Anonymous class construction

问题

I need an idea to create anonymous class on PHP. I don't know how I can works.

See my limitations:

On PHP you can't make anonymous class, like anonymous function (like class {});
On PHP you don't have class scope (except in namespaces, but it have the same problem below);
On PHP you can't use variables to specify the class name (like class $name {});
I don't have access to install the runkit PECL.

What I need, and why:

Well, I need create a function called ie create_class() that receives a key name and a anonymous class. It'll be useful for me because I want use different name class symbols that PHP can't accept. For instance:

<?php

  create_class('it.is.an.example', function() {
    return class { ... }
  });

  $obj = create_object('it.is.an.example');

?>

So, I need an idea that accept this use. I need it because on my framework I have this path: /modules/site/_login/models/path/to/model.php. So, the model.php need to declare a new class called site.login/path.to.model.

On call create_object() if the internal cache have a $class definition (like it.is.an.example it simply return the new class object. If not, need load. So I will use the $class content to search fastly what is the class file.

回答1:

In PHP 7.0 there will be anonymous classes. I don't fully understand your question, but your create_class() function might look like this:

function create_class(string $key, array &$repository) {
    $obj = new class($key) {
        private $key;
        function __construct($key) {
            $this->key = $key;
        }
    };
    $repository[$key] = $obj;
    return $obj;
}

This will instantiate an object with an anonymous class type and register it into the $repository. To get an object out you use the key you created it with: $repository['it.is.an.example'].

回答2:

You can create a dummy class using stdClass

$the_obj = new stdClass();

回答3:

So basically you want to implement a factory pattern.

Class Factory() {
  static $cache = array();

  public static getClass($class, Array $params = null) {
    // Need to include the inc or php file in order to create the class
    if (array_key_exists($class, self::$cache) {
      throw new Exception("Class already exists");
    }

    self::$cache[$class] = $class;
    return new $class($params);
  }
}

public youClass1() {
  public __construct(Array $params = null) {
     ...
  }
}

Add a cache within to check for duplicates

回答4:

If you really need to to that, you could use eval()

$code = "class {$className} { ... }";
eval($code);
$obj = new $className ();

But the gods won't approve this. You will go to hell if you do it.

来源：https://stackoverflow.com/questions/9726396/anonymous-class-construction

标签

php

class

namespaces

anonymous

php-7