Question

i have a function inside a Class that is inside another, this way i can organize all my ‘module’s engines’ in different folders and call they functions.

For example, i have a module called ‘mdnewsletter‘, that module has other classes inside like: ‘setting’, ‘newsletter’, etc.

Normally, if i wan’t to get the newsletter vars with id ‘5’ i do this:

$res = $mdnewsletter->newsletter->get(5);
if($res===false) { /* error handler here */ }

/* otherwise, the code here */

But now i have a module called ‘mdapi’. The propose of this module is to securely load another module’s engine and execute commands only for modules.

My question is on this code snippet:

            $response = @eval($eval);
            if($response===false && ( $error = error_get_last() )){
                $this->error[] = "mdapi->exec() | A função fornecida não é uma função válida";
                $can_exec = false;
                $eval = '';
                $response = false;
            };

As i get the execution string has ‘mdnewsletter->newsletter->get’ and arguments in other var, i can’t use method_exists(). I really prefer to read the parse error code.

If an parse error occurs, the php code will hang and i can’t inform the other side that the code is bad or an error occurred.

How can i fix this?

EDIT:
Based on Oktopus answer, i’ve wrote a code that dynamically checks all the objects behind the function and then it test the function with last object, something like this:

            // Avaliar se a primeira parte é uma class e os restantes funcoes
            $tmp = explode ('->', $tmp);

            // Verificar se são objectos até à função (ultima string)
            $obj = $$tmp[0];
            for($i=0;$i<count($tmp)-1;$i++){
                if($i!=0){
                    $obj = $obj->$tmp[$i];
                }
                if(!is_object($obj)){
                    $this->error[] = "mdapi->exec() | A variavel '".$tmp[$i]."' não é um objecto!";
                    $can_exec = false;
                    $eval = '';
                    $response = false;
                }
            }

            // Verificar se a ultima variavel é uma função no ultimo objecto
            if(!is_callable(array($obj, $tmp[count($tmp) - 1]))){
                $this->error[] = "mdapi->exec() | A função pedida não foi encontrada no ultimo objecto!";
                $can_exec = false;
                $eval = '';
                $response = false;
            }

Answer 1

I won’t go in the “it may be insecure thing”, but here is how you could do it :

//Exemple string : 
$parts = explode ('->', "object->property->testCall");
//How to test if it's callable
if (is_object($$parts[0]->$parts[1])){
    echo "it's an object";
    if (is_callable(array($$parts[0]->$parts[1], $parts[2]))){
        echo "it's callable";
    }
}