Re: array walk and class member functions

[Tom <tom@xxxxxxxxxxxxxxxxxxxxx>]

Thanks very much for the help - both methods work fine. I'd had a look 
at the array_walk manual, but didn't realise that the second param would 
accept an array - that's really cool!

I don't like the function_exists method much, as I frequently overload 
class members. Not needed now as I have the worker defined as a private 
function and can access it from the public one as
array_walk($anArray,array($this,'aFunction');

Thanks

Tom
Jochem Maas wrote:

> Tom wrote:
>
> > Hi
> >
> > I'm batting my head against a wall on this one...
> > I have a class that has a constructor which sets some initial 
> > conditions, and then a public function that does some work. I want to 
> > be able to call this function from an external array_walk call, but 
> > when I try and reference it as $myClass->myFunction in the array_walk 
> > call, I get an error back saying that this is an invalid function.
> >
> > eg)
> > <?php
> >    include "../includes/aClass.class";
> >
> >    $myArray = array("item1"=>"firstItem", "item2"=>"secondItem");
> >    $myClass = new aClass;
> >
> >    array_walk($myArray,'$myClass->aMemberFunction');
>
>
> try changing this line to:
>
> array_walk($myArray, array($myClass,'aMemberFunction'));
>
> or if you prefer to take the route of your second attempt read on...
>
> > ?>
> >
> > As a workaround, I redifined the class so that there was a public 
> > function which made the array_walk call with the worker function 
> > defined internally as follows, but this throws another issue in that 
> > if I create multiple instances of the class then I get an error to 
> > say that the internal function is already defined ...
>
>
> which is correct, you are trying to create this function multiple times.
>
> > > *Fatal error*: Cannot redeclare aFunction() (previously declared in 
> > > /usr/local/apache2/htdocs/includes/functions.php:23) in 
> > > */usr/local/apache2/htdocs/includes/functions.php* on line *23*
> >
> >
> >
> > class aClass
> > {
> >     some other stuff, constructor etc
> >    public function aPublicFunction($anArray)
> >    {
> >       global $aRetrunString;
> >            function aFunction($value, $key)
> >       {
> >            global $aReturnString;
> >            $aReturnString = $aReturnString.$value;               }
> >
> >       array_walk($anArray,'aFunction');
> >       return $aReturnString;
> >    }
>
>
> wrap the function def. like so:
>
>     if (!function_exists('aFunction')) {
>     function aFunction($value, $key)
>     {
>         global $aReturnString;   
>         $aReturnString = $aReturnString.$value;
>     }
>     }
>
> OR define the function outside of the class e.g.
>
> function aFunction($value, $key)
> {
>     global $aReturnString;   
>     $aReturnString = $aReturnString.$value;
> }
>
> BTW: using a global in the way you do in this function is a bad idea.
> array_walk() is defined as follows:
>
> bool array_walk ( array &array, callback funcname [, mixed userdata])
>
> check out the manual for info on the last arg:
> http://nl2.php.net/array_walk
>
> > }
> >
> >   Can anyone help me to get either solution to a working state?
> >
> > By the way...
> > apache 2.0.49
> > php-5.0.2
> >
> > Thanks very much
> >
> > Tom

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