Hello!
I'm currently working with sfMixer for the first time. I noticed that
when class A is extended with methods of class B, symfony always uses
the same instance of B, no matter which instance of A.
Let me explain: Think of the class structure as of the following
(sfMixer calls left away intentionally)
class A {}
class B
{
protected $var;
public function call($instance)
{
$this->var = rand(0,9999);
}
}
sfMixer::register('A', array('B', 'call'));
When you create two instances of A $a1 and $a2 and execute call() on
those two instances, both will have the same value of $var afterwards,
since they share the same instance of B.
In terms of multiple inheritance, this is not correct. Assuming we want
to inherit class A from class B and class C, this is not possible using
PHP alone. So we use the sfMixer to emulate the multiple inheritance. As
a conclusion, we want every instance of A to have its own properties,
whether inherited or not.
There actually is a solution for this problem: spl_object_hash(). This
function returns a unique hash for every object, that remains the same
during runtime. It could be used to create unique instances of B and C
for each instance of A (presuming that sfMixer registered object and not
class method calls). The only disadvantage is that spl_object_hash()
depends on PHP 5.2.0 (no disadvantage IMO, but speaking of the general
audience maybe...)
A temporary solution for this problem is to have $var as array and
register the objects oneself, but this gets ugly when working with many
different properties:
class B
{
protected $var1=array(), $var2=array(), ...
public function setVar1($instance, $value)
{
$this->var1[spl_object_hash($instance)] = $value;
}
public function setVar2($instance, $value)
{
$this->var2[spl_object_hash($instance)] = $value;
}
...
}
Can this fix be implemented in sfMixer although relying on PHP 5.2.0?
Regards
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