array_walk - userdata as array by ref

[Steve]

here's a quirk i can't seem to handle, just hack. since call-time
by-reference is depreciated and i don't want to enable it in the php.ini,
i'm kind of stuck when i want to pass userdata as an array byref that is
initially = array().

// the array being walked
$numbers = array(1, 56, 999, 1000, 28, 65);

// the work-around

// the callback
function validateInput(&$value, $key, &$errors)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errors[1][$key] = 'Element ' . $key. ' must be a whole number between 0
and ' . $maxValue . '.';
}
// the hack
$error = array();
$errors = array('', &$error);
array_walk($numbers, 'validateInput', $errors);
$errors = $errors[1];
print_r($errors);

// what i'd like to do

// the callback
function validateInput(&$value, $key, &$errors)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errors[$key] = 'Element ' . $key. ' must be a whole number between 0 and
' . $maxValue . '.';
}
$errors = array();
array_walk($numbers, 'validateInput', $errors);
print_r($errors);
it seems as though php doesn't allocate memory for $errors when it is
defined as an empty array since it has no data (!isset), and therefore
there's a pointer to nothing (figuratively). i assume since $errors =
array('', &$error) allocates memory for the structure, the callback then has
something to work on. the '' being what actually triggers allocation (makes
room for \0 i guess). that was my reasoning when i came up with the hack,
but i'd like to know for sure.

does that sound about right? suggestions on getting the results i looking
for?

tia,

me

[Hendri Kurniawan]

Steve wrote:

here's a quirk i can't seem to handle, just hack. since call-time
by-reference is depreciated and i don't want to enable it in the php.ini,
i'm kind of stuck when i want to pass userdata as an array byref that is
initially = array().

// the array being walked
$numbers = array(1, 56, 999, 1000, 28, 65);

// the work-around

// the callback
function validateInput(&$value, $key, &$errors)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errors[1][$key] = 'Element ' . $key. ' must be a whole number between 0
and ' . $maxValue . '.';
}
// the hack
$error = array();
$errors = array('', &$error);
array_walk($numbers, 'validateInput', $errors);
$errors = $errors[1];
print_r($errors);

// what i'd like to do

// the callback
function validateInput(&$value, $key, &$errors)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errors[$key] = 'Element ' . $key. ' must be a whole number between 0 and
' . $maxValue . '.';
}
$errors = array();
array_walk($numbers, 'validateInput', $errors);
print_r($errors);
it seems as though php doesn't allocate memory for $errors when it is
defined as an empty array since it has no data (!isset), and therefore
there's a pointer to nothing (figuratively). i assume since $errors =
array('', &$error) allocates memory for the structure, the callback then has
something to work on. the '' being what actually triggers allocation (makes
room for \0 i guess). that was my reasoning when i came up with the hack,
but i'd like to know for sure.

does that sound about right? suggestions on getting the results i looking
for?

tia,

me

Both of the code you posted did not work on my box (php5.2) unmodified.

My initial thought will be using foreach on the array $numbers, but you
might have your own reason not to use it.
Hendri Kurniawan

[Steve]

| Both of the code you posted did not work on my box (php5.2) unmodified.
|
| My initial thought will be using foreach on the array $numbers, but you
| might have your own reason not to use it.

i usually do. however, i'm prototyping something. here's what gives me the
results...in case my free-handed post is why it doesn't work on your box.
thanks for looking at it. sorry for the text-wrapping here...if you just
backspace the wrap, it should be very easy to read/follow.

<?
$inputs['Personnel'] = array(
'bodyTech' =0 ,
'bodyTechAppr' =0 ,
'paintTech' =0 ,
'paintTechAppr' =0 ,
'paintPreps' =0 ,
'mechanicTechs' =0 ,
'estimators' =0 ,
'otherEmployees' =0
);
$inputs['Facility'] = array(
'bodyShopLocation' ='' ,
'franchises' ='' ,
'totalSqFeet' =0 ,
'productionSqFeet' =0 ,
'totalWorkStations' =0 ,
'totalPaintBooths' =0 ,
'totalDetailStalls' =0
);
function retrieveInput(&$value, $key, $source)
{
$default = 0;
if ($key == 'bodyShopLocation'){ $default = ''; }
if ($key == 'franchises'){ $default = ''; }
$value = isset($source[$key]) ? $source[$key] : $default;
}
function validateInput(&$value, $key, &$errors)
{
$inputName = '';
$maxValue = 999;
switch ($key)
{
case 'bodyShopLocation' : if (in_array($value, array('', 'ON SITE',
'OFF SITE'))){ return; }
$errors[$key] = 'BODY SHOP LOCATION must be
either on-site or off-site.';
return;
break;
case 'franchises' : if (in_array($value, array('', 'SINGLE',
'MULTIPLE'))){ return; }
$errors[$key] = 'FRANCHISE TYPE must be
either single or multiple.';
return;
break;
case 'bodyTech' : $inputName = 'BODY TECHNICIANS';
break;
case 'bodyTechAppr' : $inputName = 'BODY TECHNICIAN APPRENTICES';
break;
case 'paintTech' : $inputName = 'PAINT TECHNICIANS';
break;
case 'paintTechAppr' : $inputName = 'PAINT TECHNICIAN APPRENTICES';
break;
case 'paintPreps' : $inputName = 'PAINT PREPS';
break;
case 'mechanicTechs' : $inputName = 'MECHANICAL TECHNICIANS';
break;
case 'estimators' : $inputName = 'ESTIMATORS';
break;
case 'otherEmployees' : $inputName = 'OTHER EMPLOYEES';
break;
case 'totalSqFeet' : $inputName = 'TOTAL SQUARE FEET';
$maxValue = 9999999; break;
case 'productionSqFeet' : $inputName = 'PRODUCTION AREA SQUARE FEET';
$maxValue = 9999999; break;
case 'totalWorkStations' : $inputName = 'TOTAL WORK STATIONS';
break;
case 'totalPaintBooths' : $inputName = 'TOTAL PAINT BOOTHS';
break;
case 'totalDetailStalls' : $inputName = 'TOTAL DETAIL STALLS';
break;
default : return; break;
}
if ($value <= $maxValue) return;
$errors[1][$key] = $inputName . ' must be a whole number between 0 and ' .
$maxValue . '.';
}
array_walk($inputs['Personnel'], 'retrieveInput', $_REQUEST);
array_walk($inputs['Facility'], 'retrieveInput', $_REQUEST);
$error = array();
$errors = array('', &$error);
array_walk($inputs['Personnel'], 'validateInput', $errors);
array_walk($inputs['Facility'], 'validateInput', $errors);
$errors = count($errors) 1 ? $errors[1] : array();
echo '<pre>' . print_r($inputs, true) . '</pre>';
echo '<pre>' . print_r($errors, true) . '</pre>';
?>

[Hendri Kurniawan]

Steve wrote:

| Both of the code you posted did not work on my box (php5.2) unmodified.
|
| My initial thought will be using foreach on the array $numbers, but you
| might have your own reason not to use it.

i usually do. however, i'm prototyping something. here's what gives me the
results...in case my free-handed post is why it doesn't work on your box.
thanks for looking at it. sorry for the text-wrapping here...if you just
backspace the wrap, it should be very easy to read/follow.

<SNIPPED CODE>

Umm.. again sorry if this is not the answer you are looking for.
This is what i came up with (see bottom of page)

What it basically does is that it replaces the array_walk to normal
function. Inside the function, instead of returning after correctly
validating the input, I've put "continue".

At the end i returned the errors array.
Hendri Kurniawan

<?
$inputs['Personnel'] = array(
'bodyTech' =0 ,
'bodyTechAppr' =0 ,
'paintTech' =0 ,
'paintTechAppr' =0 ,
'paintPreps' =0 ,
'mechanicTechs' =0 ,
'estimators' =0 ,
'otherEmployees' =0
);
$inputs['Facility'] = array(
'bodyShopLocation' ='' ,
'franchises' ='' ,
'totalSqFeet' =0 ,
'productionSqFeet' =0 ,
'totalWorkStations' =0 ,
'totalPaintBooths' =0 ,
'totalDetailStalls' =0
);
function retrieveInput(&$value, $key, $source)
{
$default = 0;
if ($key == 'bodyShopLocation'){ $default = ''; }
if ($key == 'franchises'){ $default = ''; }
$value = isset($source[$key]) ? $source[$key] : $default;
}
function validateInput($value)
{
$inputName = '';
$maxValue = 999;
$errors = array();
foreach($value as $key=>$value) {
switch ($key)
{
case 'bodyShopLocation' :
if (in_array($value, array('', 'ON SITE', 'OFF SITE'))){ continue; }
$errors[$key] = 'BODY SHOP LOCATION must be either on-site or
off-site.';
continue;
break;
case 'franchises' :
if (in_array($value, array('', 'SINGLE', 'MULTIPLE'))){ continue; }
$errors[$key] = 'FRANCHISE TYPE must be either single or multiple.';
continue;
break;
case 'bodyTech' : $inputName = 'BODY TECHNICIANS';
break;
case 'bodyTechAppr' : $inputName = 'BODY TECHNICIAN APPRENTICES';
break;
case 'paintTech' : $inputName = 'PAINT TECHNICIANS';
break;
case 'paintTechAppr' : $inputName = 'PAINT TECHNICIAN APPRENTICES';
break;
case 'paintPreps' : $inputName = 'PAINT PREPS';
break;
case 'mechanicTechs' : $inputName = 'MECHANICAL TECHNICIANS';
break;
case 'estimators' : $inputName = 'ESTIMATORS';
break;
case 'otherEmployees' : $inputName = 'OTHER EMPLOYEES';
break;
case 'totalSqFeet' : $inputName = 'TOTAL SQUARE FEET';
$maxValue = 9999999; break;
case 'productionSqFeet' : $inputName = 'PRODUCTION AREA SQUARE FEET';
$maxValue = 9999999; break;
case 'totalWorkStations' : $inputName = 'TOTAL WORK STATIONS';
break;
case 'totalPaintBooths' : $inputName = 'TOTAL PAINT BOOTHS';
break;
case 'totalDetailStalls' : $inputName = 'TOTAL DETAIL STALLS';
break;
default : continue; break;
}
if ($value <= $maxValue) continue;
$errors[$key] = $inputName . ' must be a whole number between 0 and ' .
$maxValue . '.';
}

return $errors;
}

array_walk($inputs['Personnel'], 'retrieveInput', $_REQUEST);
array_walk($inputs['Facility'], 'retrieveInput', $_REQUEST);
$errors = array();
$errors = array_merge($errors,validateInput($inputs['Personnel']));
$errors = array_merge($errors,validateInput($inputs['Facility']));
echo '<pre>' . print_r($inputs, true) . '</pre>';
echo '<pre>' . print_r($errors, true) . '</pre>';
?>

[Steve]

"Hendri Kurniawan" <as****@email.comwrote in message
news:13*************@corp.supernews.com...

thanks hendri. btw, i didn't know you could do:

foreach($value as $key=>$value)

and expect to have the first $value preserved. i suppose though, thinking
about it, php gets a single reference to the $value array and then works off
the stack at that address. the second $value should be a new copy of the
element at $key - the next loop still working from the old stack and not the
new value of $value.

it's not so much that i want an alternative, it's that i want to understand
exactly why the hack works yet the straight-forward approach does not - even
though the docs say it should. i'm just using array_walk to benchmark
data-retrieval in a custom db class...rather than using a foreach on the
records returned, i'd be trying to walk the records - goal being to
standardize access methods, i.e. $records[0]['FOO'] as the structure...a row
and field as keys. the foreach is pretty fast over 200K rows...just wanna
see how much faster the native iteration is over the native enumeration. :)
i'm just wierd like that.

anyway, the code i posted here was me just playing with array_walk in a
practical scenario. just trying to find out about what all i could do with
the userdata param. that's when i ran into this bit of undefined behavior.
and, isn't it wonderful that it is undefined yet a single character's
correction would fix the problem - that character being '&' as a call-time
by-reference.

thanks for the help.

[Hendri Kurniawan]

Steve wrote:

| Both of the code you posted did not work on my box (php5.2) unmodified.
|
| My initial thought will be using foreach on the array $numbers, but you
| might have your own reason not to use it.

i usually do. however, i'm prototyping something. here's what gives me the
results...in case my free-handed post is why it doesn't work on your box.
thanks for looking at it. sorry for the text-wrapping here...if you just
backspace the wrap, it should be very easy to read/follow.

Also forgot to mention that posted code also doesn't work.
(You might have found a bug?? :D )

Hendri Kurniawan

[Hendri Kurniawan]

Steve wrote:

"Hendri Kurniawan" <as****@email.comwrote in message
news:13*************@corp.supernews.com...

thanks hendri. btw, i didn't know you could do:

foreach($value as $key=>$value)

and expect to have the first $value preserved. i suppose though, thinking
about it, php gets a single reference to the $value array and then works off
the stack at that address. the second $value should be a new copy of the
element at $key - the next loop still working from the old stack and not the
new value of $value.

it's not so much that i want an alternative, it's that i want to understand
exactly why the hack works yet the straight-forward approach does not - even
though the docs say it should. i'm just using array_walk to benchmark
data-retrieval in a custom db class...rather than using a foreach on the
records returned, i'd be trying to walk the records - goal being to
standardize access methods, i.e. $records[0]['FOO'] as the structure...a row
and field as keys. the foreach is pretty fast over 200K rows...just wanna
see how much faster the native iteration is over the native enumeration. :)
i'm just wierd like that.

anyway, the code i posted here was me just playing with array_walk in a
practical scenario. just trying to find out about what all i could do with
the userdata param. that's when i ran into this bit of undefined behavior.
and, isn't it wonderful that it is undefined yet a single character's
correction would fix the problem - that character being '&' as a call-time
by-reference.

thanks for the help.

Yeah, glad to help.. It also challenges my mind not to be complacent.

Hendri

[Steve]

| Also forgot to mention that posted code also doesn't work.
| (You might have found a bug?? :D )

well, if it is consistent then it's a 'feature', right? lol.

btw, i ran it on php 5.1.6.

[gosha bine]

On 20.04.2007 05:57 Steve wrote:

here's a quirk i can't seem to handle, just hack. since call-time
by-reference is depreciated and i don't want to enable it in the php.ini,
i'm kind of stuck when i want to pass userdata as an array byref that is
initially = array().

// the array being walked
$numbers = array(1, 56, 999, 1000, 28, 65);

// the work-around

// the callback
function validateInput(&$value, $key, &$errors)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errors[1][$key] = 'Element ' . $key. ' must be a whole number between 0
and ' . $maxValue . '.';
}
// the hack
$error = array();
$errors = array('', &$error);
array_walk($numbers, 'validateInput', $errors);
$errors = $errors[1];
print_r($errors);

// what i'd like to do

// the callback
function validateInput(&$value, $key, &$errors)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errors[$key] = 'Element ' . $key. ' must be a whole number between 0 and
' . $maxValue . '.';
}
$errors = array();
array_walk($numbers, 'validateInput', $errors);
print_r($errors);
it seems as though php doesn't allocate memory for $errors when it is
defined as an empty array since it has no data (!isset), and therefore
there's a pointer to nothing (figuratively). i assume since $errors =
array('', &$error) allocates memory for the structure, the callback then has
something to work on. the '' being what actually triggers allocation (makes
room for \0 i guess). that was my reasoning when i came up with the hack,
but i'd like to know for sure.

does that sound about right? suggestions on getting the results i looking
for?

tia,

me

Hi

how about

function validateInput(&$value, $key, $errs)
{
$maxValue = 999;
if ($value <= $maxValue) return;
$errs[0][$key] = "message...";
}

array_walk($numbers, 'validateInput', array(&$errors));
print_r($errors);


--
gosha bine

extended php parser ~ http://code.google.com/p/pihipi
blok ~ http://www.tagarga.com/blok

[Steve]

| function validateInput(&$value, $key, $errs)
| {
| $maxValue = 999;
| if ($value <= $maxValue) return;
| $errs[0][$key] = "message...";
| }
|
| array_walk($numbers, 'validateInput', array(&$errors));
| print_r($errors);

beautiful...i check it. i wonder why it has to be that way instead of just
passing $errors in?

[Steve]

| function validateInput(&$value, $key, $errs)
| {
| $maxValue = 999;
| if ($value <= $maxValue) return;
| $errs[0][$key] = "message...";
| }
|
| array_walk($numbers, 'validateInput', array(&$errors));
| print_r($errors);

doesn't work on my machine (php 5.1.6)

[gosha bine]

On 20.04.2007 15:20 Steve wrote:

| function validateInput(&$value, $key, $errs)
| {
| $maxValue = 999;
| if ($value <= $maxValue) return;
| $errs[0][$key] = "message...";
| }
|
| array_walk($numbers, 'validateInput', array(&$errors));
| print_r($errors);

doesn't work on my machine (php 5.1.6)

works for me in php4.3 and 5.2. Make sure you're doing everything right.
--
gosha bine

extended php parser ~ http://code.google.com/p/pihipi
blok ~ http://www.tagarga.com/blok

[Steve]

"gosha bine" <st********@gmail.comwrote in message
news:46**********************@read.cnntp.org...
| On 20.04.2007 15:20 Steve wrote:
| | function validateInput(&$value, $key, $errs)
| | {
| | $maxValue = 999;
| | if ($value <= $maxValue) return;
| | $errs[0][$key] = "message...";
| | }
| |
| | array_walk($numbers, 'validateInput', array(&$errors));
| | print_r($errors);
| >
| doesn't work on my machine (php 5.1.6)
| >
| >
|
| works for me in php4.3 and 5.2. Make sure you're doing everything right.

including cut/paste. :)

it must be either how php is compiled or the settings it's running. i'll
keep playing with your example and see if i can get it there. btw, i don't
expect that there would be a problem with any of this in versions less than
php 5.

cheers.