Accessors

[Philip Thompson <philthathril@xxxxxxxxx>]

Hi all.

Maybe I'm wanting more Java-like functionality out of PHP, but I don't  
really like getting and setting members directly (even for public  
members) - I'd rather use accessors. This way you can control what is  
getting set and what is returning. However, I also don't really want  
to create a million get/set accessor methods - this is no fun and  
takes up a lot of space. After reading around a little bit, it got me  
thinking about overloading in PHP (which I'm sure we all know is  
completely different than any other language... but that's another  
day). I didn't want to use the standard __get and __set methods  
because that still leaves me with the same notation for getting/ 
setting members. So, instead, I used a close relative of __get and  
__set. Meet brother __call. Could it really be this trivial to get the  
notation I'm wanting? Yes. Yes it is. Ok, enough talking... onto the  
code.

<?php
class Person
{
    public $age;
    private $first, $middle, $last;

    // Gotta have our construct
    public function __construct () {}

    // Here's the fun
    public function __call ($member, $args)
    {
        // Since I know members I want, force the user to only
        // access the ones I've created
        if (property_exists ('Person', $member)) {
            // If args is empty, I must be returning the value
            if (empty ($args)) {
                list ($value) = $this->$member;
                return $value;
            }

            // Oh, args is not empty! Set the value
            $this->$member = $args;
        }
        else {
            // Blow up!
            die ("Fatal Error: Call to undefined member: $member.  
Exiting...");
        }
    }
}

$person = new Person();

// Set the (private) first and last names
$person->first('Billy');
$person->last('Bob');

// Get the (private) first and last names
echo $person->first() . " " . $person->last()."<br/>";

// Set the (public) age
$person->age(103);

// Get the (public) age
echo "Age: ".$person->age()."<br/>";

// Explosions
$person->first = 'Buford';
$person->pizza('Is yummy');
?>

Now if you're reading this and thinking "Duh!" then good for you.  
However, I know there's at least 1 soul on this list who may benefit  
from this. But don't stop at the example above. If you want to add  
validation to the members you're getting/setting, build that into your  
code. If you want each member to be a specific type, include that as  
well (I'll leave the implementation up to you). ;-)

So let's recap.

•  This functionality allows me to not have to write 2 accessors for  
every member
•  This allows me to use methods instead of directly getting/setting  
members (even though I can still access public members directly... if  
I want)
•  Keeps code consistent and less confusing - I know how to get and  
set every member

What are your thoughts? Does this seem like a reasonable  
implementation? Useful? Pointless? Hit me up - I can handle  
*constructive* criticism. But for now, it's late and past my bedtime.

Cheers,
~Philip

"innerHTML is a string. The DOM is not a string, it's a hierarchal  
object structure. Shoving a string into an object is impure and  
similar to wrapping a spaghetti noodle around an orange and calling it  
lunch."
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