PHP and MagicMethods - php

Question

I write some class to work with string like in C#.
Here it is:
class String {
private $origin_string = null;
private $result_string = null;
function __construct($string)
{
$this->origin_string = $string;
$this->result_string = $this->origin_string;
}
public function Trim()
{
$this->result_string = Trim($this->result_string);
return $this->result_string;
}
public function StartWith($string)
{
return (substr($this->result_string, 0, strlen($string)) === $string);
}
public function EndWith($string)
{
$endlen = strlen($string);
$strlen = strlen($this->result_string);
return (substr($this->result_string, $strlen - $endlen, $endlen) === $string);
}
public function Contains($string) {
return (strpos($this->result_string, $string) !== false);
}
public function Replace($search, $string) {
$this->result_string = str_replace($search, $string, $this->result_string);
return $this->result_string;
}
public function __invoke($string) {
$this->origin_string = $string;
$this->result_string = $this->origin_string;
return $this;
}
public function __toString()
{
return $this->result_string;
}
public static function Override($string)
{
return new self($string);
}
}
In use:
$s = new String("My custom string");
if ($s->StartWith("My"))
$s->Replace("custom", "super");
print $s; // "My super string"
To correct print my text from object i use magic method __toString().
Question:
Is there a method, the inverse __toString?
That is so we can write:
$s = "new text";
And the line is assigned to variables within the object.
($s - an existing object "String" in the example above.)
An analogue of the method __set, only in relation to the object, not the variable inside it.
While using the __invoke, but it's not quite what I want.

Answer 1

No.
$s = "new text"; assigns the (native PHP) string "new text" to the variable $s. It overwrites whatever $s was before. It does not call any methods on $s if $s is an object.
You'd have to alter the core behavior of PHP to achieve something like that. You'll always have to explicitly call a method on your String object.

Answer 2

The short answer to your direct question is "No, there isn't any way to do that in PHP".
Strings are a primitive data type in PHP, and it doesn't do operator overloading or any other other features you'd need to enable this kind of thing.
But also, because they're a primitive data type, there's no real need to encapsulate them in an object structure like this. PHP's OO capabilities have come a long way in recent versions, but at its heart it still isn't a fully OO language.
In fact, I'd say that what you're doing is counter productive. You're wrapping the concept of a string up into a class that has significantly less functionality than basic PHP. You're writing a whole stack of code in order to do stuff in one line of code that can already be done in one line of code, and you're limiting the ability to do a whole lot more.
For example, you've got Contains() and StartsWith() methods, but they don't deal with regular expressions in any way.
And how are you going to deal with concatenation? And what about embedding variables into strings?
PHP has a lot of string handling functionality (in fact, string handling it's one of its strengths), which your class isn't going to be able to replicate.
I recommend working with the language you've been given, not trying to force it to conform to your syntax ideals.

Answer 3

No, you can't assign directly a value to your object. PHP does not allow operator overloading and this style assignment. You must use the contructor, the invoke or any setter method to assign a new value to your string.

Answer 4

You can write something like this:
$s = 'myclass';
$o = new $s();
or, if you want to 'compile' the new keyword you could do:
$s = '$x = new myclass();';
eval($s);
hope this helps.