Passing code to Closure/Annoymous function dynamically - php

Question

I wanted to create closure with dynamic code. To do that I wrote below code :-
function generateFunction ($class, $method){
$code = "require_once 'Init.php';";
$code = '$model = new '.$class.'();';
$code .= '$model->'.$method.'();';
return function() use(&$code){
return eval($code);
};
}
I know eval is evil but unable to find any alternative yet.
To get the function in variable I used below code :-
$myNewFunction = generateFunction ('svn', 'update');
Now I want to run this function by passing it as argument to my PHP file. But this function has same body on the output while I expected it to be like below.
function(){return eval(require_once 'Init.php';$model = new svn(); $model->update())}
Basically this need arise when I decided to integrate the Jobby.

Answer 1

Basically this need arise when I decided to integrate the Jobby.
I assume you want to create callback functions dynamically. Then your code is complete overkill and also doesn't need eval at all. You can get the same results by passing this as callback:
$callback = array(new SVN, 'update');
That's essentially all your code does anyway. Though with the difference that SVN is instantiated here, not when the callback is triggered. For an eval-free version of your code, this'll do:
function generateFunction($class, $method) {
return function () use ($class, $method) {
require_once 'Init.php';
$model = new $class;
return $model->$method();
};
}

Answer 2

To complete your answers, here is a complete example with jobby :
$jobby = new \Jobby\Jobby();
$WebSitesSchedule = new WebSitesSchedule();
$WebSitesSchedule->load_all();
foreach ($WebSitesSchedule as $WebSiteSchedule)
{
$Url = $WebSiteSchedule->ScheduleAction.'?'.$WebSiteSchedule->ScheduleParameters;
$jobby->add( "CmsSchedule_".strval($WebSiteSchedule->ScheduleID), array(
'command' => generateFunction($Url),
'schedule' => $WebSiteSchedule->ScheduleCron,
'output' => '/PATH/log/CmsSchedule.log',
'enabled' => true,
'debug' => true,
'recipients' => 'toto#gmail.com'
));
}
function generateFunction($Url)
{
return function () use ($Url)
{
$Result = Proxy::curl_request($Url);
if($Result["status"]==="success")
{
print_r($Result);
return TRUE;
}
else
{
print_r($Result);
return FALSE;
}
};
}
$jobby->run();

Answer 3

In your case you don't need to use eval(). You have to use call_user_func (or call_user_func_array) in conjunction with class_exists and method_exists instead.
require_once 'Init.php';
function generateFunction ($class, $method) {
if (!class_exists($class)) return false;
$model = new $class();
return method_exists($model, $method)? array($model, $method) : false;
}
$myNewFunction = generateFunction ('svn', 'update');
if ($myNewFunction) call_user_func($myNewFunction);