PHP string to object name.

Question

Ok I have a string...

$a_string = "Product";

and I want to use this string in a call to a object like this:

$this->$a_string->some_function();

How the dickens do I dynamically call that object?

(don't think Im on php 5 mind)

Answer 1

EDIT: You need to be running PHP5 in order to do any method chaining. After that, what you have is perfectly legal.

Answer 2

In the code you've shown, it looks like you're trying to call a function from string itself. My guess is that you want to call a function from a class with the same name as that string, in this case "Product."

This is what that would look like:

$this->Product->some_function();

It seems you might instead be looking for something like this:

$Product = new Product();
$Product->some_function();

Answer 3

Let's see if I got your intentions correctly...

$some_obj=$this->$a_string;
$some_obj->some_function();

Answer 4

So you the code you want to use would be:

$a_string = "Product";
$this->$a_string->some_function();

This code implies a few things. A class called Product with the method some_function(). $this has special meaning, and is only valid inside a class definition. So another class would have a member of Product class.

So to make your code legal, here's the code.

class Product {
    public function some_function() {
        print "I just printed Product->some_function()!";
    }
}

class AnotherClass {

    public $Product;

    function __construct() {
        $this->Product = new Product(); 
    }

    public function callSomeCode() {
        // Here's your code!
        $a_string = "Product";
        $this->$a_string->some_function();
    }
}

Then you can call it with this:

$MyInstanceOfAnotherClass = new AnotherClass();
$MyInstanceOfAnotherClass->callSomeCode();

Answer 5

So you've got an object, and one of it's properties (called "Product") is another object which has a method called some_function().

This works for me (in PHP5.3):

<?PHP


class Foo {
     var $bar;
}

class Bar {
      function some_func(){
           echo "hello!\n";
      }
}

$f = new Foo();
$f->bar = new Bar();

$str = 'bar';

$f->$str->some_func(); //echos "hello!"

I don't have PHP4 around, but if it doesn't work there, you might need to use call_user_func() (or call_user_func_array() if you need to pass arguments to some_function()

Answer 6

I seem to have read this question differently from everyone else who's responded, but are you trying to use variable variables?