PHP4: How can I keep includes from redefinig clases?

eantoranz · 01-18-2006, 01:37 PM

I have a small project. I have a number of files that define different classes.

The problem is like this:

A requires B and C
B requires D
C requires D

as I'm defining a class in D, it is telling me that I can't redefine the class in file D. How can I keep this from happening?

eantoranz · 01-18-2006, 01:48 PM

To be precise:
d.php

defines class DBConection

m.php

defines class Model

s.php

includes d.php
defines class S that extends DBConection

r.php

includes s.php, m.php
defines R that extends Model

p.php

includes s.php, r.php

when I ask to run p.php (from console) I get a message that says that I can't redefine DBConnection.

keefaz · 01-18-2006, 01:48 PM

I don't see the code, but maybe you could use another class name in D or
use require_once() instead of require() to include required files

I see your new post now

do you extends your DBConnection class in p.php ?

eantoranz · 01-18-2006, 02:21 PM

No. I don't extend it in p.php.

and now DBConnection is not extended in s.php either.... but the same problem is still there.

include_once let me advance, but then it said at some points that a class that was defined in the "included_once" file wasn't defined.

I think the problem is the "double" inclusion of s.php.

Is there a way to check for the existence of a class and if it exists, ask php to return? Maybe I can do that in the files that are going to be required more than once in a single run (like s.php, or d.php).

eantoranz · 01-18-2006, 03:01 PM

It's not elegant, but it seems to solve the problem. Where d.php starts:

Code:

if (isset($ConexionDBDefined)) {
	return(0);
}
$ConexionDBDefined = true;

eantoranz · 01-18-2006, 03:06 PM

Now it says there's one undefined class. I'll have to rethink about it... maybe php5?

I'll try later tonight.

graemef · 01-18-2006, 05:01 PM

Replace you include with include_once. That should do the trick.