Re: [PHP] accessing variables within objects

Here's the PHP doc page.
Let us know if you have more questions:
http://us3.php.net/manual/en/language.oop5.overloading.php

Thank you,
Micah Gersten
onShore Networks
Internal Developer
http://www.onshore.com



Philip Thompson wrote:
On Jul 30, 2008, at 1:29 PM, Jim Lucas wrote:

Marten Lehmann wrote:
Hello,
I'm using some php-classes which worked fine with php-5.0.4. Now I
tried to upgrade to php-5.2.6, but the classes give a lot of errors.
If I set
error_reporting(E_ALL);
I see messages like
Notice: Undefined property: FastTemplate::$main in
/whereever/inc.template.php on line 293
Notice: Undefined property: current_session::$cust_id in
/whereever/inc.init.php on line 117
In inc.template.php there are a lot of calls like $this->$key. In
inc.init.php there are calls like $session->cust_id.

to fix these errors, you would need to modify the code so it does
something like this.

where it calls $this->$key you need to check and make sure that $key
exists before you trying call for it.

So something like this would work.

if ( isset( $this->$key ) ) {
$this->$key;
} else {
$this->$key = null;
}

You didn't show any context in which you are using the above code. So
I don't know what will actually work in your situation. Show a
little more code that includes the method in which $this->$key is
called.

You will want to look at using the Overloading feature of PHP5.
Check out this page for overloading examples

http://us2.php.net/manual/en/language.oop5.overloading.php

Take note of the __get() and __set() methods. The __get method
checks to see if the key exists before it tries working with it.

Ok, I'm trying to understand the point to using these overloading
methods.

<?php
$obj = new ClassThatUsesOverloading ();
$obj->hi = 'Hi';
$obj->bye = 'Bye';

echo $obj->hi, ' ', $obj->bye;
// Output: Hi Bye
?>

You could have done that or you could do the following.....

<?php
$obj = new ClassThatDoesntUseOverloading ();
$obj->setHi('Hello');
$obj->setBye('Bye Bye!');

echo $obj->hi(), ' ', $obj->bye();
// Output: Hello Bye Bye!
?>

The 2nd way seems more *OOP* than the first - weird to explain. I
guess what I'm wanting to know is.... why would you use overloading
(in PHP)? The only reason I can think of is to avoid having to
create/use accessors. Please help me understand! But please be nice! =D

Thanks,
~Philip


What has changed in php-5.2.x so that these calls don't work any
more? What is the new, required form to use objects in a similar
manner (unfortunately I have no ressources to code these classes
from scratch)? Thanks.
Kind regards
Marten

.

Relevant Pages

  • Re: [PHP] accessing variables within objects
    ... I got the link the first time and read the page. ... You will want to look at using the Overloading feature of PHP5. ...
    (php.general)
  • Re: [PHP] accessing variables within objects
    ... Philip Thompson wrote: ... You will want to look at using the Overloading feature of PHP5. ... This would get rid of a lot of your NOTICEs from PHP. ... "Some men are born to greatness, some achieve greatness, ...
    (php.general)
  • Re: [PHP] accessing variables within objects
    ... You will want to look at using the Overloading feature of PHP5. ... $obj = new ClassThatDoesntUseOverloading; ...
    (php.general)
  • Re: Object of class Person could not be converted to string
    ... the language had been better planned from the start. ... Implement operator overloading in its entirety and allow the base ... of PHP 5, __toStringmethod is used if applicable. ... variable type in a string context, you can no longer do that. ...
    (comp.lang.php)
  • Re: [PHP] accessing variables within objects
    ... You will want to look at using the Overloading feature of PHP5. ... This would get rid of a lot of your NOTICEs from PHP. ... I would add a method something like the following to your class and it should fix the problems with trying to access properties that do not exist. ...
    (php.general)