Suppose I've got a library class and an autoloader that includes any class that starts with MyLibrary_ from the classes directory:

spl_autoload_register(
    function ($classname) {

        if(class_exists($classname)) return;

        if(strpos($classname, 'MyLibrary_') !== 0) return;

        //if such class exists, include it
        $class_file = __DIR__.'/classes/'.$classname.'.php';
        if(file_exists($class_file)){
            include $class_file;
        }
    }
);
if(!class_exists('Someprefix_MyLibrary')){
    class Someprefix_MyLibrary{}
}
$mylibrary = new Someprefix_MyLibrary;

Then, in the /classes/strings.php file there is a child class MyLibrary_strings:

class MyLibrary_strings extends Someprefix_MyLibrary{

   public punction __construct(){
       $this->strings = new self(); //not declared in parent class
   }

   //make first letter capital in a multi-byte string
    public function mb_ucfirst($string, $encoding){
        $firstChar = mb_substr($string, 0, 1, $encoding);
        $then = mb_substr($string, 1, null, $encoding);
        return mb_strtoupper($firstChar, $encoding) . $then;
    }
}

I would like to do something like:

$new_string = $mylibrary->strings->mb_ucfirst('somestring');

Unless I declare public $strings in parent class, my IDE warns me that a property has been declared dynamically, and in other child classes, the strings property will be marked as not found. What I want is to automatically include a parent property for each file that has been placed into the classes directory OR for every child class of Someprefix_MyLibrary, without having to manually declare every property.

Is it possible to do it, and how?

CodePudding user response：

You can achieve this using the __get magic method in php like so.

In your parent class, add a __get method:

class Someprefix_MyLibrary{
 
    public function __get(string $name)
    {
        return $this->{$name} = null;
    }
}

And call any undeclared property you need for example in your child class:

class MyLibrary_strings extends  Someprefix_MyLibrary{
 
    public function undeclaredProperty(){
        return $this->string;
    }

}

Note: Thus, when calling any undeclared property, we will fall into the __get magic method, where we will declare it and return it.

CodePudding user response：

Have you thought about using namespaces and static methods instead?

You would have to change your auto-loading, but something like:

// MyLibrary_Strings.php
namespace MyLibrary {
    class Strings {
        public static function mb_ucfirst($string, $encoding) {
            $firstChar = mb_substr($string, 0, 1, $encoding);
            $then = mb_substr($string, 1, null, $encoding);
            return mb_strtoupper($firstChar, $encoding) . $then;
        }
    }
}

// MyLibrary_Arrays.php
namespace MyLibrary {
    class Arrays {
        public static function first($array) {
            return $array[0];
        }
    }
}

// some other code
$result = MyLibrary\String::mb_ucfirst($string, $encoding);
$first_item = MyLibrary\Array::first(["a", "b", "c"]);