在php类中动态创建方法，以便可以访问$ this

Question

I have a class that executes eval statements within a (very large) loop. The eval statements are database stored code (mixed html & php) that needs to be processed. There is however is a serious performance issue because of this.

Instead of parsing the eval-statement every time in the loop, I would like to create a dynamic methods from the available eval-codes coming from the database within my class.

I thought of the following pseudocode so that the eval code is converted to a method:

class foo
{
    private $test=3;
    public function doloop()
    {   
        for($i=0;$i<5;$i++)
        {
            $string="echo 50 * \$this->test.'<br>';";
            $func="evalcode_001";
            if(!isset(${$func}))
            {
                ${$func}=create_function('',$string);
            }

            ${$func}();
        }
    }
}
$obj_foo = new foo();
$obj_foo->doloop();//must output '150<br>150<br>150<br> .....'

However when running it I get the error message "Using $this when not in object context in ...". So obviously I didn't really create methods within the class.

So my question is: How do I create a method for a class dynamically and assign code for the given method. Basically I want to be able to do:

$obj_foo->evalcode_001(); 

in the above example.

Help appreciated

PS I am using PHP5.4

Answer 1

If you can change $this->test inside string (or write extra preg_match) you can use:

<?php

class foo
{
    public $test=3;

    public $functions = array();
    public function doloop()
    {   
        for($i=0;$i<5;$i++)
        {
            $string="echo 50 * \$this->test.'<br>';";
            $func="evalcode_001";
            if(!isset($this->functions[$func]))
            {
                $string = str_replace('$this','$object', $string );
                $this->functions[$func]= create_function('$object',$string);                
            }

            $this->functions[$func]($this);
        }
    }

    public function __call($name, $arguments) {
      if (isset($this->functions[$name])) {
          return $this->functions[$name]($this);          
      }
    }

    public function otherMethod() {
        echo "test";

    }     

}


$obj_foo = new foo();
$obj_foo->doloop();//must output '150<br>150<br>150<br> .....
$obj_foo->evalcode_001();
$obj_foo->otherMethod();

However as other said I wouldn't like to use anything like that in my real script