copying a reference

[cmerot]

hi,
i use a function (not mine) that returns a reference :

$mask = getMask('theMask');

and what I want to do is :

$mask = getMask('theMask');

$myMask = a copy of the value pointed by $mask
display ( modify ( $myMask ) );
$myMask2 = a fresh copy of the value pointed by $mask
display ( modify2 ( $myMask2 ) ); 

At the moment i cant copy the value pointed by $mask, so $myMask is a reference of $mask, that's why when i modify $myMask, i modify $myMask2 too !
Am i clear ? In case i am, can you help ?
Thanks,
Corentin

[laserlight]

Why not use:

$mask = 'theMask';
$myMask = $mask;
display (modify ($myMask));
$myMask2 = $mask
display (modify2($myMask2));

?

[cmerot]

because copying $mask means $myMask point the value of $mask (i cant change that $mask is a reference).
So first i modify $myMask, but in fact i modify $mask, that's why when i copy $mask as $myMask2, i get the previously modified value of $mask - $myMask - so $myMask2 is modified twice !

For information, this is what am trying to do really :

$mask = "<select name='screenSize'>
  <option value='17'>17 pouces</option>     

  <option value='21'>21 pouces</option>
</select>";
function modify($myMask, $value)
{
  if $value = '17'
  then add 'selected=\'selected\'' to the 
  <option value='17'>17pouces</option>
  of $myMask, resulting in :
    <option selected='selected' value='17'>17pouces</option>
}

Because my code modify $mask but not only $myMask as i would like and because i have a second screen (21 pouces), the second screen mask result is :

$myModifiedMask2 = "<select name='screenSize'>
  <option selected='selected' value='17'>17 pouces</option>     // modified by the first screen
  <option selected='selected'  value='21'>21 pouces</option>
</select>";

[laserlight]

um, 2 things:
1. PHP doesnt use C pointers, so when you said reference, I was expecting you to pass by reference in the function.
However, I dont see any passing by reference in your code snippet, be it in the function itself, or when calling the function.
2. If your "second screen mask result" is indeed the expected result, then I suggest that you learn HTML before learning PHP.
Your HTML code snippet is invalid.

My suggestion is also slight wrong, actually, I forgot to add in the function.
It should actually be:

$mask = 'theMask';
getMask($mask);
$myMask = $mask;
display (modify ($myMask));
$myMask2 = $mask
display (modify2($myMask2));

assuming that getMask() is something like:

function getMask(&$maskname) {
	//do something with $maskname
}

[cmerot]

the 'second screen mask result' is not what i am expecting ! what i expect is a well formated html select tag. ( :-) )

I guess the reference i am talking about is like that : http://www.php.net/manual/en/language.references.php
and the function i use is :
$xml -> getXMLBranch(); from active link xml package :
http://www.active-link.com/intranet/software.php

Actually i do :
$mask = $xmlObject -> getXMLBranch();

and if i modify $mask, then if i re-do
$mask2 = $xmlObject -> getXMLBranch();
then $mask2 is equivalent to $mask (that's the function property but not what i need)
That's why i think the getXMLBranch() function returns a reference, and that's why i am trying to copy not the reference, but the value of the reference, meaning that i could modify the value as many time as i want from a its original value.

Its quite difficult for me to talk in english, please excuse me about that.
And thanks for your help !

[Weedpacket]

If you're wanting two variables to point to the same thing (so that modifying the value of one changes the value returned for the other), then the operator for that is =&

$myMask =& $mask;
$myMask2 =& $mask;

(or $myMask = &$mask;, depending on how you prefer to think about what's going on.)

$foo =& $bar->something();

Fuller details are in the manual section you've found.

[laserlight]

hmm... but Weedpacket, he doesnt want to use the reference.

$mask = $xmlObject->getXMLBranch();
and
$mask2 = $xmlObject->getXMLBranch();

is the crux of the problem, I suppose.
From what I see, if $mask is changed, then $mask2 is assigned/initialized in that way, $mask != $mask2

The reason would lie in Weedpacket's post.

Of course, it is possible that the getXMLBranch() member function returns a reference, which is unusual coding practice in PHP IMO.
In that case, initialize a new object, then use the getXMLBranch() member function of that object, e.g. $xmlObject2

P.S.: hehe, I think in the &$varname way, Weedpacket 😃

[cmerot]

In that case, initialize a new object, then use the getXMLBranch() member function of that object, e.g. $xmlObject2

it should work, but not really a cool for CPU.

ok, because i cant reproduce getting a reference with a class method (!) here is the code i use in the real context :

<?
require 'xml/xml.php';
$XMLMask = new XML (join ( '', file ('mask.xml')));
# mask.xml is : 
#<mask-form>
#  ...
#  <mask name="resolution" type="select">
#    <select>
#      <option value="+">More than 1024*768</option>
#      <option value="1024">1024*768</option>
#      <option value="800">800*600</option>
#      <option value="-">Less than 800*600</option>
#    </select>
#  </mask>
#  ...
#</mask-form>

// from here are the 2 first pass of a loop. First for the max screen resolution, second for the screen resolution in use

$mask = $XMLMask -> getBranches('mask-form', 'mask', 'name', 'resolution');
$mask = $mask[0]; 
$option = $mask -> getBranches('mask/select', 'option', 'value', '-');
$option = $option[0];
$option -> setTagAttribute('selected', 'selected');
echo'<pre>' . htmlspecialchars($mask -> getXMLString(1)) . '<pre>';

# on screen there is :
#	<mask name="resolution" type="select">
#		<select>
#			<option value="+">More than 1024*768</option>
#			<option value="1024">1024*768</option>
#			<option value="800">800*600</option>
#			<option value="-" selected="selected">Less than de 800*600</option>
#		</select>
#	</mask>

$mask = $XMLMask -> getBranches('mask-form', 'mask', 'name', 'resolution');
$mask = $mask[0]; 
$option = $mask -> getBranches('mask/select', 'option', 'value', '+');
$option = $option[0];
$option -> setTagAttribute('selected', 'selected');
echo'<pre>' . htmlspecialchars($mask -> getXMLString(1)) . '<pre>';

# on screen there is :
#	<mask name="resolution" type="select">
#		<select>
#			<option value="+" selected="selected">More than 1024*768</option>
#			<option value="1024">1024*768</option>
#			<option value="800">800*600</option>
#			<option value="-" selected="selected">Less than 800*600</option>
#		</select>
#	</mask>

?>

[cmerot]

In that case, initialize a new object, then use the getXMLBranch() member function of that object, e.g. $xmlObject2

it should work, but not really a cool for CPU.

ok, because i cant reproduce getting a reference with a class method (!) here is the code i use in the real context :

<?
require 'xml/xml.php';
$XMLMask = new XML (join ( '', file ('ordi/mask.xml')));
# mask.xml is : 
#<mask-form>
#  ...
#  <mask name="resolution" type="select">
#    <select>
#      <option value="+">More than 1024*768</option>
#      <option value="1024">1024*768</option>
#      <option value="800">800*600</option>
#      <option value="-">Less than 800*600</option>
#    </select>
#  </mask>
#  ...
#</mask-form>

// from here are the 2 first pass of a loop, first for max sceen resolution, second for resolution in use

$mask = $XMLMask -> getBranches('mask-form', 'mask', 'name', 'resolution');
$mask = $mask[0]; // i expect only one issue
$mask -> setTagAttribute('name', 'maxRes', 'mask/select');
$option = $mask -> getBranches('mask/select', 'option', 'value', '-');
$option = $option[0];
$option -> setTagAttribute('selected', 'selected');
echo'<pre>' . htmlspecialchars($mask -> getXMLString(1)) . '<pre>';

# on screen there is :
#	<mask name="resolution" type="select">
#		<select>
#			<option value="+">More than 1024*768</option>
#			<option value="1024">1024*768</option>
#			<option value="800">800*600</option>
#			<option value="-" selected="selected">Less than de 800*600</option>
#		</select>
#	</mask>

$mask = $XMLMask -> getBranches('mask-form', 'mask', 'name', 'resolution');
$mask = $mask[0]; 
$mask -> setTagAttribute('name', 'resInUse', 'mask/select'); 
$option = $mask -> getBranches('mask/select', 'option', 'value', '+');
$option = $option[0];
$option -> setTagAttribute('selected', 'selected');
echo'<pre>' . htmlspecialchars($mask -> getXMLString(1)) . '<pre>';

# on screen there is :
#	<mask name="resolution" type="select">
#		<select>
#			<option value="+" selected="selected">More than 1024*768</option>
#			<option value="1024">1024*768</option>
#			<option value="800">800*600</option>
#			<option value="-" selected="selected">Less than 800*600</option>
#		</select>
#	</mask>

?>