClassName) {
throw new Exception('Attempting to call protected method in an invalid context');
}
$method->setAccessible(true);
}
} else {
$invokeContext = $func[0];
}
break;
default:
$contextClass = new ReflectionClass($backtrace[$contextKey]['object']);
$method = new ReflectionMethod($func[0], $func[1]);
$ownerClassName = $method->getDeclaringClass()->getName();
if (!$method->isStatic()) {
throw new Exception('Attempting to call instance method in a static context');
}
$invokeContext = null;
if ($method->isPrivate()) {
if (empty($backtrace[$contextKey]['object'])
|| $func[0] !== $contextClass->getName()
|| !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call private method in an invalid context');
}
$method->setAccessible(true);
} else if ($method->isProtected()) {
$contextClass = new ReflectionClass($backtrace[$contextKey]['object']);
if (empty($backtrace[$contextKey]['object']) || !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call protected method outside a class context');
}
while ($contextClass->getName() !== $ownerClassName) {
$contextClass = $contextClass->getParentClass();
}
if ($contextClass->getName() !== $ownerClassName) {
throw new Exception('Attempting to call protected method in an invalid context');
}
$method->setAccessible(true);
}
break;
}
// Invoke the method with the passed arguments and return the result
return $method->invokeArgs($invokeContext, $args);
} catch (Exception $e) {
trigger_error($called . '() expects parameter 1 to be a valid callback: ' . $e->getMessage(), E_USER_ERROR);
return null;
}
}
Use "protected" modifier if you want to get access from parent and descendants only. IMO, it's obvious. For example:
<?php
class Car {
public function run() {
return call_user_func(array('static','getName'));
}
protected static function getName() {
return 'Car';
}
}
class Toyota extends Car {
protected static function getName() {
return 'Toyota';
}
}
$car = new Car();
echo $car->run(); // "Car"
$toyota = new Toyota();
echo $toyota->run(); // "Toyota"
You can use get_called_class() instead of 'static'.
The problem is, I think, with the different access levels of the two getname functions. If you make the base class version of getname() public (the same as the derived class version), then in php 5.3.15 (on my Mac), you get Toyota. I think that, because of the different access levels, you end up with two different versions of the getname() function in the Toyota class, rather than the derived class version overriding the base class version. In other words, you have overloading rather than overriding. Therefore, when the run() function looks for a getname() function in the Toyota class to execute, it finds two and takes the first one, which would be the first to be declared (from the base class).
Granted this is just supposition on my part, but it sounds plausible.
use the get_called_called function todo this
public function run() {
$self = get_called_class();
return $self::getName();
}
I believe you're functions are overriding each other and by default going to the first one. Unless you change the parameters of one function, or rename the function it will always default to the parent class function.
I'm trying to add methods dynamically from external files.
Right now I have __call method in my class so when i call the method I want, __call includes it for me; the problem is I want to call loaded function by using my class, and I don't want loaded function outside of the class;
Class myClass
{
function__call($name, $args)
{
require_once($name.".php");
}
}
echoA.php:
function echoA()
{
echo("A");
}
then i want to use it like:
$myClass = new myClass();
$myClass->echoA();
Any advice will be appreciated.
Is this what you need?
$methodOne = function ()
{
echo "I am doing one.".PHP_EOL;
};
$methodTwo = function ()
{
echo "I am doing two.".PHP_EOL;
};
class Composite
{
function addMethod($name, $method)
{
$this->{$name} = $method;
}
public function __call($name, $arguments)
{
return call_user_func($this->{$name}, $arguments);
}
}
$one = new Composite();
$one -> addMethod("method1", $methodOne);
$one -> method1();
$one -> addMethod("method2", $methodTwo);
$one -> method2();
You cannot dynamically add methods to a class at runtime, period.*
PHP simply isn't a very duck-punchable language.
* Without ugly hacks.
You can dynamically add attributes and methods providing it is done through the constructor in the same way you can pass a function as argument of another function.
class Example {
function __construct($f)
{
$this->action=$f;
}
}
function fun() {
echo "hello\n";
}
$ex1 = new class('fun');
You can not call directlry $ex1->action(), it must be assigned to a variable and then you can call this variable like a function.
if i read the manual right,
the __call get called insted of the function, if the function dosn't exist
so you probely need to call it after you created it
Class myClass
{
function __call($name, $args)
{
require_once($name.".php");
$this->$name($args);
}
}
You can create an attribute in your class : methods=[]
and use create_function for create lambda function.
Stock it in the methods attribute, at index of the name of method you want.
use :
function __call($method, $arguments)
{
if(method_exists($this, $method))
$this->$method($arguments);
else
$this->methods[$method]($arguments);
}
to find and call good method.
What you are referring to is called Overloading. Read all about it in the PHP Manual
/**
* #method Talk hello(string $name)
* #method Talk goodbye(string $name)
*/
class Talk {
private $methods = [];
public function __construct(array $methods) {
$this->methods = $methods;
}
public function __call(string $method, array $arguments): Talk {
if ($func = $this->methods[$method] ?? false) {
$func(...$arguments);
return $this;
}
throw new \RuntimeException(sprintf('Missing %s method.'));
}
}
$howdy = new Talk([
'hello' => function(string $name) {
echo sprintf('Hello %s!%s', $name, PHP_EOL);
},
'goodbye' => function(string $name) {
echo sprintf('Goodbye %s!%s', $name, PHP_EOL);
},
]);
$howdy
->hello('Jim')
->goodbye('Joe');
https://3v4l.org/iIhph
You can do both adding methods and properties dynamically.
Properties:
class XXX
{
public function __construct($array1)
{
foreach ($array1 as $item) {
$this->$item = "PropValue for property : " . $item;
}
}
}
$a1 = array("prop1", "prop2", "prop3", "prop4");
$class1 = new XXX($a1);
echo $class1->prop1 . PHP_EOL;
echo $class1->prop2 . PHP_EOL;
echo $class1->prop3 . PHP_EOL;
echo $class1->prop4 . PHP_EOL;
Methods:
//using anounymous function
$method1 = function () {
echo "this can be in an include file and read inline." . PHP_EOL;
};
class class1
{
//build the new method from the constructor, not required to do it here by it is simpler.
public function __construct($functionName, $body)
{
$this->{$functionName} = $body;
}
public function __call($functionName, $arguments)
{
return call_user_func($this->{$functionName}, $arguments);
}
}
//pass the new method name and the refernce to the anounymous function
$myObjectWithNewMethod = new class1("method1", $method1);
$myObjectWithNewMethod->method1();
I've worked up the following code example and a helper method which works with __call which may prove useful. https://github.com/permanenttourist/helpers/tree/master/PHP/php_append_methods
In effect, if I have a class c and instances of $c1 and $c2
which might have different private variable amounts but all their public methods return the same values I would like to be able to check that $c1 == $c2?
Does anyone know an easy way to do this?
You can also implement a equal($other) function like
<?php
class Foo {
public function equals($o) {
return ($o instanceof 'Foo') && $o.firstName()==$this.firstName();
}
}
or use foreach to iterate over the public properties (this behaviour might be overwritten) of one object and compare them to the other object's properties.
<?php
function equalsInSomeWay($a, $b) {
if ( !($b instanceof $a) ) {
return false;
}
foreach($a as $name=>$value) {
if ( !isset($b->$name) || $b->$name!=$value ) {
return false;
}
}
return true;
}
(untested)
or (more or less) the same using the Reflection classes, see http://php.net/manual/en/language.oop5.reflection.php#language.oop5.reflection.reflectionobject
With reflection you might also implement a more duck-typing kind of comparision, if you want to, like "I don't care if it's an instance of or the same class as long as it has the same public methods and they return the 'same' values"
it really depends on how you define "equal".
It's difficult to follow exactly what you're after. Your question seems to imply that these public methods don't require arguments, or that if they did they would be the same arguments.
You could probably get quite far using the inbuilt reflection classes.
Pasted below is a quick test I knocked up to compare the returns of all the public methods of two classes and ensure they were they same. You could easily modify it to ignore non matching public methods (i.e. only check for equality on public methods in class2 which exist in class1). Giving a set of arguments to pass in would be trickier - but could be done with an array of methods names / arguments to call against each class.
Anyway, this may have some bits in it which could be of use to you.
$class1 = new Class1();
$class2 = new Class2();
$class3 = new Class3();
$class4 = new Class4();
$class5 = new Class5();
echo ClassChecker::samePublicMethods($class1,$class2); //should be true
echo ClassChecker::samePublicMethods($class1,$class3); //should be false - different values
echo ClassChecker::samePublicMethods($class1,$class4); //should be false -- class3 contains extra public methods
echo ClassChecker::samePublicMethods($class1,$class5); //should be true -- class5 contains extra private methods
class ClassChecker {
public static function samePublicMethods($class1, $class2) {
$class1methods = array();
$r = new ReflectionClass($class1);
$methods = $r->getMethods();
foreach($methods as $m) {
if ($m->isPublic()) {
#$result = call_user_method($m->getName(), $class1);
$class1methods[$m->getName()] = $result;
}
}
$r = new ReflectionClass($class2);
$methods = $r->getMethods();
foreach($methods as $m) {
//only comparing public methods
if ($m->isPublic()) {
//public method doesn't match method in class1 so return false
if(!isset($class1methods[$m->getName()])) {
return false;
}
//public method of same name doesn't return same value so return false
#$result = call_user_method($m->getName(), $class2);
if ($class1methods[$m->getName()] !== $result) {
return false;
}
}
}
return true;
}
}
class Class1 {
private $b = 'bbb';
public function one() {
return 999;
}
public function two() {
return "bendy";
}
}
class Class2 {
private $a = 'aaa';
public function one() {
return 999;
}
public function two() {
return "bendy";
}
}
class Class3 {
private $c = 'ccc';
public function one() {
return 222;
}
public function two() {
return "bendy";
}
}
class Class4 {
public function one() {
return 999;
}
public function two() {
return "bendy";
}
public function three() {
return true;
}
}
class Class5 {
public function one() {
return 999;
}
public function two() {
return "bendy";
}
private function three() {
return true;
}
}
You can define PHP's __toString magic method inside your class.
For example
class cat {
private $name;
public function __contruct($catname) {
$this->name = $catname;
}
public function __toString() {
return "My name is " . $this->name . "\n";
}
}
$max = new cat('max');
$toby = new cat('toby');
print $max; // echoes 'My name is max'
print $toby; // echoes 'My name is toby'
if($max == $toby) {
echo 'Woohoo!\n';
} else {
echo 'Doh!\n';
}
Then you can use the equality operator to check if both instances are equal or not.
HTH,
Rushi
George: You may have already seen this but it may help: http://usphp.com/manual/en/language.oop5.object-comparison.php
When using the comparison operator (==), object variables are compared in a simple manner, namely: Two object instances are equal if they have the same attributes and values, and are instances of the same class.
They don't get implicitly converted to strings.
If you want todo comparison, you will end up modifying your classes. You can also write some method of your own todo comparison using getters & setters
You can try writing a class of your own to plugin and write methods that do comparison based on what you define. For example:
class Validate {
public function validateName($c1, $c2) {
if($c1->FirstName == "foo" && $c2->LastName == "foo") {
return true;
} else if (// someother condition) {
return // someval;
} else {
return false;
}
}
public function validatePhoneNumber($c1, $c2) {
// some code
}
}
This will probably be the only way where you wont have to modify the pre-existing class code