从类内部调用全局变量函数的正确语法是什么？

Question

I'm trying to call a global function from within a class. The name of the function is contained in one of the public properties of the class. I'm running into a small syntax problem that I have managed to work around, but I consider the work-around (an intermediary variable) inelegant and am looking for a more proper way to do this.

Consider the following code snippet:

class Foo {

  public $theFuncName = '';

  public function bar () {
    if ($this->theFuncName != '') {
      $theFuncName = $this->theFuncName;
      $theFuncName ();
    }
  }

}

function myGlobalFunc () {
  echo "This is myGlobalFunc\n";
}

$foo = new Foo ();
$foo->theFuncName = 'myGlobalFunc';
$foo->bar ();

I'm using the intermediary variable $theFuncName in bar() because directly referring to $this->theFuncName() implies that class Foo contains a method theFuncName , which is not the case.

What is the proper syntax to call the function referred to by the contents of $this->theFuncName without an intermediary variable?

Answer 1

Use call_user_func() :

class Foo 
{
    public $theFuncName = '';

    public function bar () 
    {
        if (is_callable($this->theFuncName)) {
            call_user_func($this->theFuncName);
        }
    }
}

For reference, see

• http://php.net/manual/en/function.is-callable.php
• http://php.net/manual/en/function.call-user-func.php