Try Catch

[The Little Guy]

I added this to one of my methods:

try{
$this->hooksFired++;
call_user_func(array($this->$hook, $method));
}catch($e){ // Line 32

}

 

and I am getting this error:

 

Parse error: syntax error, unexpected T_VARIABLE, expecting T_STRING or T_NAMESPACE or T_NS_SEPARATOR in C:\Users\Ryan\Documents\NetBeansProjects\cleepcms\cleepcms\classes\Hook.php on line 32

 

I am not sure what is wrong, anyone know why I am getting that error?

[The Little Guy]

I got it, but it didn't seem to do what I wanted.

 

I am looking to skip calling call_user_func(array($this->$hook, $method)); if the calling function has an error in it, such as a missing simi-colon.

 

Any way I can do that?

[requinix]

That would trigger a parse error as soon as the file is loaded. I don't remember for sure but you might be able to trap the error with set_error_handler() and interrupt the script however you see fit (such as by throwing an exception). Maybe. If not then you'd have to run the file through php -l and look for complaints.

 

Or you could just let the error happen. It's a parse error after all. It should never, ever happen in real code.

[peipst9lker]

You need to provide an identifier in catch-blocks e.g

 

try {
$this->hooksFired++;
call_user_func(array($this->$hook, $method));
} catch (Exception $e) {
// error handling code
}

[silkfire]

call_user_func requires a callback as its argument. Why on earth do you put an array there?

[xyph]

call_user_func requires a callback as its argument. Why on earth do you put an array there?

 

In the case of an object, you use an array. The first value being a reference to the object, the second value being the method name

 

From the manual entry, Example 4

<?php

class myclass {
    static function say_hello()
    {
        echo "Hello!\n";
    }
}

$classname = "myclass";

call_user_func(array($classname, 'say_hello'));
call_user_func($classname .'::say_hello'); // As of 5.2.3

$myobject = new myclass();

call_user_func(array($myobject, 'say_hello'));

?>

[The Little Guy]

That would trigger a parse error as soon as the file is loaded. I don't remember for sure but you might be able to trap the error with set_error_handler() and interrupt the script however you see fit (such as by throwing an exception). Maybe. If not then you'd have to run the file through php -l and look for complaints.

 

Or you could just let the error happen. It's a parse error after all. It should never, ever happen in real code.

 

set_error_handler doesn't catch these errors:

E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING

 

So the only thing I could also think of was doing exec("php -l filename.php");.

 

But I feel it would be better not to if possible.

[xyph]

Parse errors shouldn't happen outside of development.

[The Little Guy]

Parse errors shouldn't happen outside of development.

 

I am making a CMS, and you can create plugins for it right within the CMS, and if while developing a plugin you have a syntax error it can bring the entire system to a halt making it so you can no longer edit the file unless you edit it externally.

 

Or maybe you download a plugin that was poorly coded, that could bring the server to a halt too.

[xyph]

In this case, run the code through eval. A parse error will result in FALSE.

 

On another note, there are so many things wrong with allowing developers to code PHP-based-plugins directly in the CMS.

[The Little Guy]

On another note, there are so many things wrong with allowing developers to code PHP-based-plugins directly in the CMS.

 

Such as what?

[requinix]

set_error_handler doesn't catch these errors:

E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING

I vaguely remember a way that you could catch one/some of those, in some special circumstance probably under your control. Of course I don't remember how.

[xyph]

On another note, there are so many things wrong with allowing developers to code PHP-based-plugins directly in the CMS.

 

Such as what?

 

Lack of development environment, for one.

 

Are you coding some sort of IDE in your CMS?

[The Little Guy]

I am using http://codemirror.net for my "IDE", and if  you need more, that what my "IDE" offers, you do have the ability to code in your own editor if you wish.

[xyph]

Syntax highlighting should be helpful. Regardless, you've got your mind made up, so best of luck. Again, eval will help you weed out fatal errors.

 

<?php

ob_start();
$result = eval('blah');
$response = ob_get_clean();
if( $result === FALSE ) {
if( stristr($response, 'parse error') !== FALSE )
	echo 'We found a parse error';
}

?>

[The Little Guy]

but wont eval actually run the code?

[xyph]

It sure will...

 

Perhaps you want to set up some sort of client with xdebug and DBGp? Or write your own parser? Or simply have your developers code plug-ins in a development environment?

[ignace]

You can use either register_shutdown_function or ob_start to register a function that will handle the resulting output. With error_get_last you can retrieve the last occured error (fatal error). I've used this on a few occasions with success. I always use register_shutdown_function in combination with error_get_last.

[The Little Guy]

doesn't register_shutdown_function exit the current script once the function is done though?

 

If that is the case I can't have that. I added a lint test which seems to work I will then take the errors from that and save them to a custom error logging system.

[ignace]

You can do something like:

 

register_shutdown_function(function() {
  if ($error = error_get_last()) {
    header('Location: error.php?ser=' . urlencode(serialize($error)));
  }
});