class can not inherit from another class, why ?

[lawrence]

Is this a valid class definition?

class McBase {

// 06-14-04 - I may or may not later add something here. This will
// be the top of the PDS content management system hierarchy. I'm
// leaving it blank for now but want it here for future flexibility.

}


I use it later on this line:

class McBasic extends McBase {
but I get this error:

Fatal error: Class mcbasic: Cannot inherit from undefined class mcbase
in /usr/local/www/vhosts/publicpen.com/htdocs/designer/ppKernel/McBasic.php
on line 5

[Michael Fesser]

.oO(lawrence)

Is this a valid class definition?

class McBase {
[...]
Yes.
I use it later on this line:

class McBasic extends McBase {
but I get this error:

Fatal error: Class mcbasic: Cannot inherit from undefined class mcbase
in /usr/local/www/vhosts/publicpen.com/htdocs/designer/ppKernel/McBasic.php
on line 5

The question is: Are both classes stored in the same file? Apparently
not. So you have to include the base-class before you can extend it,
e.g.

require_once 'mcbase.php';

class McBasic extends McBase {...}

HTH
Micha

[lawrence]

Michael Fesser <ne*****@gmx.ne t> wrote in message

Fatal error: Class mcbasic: Cannot inherit from undefined class mcbase
in /usr/local/www/vhosts/publicpen.com/htdocs/designer/ppKernel/McBasic.php
on line 5

The question is: Are both classes stored in the same file? Apparently
not. So you have to include the base-class before you can extend it,
e.g.

require_once 'mcbase.php';

Thanks. Now I got it working. But McBasic doesn't seem to have its
constructor called when it is the parent of another class. I've been
trying to test, as you'll see here:

class McBasic extends McBase {
var $controllerForA ll = null;
var $resultsObject = null;
var $notifyObject = null;
var $historyObject = null;

/**
*
*
* 06-14-04 - most objects in the PDS content management system should
be
* descended from McBasic. This provides basic servies to all its
child
* classes. All the classes that themselves contain no other objects
can
* safely be put here, and then become services available to all child
* classes.
*
*
*
*
*/
function McBasic() {
// a test for debugging
echo "hello<br>" ;
$this->controllerForA ll = & getController() ;

if (is_object($thi s->controllerForA ll)) {
echo "this is an object";
} else {
echo "this is not an object";
}
$this->resultsObjec t = &
$this->controllerForA ll->getObject("McR esults", " in the constructor
of McBasic.");
$this->notifyObject = &
$this->controllerForA ll->getObject("McN otify", " in the constructor of
McBasic.");
$this->historyObjec t = &
$this->controllerForA ll->getObject("McH istory", " in the constructor
of McBasic.");
}
}



But in the class McArrangements, I have this line:

class McArrangements extends McBasic {

Yes McArrangements throws an error whenever I use the 4 objects that
are set in the constructor of McBasic. The error says that there is no
such object. For instance, I get an error on this line in
McArrangements:

$this->resultsObjec t->error("In setControlPanel CbId(), in the class
McArrangements, we expected the method's parameter to be a number, but
instead we got this: $cbId ", "McArrangements ");
So I decided to write a test for McBasic, and the test revealed that
everything was working for McBasic. In the test, I call McBasic
directly, and at the end of the constructor I test to see if
$this->resultsObjec t is an object. It tests true. Yet when I refer to
$this->resultsObjec t in McArrangements, I get "No such object". How
can this be?

[Berislav Lopac]

lawrence wrote:

Thanks. Now I got it working. But McBasic doesn't seem to have its
constructor called when it is the parent of another class. I've been
trying to test, as you'll see here:
<snip>
So I decided to write a test for McBasic, and the test revealed that
everything was working for McBasic. In the test, I call McBasic
directly, and at the end of the constructor I test to see if
$this->resultsObjec t is an object. It tests true. Yet when I refer to
$this->resultsObjec t in McArrangements, I get "No such object". How
can this be?

Are you using PHP5? Try using _construct().

According to the Zend articles, the old way of defining constructors should
work as well, but there might be some problems when calling parent's
contructor.

Berislav

[Berislav Lopac]

Berislav Lopac wrote:

lawrence wrote:

Thanks. Now I got it working. But McBasic doesn't seem to have its
constructor called when it is the parent of another class. I've been
trying to test, as you'll see here:

<snip>

So I decided to write a test for McBasic, and the test revealed that
everything was working for McBasic. In the test, I call McBasic
directly, and at the end of the constructor I test to see if
$this->resultsObjec t is an object. It tests true. Yet when I refer to
$this->resultsObjec t in McArrangements, I get "No such object". How
can this be?

Are you using PHP5? Try using _construct().

Oops, that should be __construct() (two underscores).

Berislav

[Phil Powell]

lk******@geocit ies.com (lawrence) wrote in message news:<da******* *************** ****@posting.go ogle.com>...

Michael Fesser <ne*****@gmx.ne t> wrote in message

Fatal error: Class mcbasic: Cannot inherit from undefined class mcbase
in /usr/local/www/vhosts/publicpen.com/htdocs/designer/ppKernel/McBasic.php
on line 5

The question is: Are both classes stored in the same file? Apparently
not. So you have to include the base-class before you can extend it,
e.g.

require_once 'mcbase.php';

Thanks. Now I got it working. But McBasic doesn't seem to have its
constructor called when it is the parent of another class. I've been
trying to test, as you'll see here:

[snip]

If you're running PHP 4+ and not PHP 5 use the parent keyword to run
the parent's constructor in the child's constructor:

[PHP]
class Parent {

function Parent() {
// DO STUFF HERE
}

}

class Child extends Parent {

function Child() {
parent::Parent( );
}

}
[/PHP]

Phil

[lawrence]

so*****@erols.c om (Phil Powell) wrote in message news:<1c******* *************** ***@posting.goo gle.com>...

lk******@geocit ies.com (lawrence) wrote in message news:<da******* *************** ****@posting.go ogle.com>...

Michael Fesser <ne*****@gmx.ne t> wrote in message

>Fatal error: Class mcbasic: Cannot inherit from undefined class mcbase
>in /usr/local/www/vhosts/publicpen.com/htdocs/designer/ppKernel/McBasic.php
>on line 5

The question is: Are both classes stored in the same file? Apparently
not. So you have to include the base-class before you can extend it,
e.g.

require_once 'mcbase.php';

Thanks. Now I got it working. But McBasic doesn't seem to have its
constructor called when it is the parent of another class. I've been
trying to test, as you'll see here:

[snip]

If you're running PHP 4+ and not PHP 5 use the parent keyword to run
the parent's constructor in the child's constructor:

[PHP]
class Parent {

function Parent() {
// DO STUFF HERE
}

}

class Child extends Parent {

function Child() {
parent::Parent( );
}

}
[/PHP]

Phil

The parent keyword! I'd never heard of that! That is a terrific tip,
thanks much.

I got it work like this: McArrangements had a constructor that wasn't
doing much, just setting a variable that could be set elsewhere. So I
rewrote it and deleted the constructor. Suddenly the constructor of
McBasic was called. So, I reasoned, if you want to have the
constructor of a parent class called, you are not allowed to have a
constructor in the child class. But now I see that, quite reasonably,
there is a way to call parent constructors, and still have the child
have a constructor. Very good!