[Resolved] Advice on dyanmic function and passing arguments

vaaaska

It works, but I'm not sure about this method (I'm not putting this into the critique corner because it's not finished stuff nor do I feel it's interesting enough).

Anyways, I'm trying to call up functions from a functions repository so that I don't have to create really large files of just functions. Trying to break things down basically into smaller pieces.

So, I call up a function like this where the func() function sets up the actual function (you can see that the arguments are all mashed together):

$s = func(hello,"this,that,$and,the,$other");

Then, in my function I explode out the arguments for usage:

function hello($args) {

$arg = explode(',',$args);
$s = "Yeah, it works - $arg[4].";

return $s;
}

Reading about some of the other functions tools I didn't find a more convenient (probably not the correct word I'm looking for) way to make this happen. So, I guess I'm leading up a better practice kind of question...

???

Edit: "Sort of" works. If I have more than one argument one of them can not be an array (as far as I can tell). I could call up the array globally but I should probably find a way to deal with this. Hmmm...

Weedpacket

You could probably do something with [man]func_get_args[/man], and co.; [man]call_user_func_array[/man] is there as well to enable storing variable lists of arguments as arrays.

function hello() {

$arg = func_get_args();
$s = "Yeah, it works - $arg[4].";

return $s;
}

hello('this', 'that', $and, 'the', $other);

vaaaska

I'm beginning to wonder if this is a smart idea or not...

I think I can narrow down the problem I have with both methods above...since I'm trying to run a check on whether file exists (and whether it needs to be included) I'm having a hard time getting the arguments to pass. Both, have the same problem (which is probably just me)...

If I have

$arguments = 'this','that','other'; // created by a loop...
$func($arguments);

Its says that arguments two and three are missing. ?

Now, if I simply edit it to read:

$func('this','that','other');

It works. Of course, it doesn't really work though...

Even with callback it recognized $arguments as only one argument so I can't call them in separately...and hence having the same problem both ways around.

I'm still not really addressing the problem with arrays, but I might be able to live without that...

Perhaps a more simple question...should I really even go this route? Maybe this really isn't more simple...

vaaaska

Sometimes thinking backwards is thinking forwards...I think I have it now. I'll post this messy solution if it's true (for future reference).

Thanks...v

Weedpacket

Well, since

$arguments = 'this','that','other'; // created by a loop...

is bad syntax, I'm not clear on what you're passing - I'm guessing you mean

$arguments = array('this','that','other'); // created by a loop...

? In that case $func() will only get one argument - containing the entire array.

$arguments = array('this','that','other');
call_user_func_array($func, $arguments);

Is equivalent to

$func('this','that','other');

With that you'd really need to use [man]func_get_args[/man], since it could have an arbitary number of arguments passed to it.

Of course, maybe I've got the wrong end of this particular stick entirely.

vaaaska

No, you were right. I had gone through the callback stuff and it was being (obviously) particular with the arguments. I just had to sit here and work through it in my slow way...

This is all messy (and will get some souping up)...but is a simple way to call up functions that exist on their own independent from a huge file with all your functions...

Call up a function in a wrapper function...

$output = func("hello","these","are","arguments",$array);

Then grab the info and func() figures out all the details and uses call_user_func_array() and gets busy:

function func($func,$args) {

// get the number of arguments
$numargs = func_num_args();
// get an array of the arguments (like explode sort of)
$arg_list = func_get_args();

// check to see if your function exists
// the first arg will always be the name of the function
if (function_exists($arg_list[0])) {

if ($numargs >= 1) {

		// we don't want the first argument in our loop (see above)
		for($i=1; $i < count($arg_list); $i++) {

		// need to check if it's an array - so we can pass arrays
		if(!is_array($arg_list[$i])) {
		$parameter[] = "$arg_list[$i]";
		} else {
		$parameter[] = $arg_list[$i];
		}
	}
}
// happy happy, joy joy
return call_user_func_array("$arg_list[0]",$parameter);

} else {

// if the function doesn't exist check to see if it's out there
if (file_exists($_SERVER['DOCUMENT_ROOT']."/functions/$arg_list[0].function.php")) {
	// go get it if the file does exist
	@include_once $_SERVER['DOCUMENT_ROOT']."/functions/$arg_list[0].function.php";

	// same thing again
	if ($numargs >= 1) {
	$arg_list = func_get_args();
		for($i=1; $i < count($arg_list); $i++) {
		if(!is_array($arg_list[$i])) {
		$parameter[] = "$arg_list[$i]";
		} else {
		$parameter[] = $arg_list[$i];
		}
	}
}
return call_user_func_array("$arg_list[0]",$parameter);

} else {

	// woops, can't find anything...
	echo "Could not load $arg_list[0].function.php.";
}

}
}

Now, perhaps this could go to Code Critique, but if there are any obvious things I might know I'm open.

Merci...

Weedpacket

Nice to hear you've got it working. At a very brief glance I can just see two things that could be improved upon:

 if(!is_array($arg_list[$i])) {
            $parameter[] = "$arg_list[$i]";
            } else {
            $parameter[] = $arg_list[$i];
            }

Unless you really do want to cast non-array arguments to strings (and what about objects or resources?), this test is unneeded, and could be replaced by

$parameter[] = $arg_list[$i];

The other thing is that you can save yourself a bit of effort (including the loop alluded to above) by preprocessing your arguments list:

    $arg_list = func_get_args(); 
$function_name = array_shift($arg_list);

Now you can replace $arg_list[0] with $function_name, and $arg_list contains only the arguments to that function.

Actually, you don't even need $function_name at all: when you declared func() it was with two parameters, so $numargs will always be at least two, with $func containing the name of the function; therefore

array_shift($arg_list);

alone will tidy up that array (which, as it happens, will be guaranteed to have at least one element) and $func will then replace $arg_list[0].

So, with that in mind:

function func($func,$args) {

// get an array of the arguments (like explode sort of)
$arg_list = func_get_args();
array_shift($arg_list);

// check to see if your function exists
// the first arg will always be the name of the function
if (function_exists($func)) {

return call_user_func_array($func,$arg_list);

} else {

// if the function doesn't exist check to see if it's out there
if (file_exists($_SERVER['DOCUMENT_ROOT']."/functions/$func.function.php")) {
	// go get it if the file does exist
	@include_once $_SERVER['DOCUMENT_ROOT']."/functions/$func.function.php";

return call_user_func_array($func,$arg_list);

} else {

	// woops, can't find anything...
	echo "Could not load $func.function.php.";
}

}
}

vaaaska

I realize now the title of this thread was not really correct - in fact, it's way off. ???

I can see the steam rising off of this one. 😉

It's cool when you see a pro reduce the inner workings - I believe I learn alot from these instances but I won't pat myself on the back.

Thanks...v