Question

GOAL: Declare/set variables in the scope of the function that called the running function.

DETAILS:
Hey Overflowans,

I’m looking to add one last little piece of sugar to a utility that I use in a lot of my php functions. It allows me to define a flexible contract on the input of my functions. Over a few iterations, I’ve gotten it pared down to a usage that looks like this:

function doSomething($param_arr){
    FPX::contract(array(
        'required' => array("length", "width", "height", "weight"),
        'optional' => array("circumference")
    ));
    $length = $parr['length'];
    $width = $parr['width'];
    $height = $parr['height'];
    $weight = $parr['weight'];
    $circumference = $parr['circumference'];
    ....
}

FPX::contract() automatically grabs the $param_arr and parses it to make sure that it’s compatible with the defined contract.

What I would like to do now is eliminate the need to declare each of the variables afterwards. Is there a way that I can, within the lowest function, declare variables in the scope of the function that called it? So FPX::contract() needs to be able to set variables that are in the scope of doSomething() so that I don’t have to declare each of these variables. (I don’t want to declare globals).

Ideally it would just look like:

function doSomething($param_arr){
        FPX::contract(array(
            'required' => array("length", "width", "height", "weight"),
            'optional' => array("circumference")
        ));
    ....
}

And then doSomething() would be able to access each of the variables listed in the contract as $length, $width, etc.

I’m aware of the function($var0, $var1, $var2=null) syntax, but it’s not very easy to use this syntax with a large number of optional variables.

Thanks,
Ken

Answer 1

Maybe you can do something with extract()?

That is, just have your contract() return an array or a reference to an array, then extract() it.