[PHP] OOP, dynamic class extention
I want to be able to set a base class in a settings file, and then have other
classes extend the base class, but PHP won't let me do what I have tried.
I get the following error:
Fatal error: Class cepweb: Cannot inherit from undefined class my_base_class
in /home/me/my_child_class.php on line 10
ex:
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends MY_BASE_CLASSFILE {
// yada yada
}
?
Any thoughts on ways to overcome this?
I have tried using a variable instead of a constant, but it didn't work.
-Jackson
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Re: [PHP] OOP, dynamic class extention
Shouldn't this line:
class my_child_class extends MY_BASE_CLASSFILE {
Read like this:
class my_child_class extends MY_BASE_CLASS {
After all base_class.php isn't the name of your class, base_class is.
Jackson Miller [EMAIL PROTECTED] wrote:
I want to be able to set a base class in a settings file, and then have other
classes extend the base class, but PHP won't let me do what I have tried.
I get the following error:
Fatal error: Class cepweb: Cannot inherit from undefined class my_base_class
in /home/me/my_child_class.php on line 10
ex:
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends MY_BASE_CLASSFILE {
// yada yada
}
?
Any thoughts on ways to overcome this?
I have tried using a variable instead of a constant, but it didn't work.
-Jackson
--
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Re: [PHP] OOP, dynamic class extention
php is not c, you can't use constants this way.
Jackson Miller wrote:
I want to be able to set a base class in a settings file, and then have other
classes extend the base class, but PHP won't let me do what I have tried.
I get the following error:
Fatal error: Class cepweb: Cannot inherit from undefined class my_base_class
in /home/me/my_child_class.php on line 10
ex:
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends MY_BASE_CLASSFILE {
// yada yada
}
?
Any thoughts on ways to overcome this?
I have tried using a variable instead of a constant, but it didn't work.
-Jackson
--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] OOP, dynamic class extention
On Thursday 30 October 2003 12:29 pm, Marek Kilimajer wrote:
php is not c, you can't use constants this way.
but why? Is there a work around?
-Jackson
Jackson Miller wrote:
I want to be able to set a base class in a settings file, and then have
other classes extend the base class, but PHP won't let me do what I have
tried.
I get the following error:
Fatal error: Class cepweb: Cannot inherit from undefined class
my_base_class in /home/me/my_child_class.php on line 10
ex:
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends MY_BASE_CLASSFILE {
// yada yada
}
?
Any thoughts on ways to overcome this?
I have tried using a variable instead of a constant, but it didn't work.
-Jackson
--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] OOP, dynamic class extention
Why? I guess because php is interpreted language and is parsed only
once, no preprocessor. Workaround is quite easy, use variable:
?php
// settings to be set on install of the app
$MY_BASE_CLASS=base_class;
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends $MY_BASE_CLASS {
// yada yada
}
?
Jackson Miller wrote:
On Thursday 30 October 2003 12:29 pm, Marek Kilimajer wrote:
php is not c, you can't use constants this way.
but why? Is there a work around?
-Jackson
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Re: [PHP] OOP, dynamic class extention
On Thursday 30 October 2003 01:27 pm, Marek Kilimajer wrote:
Why? I guess because php is interpreted language and is parsed only
once, no preprocessor. Workaround is quite easy, use variable:
I thought that too, and tried it before posting to the list (it was at the
bottom of my first email).
Unfortunately when you do that you get and expecting T_STRING error. The same
thing happens if you put the var in quotes.
Why would it not parse the constant the first time? It does everywhere else.
-Jackson
?php
// settings to be set on install of the app
$MY_BASE_CLASS=base_class;
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends $MY_BASE_CLASS {
// yada yada
}
?
Jackson Miller wrote:
On Thursday 30 October 2003 12:29 pm, Marek Kilimajer wrote:
php is not c, you can't use constants this way.
but why? Is there a work around?
-Jackson
--
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Re: [PHP] OOP, dynamic class extention
Jackson Miller wrote: On Thursday 30 October 2003 01:27 pm, Marek Kilimajer wrote: Why? I guess because php is interpreted language and is parsed only once, no preprocessor. Workaround is quite easy, use variable: I thought that too, and tried it before posting to the list (it was at the bottom of my first email). Can you show it once again. In your first email you use a constant, not variable. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] OOP, dynamic class extention
On Thursday 30 October 2003 02:15 pm, Marek Kilimajer wrote:
Can you show it once again. In your first email you use a constant, not
variable.
Sure. In my first email I said that I had tried with a variable too (but
didn't show the code).
Ex1 gives a cannot inherit from undefined class error
Ex2 gives a parse error, expecting T_STRING
Ex1 (with constants):
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends MY_BASE_CLASS {
// yada yada
}
?
Ex2 (with variables):
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
$my_base_class_var = MY_BASE_CLASS;
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends $my_base_class_var {
// yada yada
}
?
Also, just to be clear:
base_class.php
?php
class base_class {
function base_class() {
echo it works;
return true;
}
}
?
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Re: [PHP] OOP, dynamic class extention
Hey guys, you can extend a _class_ from an existing _class_ but not from
a _string_constant_ (Ex1 - MY_BASE_CLASS is evaluated to constant of
type string) neither from a _string_variable_ (Ex2 - $my_base_class_var
is a variable of type string).
To be able to use different base classes with the same name just change
the reference to the different settings files that contain the class
declared with the same name but with different functionality, perhaps in
the following way:
?php
$a = 1;
// blah blah
if ($a==1) {
include_once(settingsfile1.php);
} else {
inclide_once(settingsfile2.php);
}
?
Or even (much) better create a single base class in a single
configuration file and different modified instances of that class used
for each of the different configurations you may have.
Boyan
Jackson Miller wrote:
On Thursday 30 October 2003 02:15 pm, Marek Kilimajer wrote:
Can you show it once again. In your first email you use a constant, not
variable.
Sure. In my first email I said that I had tried with a variable too (but
didn't show the code).
Ex1 gives a cannot inherit from undefined class error
Ex2 gives a parse error, expecting T_STRING
Ex1 (with constants):
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends MY_BASE_CLASS {
// yada yada
}
?
Ex2 (with variables):
?php
// settings to be set on install of the app
define(MY_BASE_CLASS,base_class);
define(MY_BASE_CLASSFILE,base_class.php);
$my_base_class_var = MY_BASE_CLASS;
// require the class file
require_once(MY_BASE_CLASSFILE);
class my_child_class extends $my_base_class_var {
// yada yada
}
?
Also, just to be clear:
base_class.php
?php
class base_class {
function base_class() {
echo it works;
return true;
}
}
?
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