Home » Defining class methods in PHP

Defining class methods in PHP

Solutons:


No, as of PHP 5.2. However, you may use __call magic method to forward call to arbitrary function or method.

class A {

    public function __call($method, $args) {
        if ($method == 'foo') {
            return call_user_func_array('bar', $args);
        }
    }

}

function bar($x) {
    echo $x;
}

$a = new A();
$a->foo('12345'); // will result in calling bar('12345')

In PHP 5.4 there is support for traits. Trait is an implementation of method(s) that cannot be instantiated as standalone object. Instead, trait can be used to extend class with contained implementation. Learn more on Traits here.

Yes it is possible to add a method to a PHP class after it is defined. You want to use classkit, which is an “experimental” extension. It appears that this extension isn’t enabled by default however, so it depends on if you can compile a custom PHP binary or load PHP DLLs if on windows (for instance Dreamhost does allow custom PHP binaries, and they’re pretty easy to setup).

<?php
class A { }
classkit_method_add('A', 'bar', '$message', 'echo $message;', 
    CLASSKIT_ACC_PUBLIC); 
$a = new A();
$a->bar('Hello world!');

Example from the PHP manual:

<?php
class Example {
    function foo() {
        echo "foo!n";
    }
}

// create an Example object
$e = new Example();

// Add a new public method
classkit_method_add(
    'Example',
    'add',
    '$num1, $num2',
    'return $num1 + $num2;',
    CLASSKIT_ACC_PUBLIC
);

// add 12 + 4
echo $e->add(12, 4);

You could perhaps override __call or __callStatic to locate a missing method at runtime, but you’d have to make up your own system for locating and calling the code. For example, you could load a “Delegate” class to handle the method call.

Here’s an example – if you tried to call $foo->bar(), the class would attempt to create a FooDelegate_bar class, and call bar() on it with the same arguments. If you’ve got class auto-loading set up, the delegate can live in a separate file until required…

class Foo {

    public function __call($method, $args) {
        $delegate="FooDelegate_".$method;
        if (class_exists($delegate))
        {
             $handler=new $delegate($this);
             return call_user_func_array(array(&$handler, $method), $args);
        }


    }

}

Related Solutions

Calculate the sum with minimum usage of numbers

Here's a hint: 23 : 11 + 11+ 1 ( 3 magic numbers) 120: 110+ 10 (2 magic numbers) The highest digit in the target number is the answer, since you need exactly k magic numbers (all having 1 in the relevant position) in order for the sum to contain the digit k. So...

Why not drop the “auto” keyword? [duplicate]

Your proposal would be rejected on the basis of backward compatibility alone. But let's say for the sake of argument that the standards committee like your idea. You don't take into account the numerous ways you can initialize a variable widget w; // (a) widget...

Recursive to iterative using a systematic method [closed]

So, to restate the question. We have a function f, in our case fac. def fac(n): if n==0: return 1 else: return n*fac(n-1) It is implemented recursively. We want to implement a function facOpt that does the same thing but iteratively. fac is written almost in...

How can I match values in one file to ranges from another?

if the data file sizes are not huge, there is a simpler way $ join input1 input2 | awk '$5<$4 && $3<$5 {print $2, $5-$3+1}' B100002 32 B100043 15 B123465 3 This Perl code seems to solve your problem It is a common idiom: to load the entire...

Javascript difference between “=” and “===” [duplicate]

You need to use == or === for equality checking. = is the assignment operator. You can read about assignment operators here on MDN. As a quick reference as you are learning JS: = assignment operator == equal to === equal value and equal type != not equal !==...

Compiler complains about misplaced else [closed]

Your compiler complains about an misplaced else because, well, there is an else without a preceding if: // ... for (j=1; j<n-i; j++) { if(a[j]<=a[j+1]) { // ... } // END OF IF } // END OF FOR else { continue; } // ... The else in your code does not follow...

Bootstrap – custom alerts with progress bar

/* !important are just used to overide the bootstrap css in the snippet */ .alertContainer { border-radius: 0 !important; border-width: 0 !important; padding: 0 !important; height: auto !important; position: absolute !important; bottom: 15px !important; left:...

How to Garbage Collect an external Javascript load?

Yes, s.onload = null is useful and will garbage collect! As of 2019, it is not possible to explicitly or programmatically trigger garbage collection in JavaScript. That means it collects when it wants. Although there is cases where setting to null may do a GC...

Math programming with python

At first, what you are looking for is the modulo operator and the function math.floor() Modulo from wikipedia: In computing, the modulo operation finds the remainder after division of one number by another (sometimes called modulus). for example: 12%12=0...

Android slide over letters to create a word [closed]

Here some advice you can use: First for each cell you can create an object that represents the state of that cell: class Cell { char mChar; int row,column; boolean isSelected; } then you can create a 2D array of your cells Cell[][] mTable = ... For views you...

Sum two integers in Java

You reused the x and y variable names (hence the variable x is already defined in method main error), and forgot to assign the ints read from the Scanner to the x and y variables. Besides, there's no need to create two Scanner objects. public static void...

Extend three classes that implements an interface in Java

Using this simplified implementation of the library, using method() instead of M(): interface IFC { void method(); } class A implements IFC { public void method() { System.out.println("method in A"); }; } As akuzminykh mentions in their comment You'd write a...

How to set the stream content in PHPExcel? [closed]

Okey, First thing first PHPExcel_Worksheet_MemoryDrawing() can't solve your problem if you insist to use stream content and pass that to your worksheet your PDF will not render your image. But you can use `PHPExcel_Worksheet_Drawing()' if you want to render...