class inside another class - PHP 4

[R]

Hello.

I've got a strange situation.
I've got class Handlers it's only:

class Handlers
{
var $DB;
var $XML;
}

In my PHP script I want to do sth like this:

$Main = new Handlers();
$Main->DB = new DataBase();
$Main->XML = new XML();

but when inside eg. CreateNode method in XML class I want to run query
using: $this->DB->RunQuery();
it's of course fatal error...

I saw in one script that such classes
can be created but i don't remember where I found it...

Can it be writen in PHP 4?

thanks in advance

--
best regards
R

[Matthias Esken]

Re: class inside another class - PHP 4

R wrote:
[color=blue]
> using: $this->DB->RunQuery();
>
> [...]
>
> Can it be writen in PHP 4?[/color]

This works with PHP5. The solution for PHP4 is:

$db = &$this->DB;
$db->RunQuery();

Regards,
Matthias

[Zurab Davitiani]

Re: class inside another class - PHP 4

Matthias Esken wrote:
[color=blue]
> R wrote:
>[color=green]
>> using: $this->DB->RunQuery();
>>
>> [...]
>>
>> Can it be writen in PHP 4?[/color]
>
> This works with PHP5. The solution for PHP4 is:
>
> $db = &$this->DB;
> $db->RunQuery();[/color]

There's nothing wrong with
$this->DB->RunQuery();
syntax in PHP4 as long as DB is a property and not a method.

[Michael Fesser]

Re: class inside another class - PHP 4

.oO(Matthias Esken)
[color=blue]
>R wrote:
>[color=green]
>> using: $this->DB->RunQuery();
>>
>> [...]
>>
>> Can it be writen in PHP 4?[/color]
>
>This works with PHP5. The solution for PHP4 is:
>
> $db = &$this->DB;
> $db->RunQuery();[/color]

The above also works in PHP4. DB is a property, not a method.

The OP's problem is that $this always points to the object that calls
the method, inside the XML-methods it points to $XML, not to the parent
object. The XML-object can't directly access the methods of the DB-
object because it simply doesn't know about it.

One possible solution would be to implement a class method that returns
the required object:

PHP4:

$db = &Handlers::getI nstance('DB');
$db->RunQuery();

PHP5:

Handlers::getIn stance('DB')->RunQuery();

HTH
Micha

[R]

Re: class inside another class - PHP 4

Zurab Davitiani wrote:
[color=blue]
> There's nothing wrong with
> $this->DB->RunQuery();
> syntax in PHP4 as long as DB is a property and not a method.[/color]

OK.

But I'm sure, that I saw in one PHP 4 script that such methods where used.
I used them by myself $this->Class1->ItsMethod() syntax inside eg.
$this->Class2->ItsMethod()

I used such object some time ago but I forgot the URL... I tried to
google but I failed

thanks in advance for Your help

--
best regards
R