[PHP] array walk and class member functions
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,'$myClass-aMemberFunction');
?
As a workaround, I redifined the class so that there was a public
function which made the array_walk call with the worker function defined
internally as follows, but this throws another issue in that if I create
multiple instances of the class then I get an error to say that the
internal function is already defined ...
*Fatal error*: Cannot redeclare aFunction() (previously declared in
/usr/local/apache2/htdocs/includes/functions.php:23) in
*/usr/local/apache2/htdocs/includes/functions.php* on line *23*
class aClass
{
some other stuff, constructor etc
public function aPublicFunction($anArray)
{
global $aRetrunString;
function aFunction($value, $key)
{
global $aReturnString;
$aReturnString = $aReturnString.$value;
}
array_walk($anArray,'aFunction');
return $aReturnString;
}
}
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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Re: [PHP] array walk and class member functions
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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Re: [PHP] array walk and class member functions
Jochem Maas wrote:
Tom wrote:
snip
Sorry Tom, I hit the send button too early!
I mean to add some context to the code below so you would (hopefully)
understand what I mean:
OR define the function outside of the class e.g.
function aFunction($value, $key)
{
global $aReturnString;
$aReturnString = $aReturnString.$value;
}
...was meant to be:
function aFunction($value, $key)
{
global $aReturnString;
$aReturnString = $aReturnString.$value;
}
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 $aReturnString;
}
// rest of the class definition goes here...
snip
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Re: [PHP] array walk and class member functions
Tom wrote:
Thanks very much for the help - both methods work fine. I'd had a look
at the array_walk manual, but didn't realise that the second param would
accept an array - that's really cool
indeed that page does not make it very clear,
it's the generic call_back syntax, which can be used practically
everywhere a callback function is expected, the array you pass can be in
the form of:
array($object, 'methodname')
or
array('classname', 'methodname')
the second version allows you to use static class methods.
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Re: [PHP] array walk and class member functions
indeed that page does not make it very clear,
it's the generic call_back syntax, which can be used practically
everywhere a callback function is expected, the array you pass can be in
the form of:
array($object, 'methodname')
or
array('classname', 'methodname')
the second version allows you to use static class methods.
I never knew about this syntax until I saw it on this newsgroup quite a
few months back. Perhaps an update to the manual is in order?
(Whistling and walking away...)
--
Teach a person to fish...
Ask smart questions: http://www.catb.org/~esr/faqs/smart-questions.html
PHP Manual: http://www.php.net/manual/en/index.php
php-general archives: http://marc.theaimsgroup.com/?l=php-generalw=2
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Re: [PHP] array walk and class member functions
Thanks very much for the help - both methods work fine. I'd had a look
at the array_walk manual, but didn't realise that the second param would
accept an array - that's really cool!
I don't like the function_exists method much, as I frequently overload
class members. Not needed now as I have the worker defined as a private
function and can access it from the public one as
array_walk($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
--
PHP General Mailing List (http://www.php.net/)
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Re: [PHP] array walk and class member functions
Jason Barnett wrote:
indeed that page does not make it very clear,
it's the generic call_back syntax, which can be used practically
everywhere a callback function is expected, the array you pass can be
in the form of:
array($object, 'methodname')
or
array('classname', 'methodname')
the second version allows you to use static class methods.
I never knew about this syntax until I saw it on this newsgroup quite a
few months back. Perhaps an update to the manual is in order?
(Whistling and walking away...)
perhaps not:
http://www.php.net/manual/en/language.pseudo-types.php#language.types.callback
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