Creating objects with variable parameters in contructor

[zimba]

Hello,

Do you know a better way to :
- instanciate a class with an unknown number of parameters in the
constructor
- call an object's method, also with an unknown number of parameters

?

The following solution works, but it's around 20 times slower than
normally.
This is why I'm looking for another solution... :p

Cheers,
zimba

<?php

function createObject($className, $parameters)
{
$c_params = count($parameters);
$c = "return new $className(";
for($i=0; $i<$c_params; $i++)
{
$c .= "\$parameters[$i]";
if ($i<$c_params-1) $c .= ',';
}
$c .= ');';
return eval($c);
}

function callMethod($object, $methodName, $parameters)
{
$c_params = count($parameters);
$c = "return \$object->$methodName(";
for($i=0; $i<$c_params; $i++)
{
$c .= "\$parameters[$i]";
if ($i<$c_params-1) $c .= ',';
}
$c .= ');';
return eval($c);
}

class MyClass
{
private $a, $b;
function __construct($a, $b)
{
$this->a = $a;
$this->b = $b;
}
function out($x, $y)
{
return $this->a .' '. $this->b . ' and '.$x .' '.$y;
}
}

$x = createObject('MyClass', array('hello', 'world'));
echo callMethod($x, 'out', array('you','also'));

?>

[Janwillem Borleffs]

zimba wrote:

Do you know a better way to :
- instanciate a class with an unknown number of parameters in the
constructor
- call an object's method, also with an unknown number of parameters

Just use a constructor with a variable number of arguments and use
func_num_args()/func_get_args() to get the (total number of) arguments.
JW

[zimba]

This is not what I mean't,
the object can be arbitrary of any kind, so I don't know in advance how
much parameters it will have in the constructor.

[Henk Verhoeven]

Hi Zimba,

Take a look at http://nl.php.net/manual/en/function...func-array.php
it says:
If you need to call CLASS method (NOT object):
call_user_func_array(array('class', 'Foo'),$args);

If you program the constructors yourself, consider to give all
constuctors a single parameter, expected to be an array that holds the
actual values you would otherwise pass as parameters, that may run
faster, especially if you pass the array by reference.

Greetings,

Henk Verhoeven,
www.phpPeanuts.org.

zimba wrote:

Hello,

Do you know a better way to :
- instanciate a class with an unknown number of parameters in the
constructor
- call an object's method, also with an unknown number of parameters

?

The following solution works, but it's around 20 times slower than
normally.
This is why I'm looking for another solution... :p

Cheers,
zimba

<?php

function createObject($className, $parameters)
{
$c_params = count($parameters);
$c = "return new $className(";
for($i=0; $i<$c_params; $i++)
{
$c .= "\$parameters[$i]";
if ($i<$c_params-1) $c .= ',';
}
$c .= ');';
return eval($c);
}

function callMethod($object, $methodName, $parameters)
{
$c_params = count($parameters);
$c = "return \$object->$methodName(";
for($i=0; $i<$c_params; $i++)
{
$c .= "\$parameters[$i]";
if ($i<$c_params-1) $c .= ',';
}
$c .= ');';
return eval($c);
}

class MyClass
{
private $a, $b;
function __construct($a, $b)
{
$this->a = $a;
$this->b = $b;
}
function out($x, $y)
{
return $this->a .' '. $this->b . ' and '.$x .' '.$y;
}
}

$x = createObject('MyClass', array('hello', 'world'));
echo callMethod($x, 'out', array('you','also'));

?>