On Wed, 2004-03-31 at 12:55, Jonathan Pitcher wrote:
> I have been writing OOP programs for the past couple years.  Over these 
> years I have run into the same problem, I have solved the problem in 
> many different ways.  I was wondering if there is a recommended way to 
> solve the problem I have listed below.
> 
> To keep it simple, lets say I have 3 classes.  A main class, an error 
> class and a log class.
> 
> The classes are laid out as:
> 
>                MAIN
>                    |
>        ----------------
>        |                    |
> ERROR          LOG
> 
> 
> Now I want error to write a message to the log file.
> 
> Solution 1
> 
>        Store the Main class in a Session variable. And the access the 
> Log through main.
> 
>       $_SESSION["Main"]->Log->Write_Error("My Error");
> 
> Solution 2
> 
>       Almost the same as above.  I store main in a Session Variable but 
> the I create a global function to access log.
> 
>        function Write_Error($Message)
>        {
>               $_SESSION["Main"]->Log->Write_Error($Message);
>       }
> 
>       This ways saves coding time because I don't have to write out the long 
> session reference.
> 
> 
> I know there are more ways to do this.  But every way I can think of 
> requires you to store the main class in a session variable to access 
> log.  Is there a way to access a parent class or a parents parent 
> without doing what I did above ?

You can use a base object service class. The InterJinn framework uses
this method to access all such classes. In this way a single common and
inheritable method can be used to retrieve singleton objects, or to act
as a factory. This provides loose coupling for any given object from the
consumer of it's services. For instance:

class Exception extends BaseClass
{
    function triggerError( $errorMsg )
    {
        // Some erroneous condition.

        $log = &$this->getServiceRef( 'log' );
        $log->log( $errorMsg );
    }
}

InterJinn does a lot of things behind the scenes in the getService()
method such as lazy loading of the source code, and lazy instantiation
of the object. This way unused services have a minimal impact on
application's performance when they are not actually needed. Hope this
helps you with your question.

Cheers,
Rob.
-- 
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| InterJinn Application Framework - http://www.interjinn.com |
:------------------------------------------------------------:
| An application and templating framework for PHP. Boasting  |
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| such as forms, properties, sessions, and caches. InterJinn |
| also provides an extremely flexible architecture for       |
| creating re-usable components quickly and easily.          |
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