reflection.md

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Reflection

What reflection abilities are supported?

PHP

PHP will automatically use inspection at runtime to determine, for example, if an object being called has a particular method implemented, or that a particular object's method exists if it is being called.

Python

Python has several inspection methods built natively into the language. These include:

• callable(): returns True if the provided object can be called.
• type(): returns the type of the object provided.
• isinstance: takes two objects as arguments, and will return True if the first object provided is an instance of the second.
• dir: returns a list of valid attributes for a provided object.
• getattr(): attempts to return the value of a provided attribute from a provided object

How is reflection used?

PHP

By use of a ReflectionClass object. You may pass an object's name to an object of this type at creation time to allow inspection of various attributes or conditions of a class. For example, the following will provide a list of available methods for a class called myClass:

<?php
    class myClass {
        function foo() {
            print "Foo method";
        }
        function bar($baz) {
            print "Bar method";
        }
    }

    $reflector = new ReflectionClass('myClass');
    var_dump($reflector->getMethods());
?>

will yield:

array(2) { 
    [0]=> object(ReflectionMethod)#3 (2) {
        ["name"]=> string(3) "foo" 
        ["class"]=> string(7) "myClass" 
    }
    [1]=> object(ReflectionMethod)#4 (2) {
        ["name"]=> string(3) "bar" 
        ["class"]=> string(7) "myClass" 
    }
}

Python

Various object details can be determined by using the above described and linked reflection method programmatically. For example, to see if an object is an instance of a given class:

class myClass:
    def foo(self):
        print("foo")

a = myClass()

>>>print(isInstance(a, myClass))
True