Okay, I was obviously on something; of course you'd get a 
call-time-blah-blah error with our current syntax. But using &$this 
with call_user_func_array() works fine.

Fine for me then.

No, that's how you need to wrap objects if you want a reference in an 
array. The array is what's being passed to the function.

Doesn't this produce call-time pass-by-reference notices?

Sure, but I'm not sure why that's a problem. Any other opinions here? Jan?

That works, but you'll always get a reference. Here's an example:



function foo($x)

{

     $x = 42;

}

function bar(&$x)

{

     $x = 43;

}

$y = 0;

call_user_func('foo', &$y);

print "$y\n"; # -> 42

call_user_func('bar', &$y);

print "$y\n"; # -> 43



If the function is called directly you can decide in the hook function 
whether you'd like to get a reference or a copy:



function foo($x)

{

     $x = 42;

}

function bar(&$x)

{

     $x = 43;

}

$y = 0;

foo($y);

print "$y\n"; # -> 0

bar($y);

print "$y\n"; # -> 43



I don't know what's more sensible in this case.

True, but it's also useful to be able to modify the object, and part 
of the reason the $this parameter was added. Can you test with using 
&$this instead of $this with the call_user_func syntax?

On my way back home after work it crossed my mind that I could 
subclass Turba's LDAP driver instead of "abusing" the encode hooks to 
set additional LDAP attributes. I think that subclassing the LDAP 
driver is a much better solution since it doesn't require any changes 
to Horde. I'm sorry for bothering you!

The hook functions _turba_hook_encode_{attribute} and 
_turba_hook_decode_{attribute} always get a copy of the Turba object 
since the hook functions are called with call_user_func. It's not 
possible to get a reference to the object and thus it isn't possible 
to modify the object in the hook function.



For example, I'd like to concatenate the first name and last name and 
store that value in the attributes "displayname" and "cn". I'd also 
like to construct the "postalAddress" from "street", "postalCode", 
"location" etc.



This is only possible if I can get a reference to the Turba object 
instead of a copy. Here's an example hook function:



function _turba_hook_encode_firstname($new_value, $old_value, &$turba_object)

{

     $firstname = $new_value;

     $lastname = $turba_object->getValue('firstname');

     $name = $firstname . ' ' . $lastname;

     $turba_object->setValue('displayname', $name);

     $turba_object->setValue('cn', $name);

     return $new_value;

}



I've attached a small patch that replaces call_user_func in 
turba/lib/Object.php with direct function calls.



It's highly unlikely that this change will break existing hook 
functions. I don't think that anyone has requested a reference to the 
Turba object but then expects to get a copy of the object.