Posted by AlexVN on 12/02/90 11:50

Henk,

Thank you for the great answer. You are right--I'm looking for a method
of instantiating class with dynamic parameters, not creating. I
understant the method you proposed, but what I would much rather see is
a method of calling class constructor with dynamic number of
parameters. I suspect that PHP does not have such method (since you, a
guru, do not listed it here) and will try to create a couple of ifs for
my case.

Thanks,
Alexander
http://www.alexatnet.com/

Henk Verhoeven wrote:
> Hi Alexander,
>
> Your message seems somewhat mixed-up. As far as i know the only way to
> create a class is to have php interpret a class definition like:
>
> class MyClass extends MySuperclass {
> //variables and methods go here
> }
>
> As far as i know the following does not work:
>
> $className = 'MyClass';
> $superclassName = 'MySuperclass';
> class $className extends $superclassName {
> //variables and methods go here
> }
> (please correct me if i am wrong - if this actually would work!)
>
> Furthermore you can call static methods as well as instance methods
> using call_user_func_array according to the explanation of the the
> callback type:
> - Static class methods can also be passed without instantiating an
> object of that class by passing the class name instead of an object as
> the element with index 0.
> - A method of an instantiated object is passed as an array containing an
> object as the element with index 0 and a method name as the element with
> index 1.
>
> Finally you can do is INSTANTIATE a class dynamicly:
> $myClassName = 'MyClass';
> $newObject = new $myClassName($param1, $param2);
> I agree this does nog allow you to pass the parameters as an array.
> Is that what you want?
>
> You ARE allowed to pass more parameters then the constructor of the
> class needs. You could write a function like this that will pass a
> limited number of parameters from an array:
>
> function instantiate_array($className, $parameters) {
> if (count($parameters) > 4)
> trigger_error('too many parameters', E_USER_ERROR);
> for ($i=0; $i<4; $i++) {
> $varName = "p$i";
> if (isSet($parameters[$i]);
> $$varName = $parameters[$i]
> else
> $$varName = null;
> }
> return new $className($p0, $p1, $p2, $p3);
> }
>
> I agree this does have an if statement, but at least if you need more
> parameters, you do not need to add more if statments.
> (Possible disadvantage: the null values that are passed may override
> defaults defined in the constructors parameter list)
>
> Greetings,
>
> Henk Verhoeven,
> www.phpPeanuts.org.
>
>
> AlexVN wrote:
> > Hi,
> >
> > I would like to know if someone investigated the method of creating
> > classes dynamically depending on the name. I do not like a lot of ifs
> > and I suppose that something like call_user_func_array('ClassName',
> > array($param1, $param2, $param3, ..., $paramN)) should exist over the
> > PHP language. Any suggestions?
> >
> > Thanks,
> > Alexander
> > http://www.alexatnet.com/
> >

[Back to original message]