PHP - Oophp Class Structure

Hi all.

I have some questions in reference to using OOPHP.  All of my programming thus far has been procedural and that's worked out great for me, but there's (obviously) a huge market for OOP.  I'm confused on how to apply the OOP concepts to what I'm already doing procedurally (or if OOP even applies to what I'm doing).  A lot of what I do is PHP/MySQL, so how do I apply OOP concepts to that relationship?  At what point do things become objects that should be put into a class?

I found this example but it seems excessive compared to writing only a  simple connection function
http://forum.ragezone.com/f427/simple-oophp-mysql-connection-679020/

When having different levels of directories, using relative paths will not work anymore, for example:


controller
- authentication

File 1: include('../../model/header.php')



model

File 2: header.php



view

File 3. style.css



The header.php file includes the css file with a relative path, but the problem is it includes it as follows: ../view/style.css


When now the header.php file gets included into File 1 in the folder "authentication", then the css file will not be accessible anymore, for it to be accessible you would have to go two directories up.

In this sense my question is, what would be the proper path structure for a folder structure with multiple levels? Should I rather use absolute paths, I am not so prone of absolute path. What if the folders changes a bit, or the domain changes, or the location changes?

Hi all.

I'm just getting my feet wet with OOPHP.  My question is "why have a setter method when you can just use the __construct method to set everything?" and "would you need a separate setter method for each attribute of an object?"(i.e. set_first, set_last, set_gender, etc.)

The code...

<?php

class person{

var $first;

var $last;

var $gender;

function __construct($first,$last,$gender){

$this->first=$first;

$this->last=$last;

$this->gender=$gender;

}

function set_first($new_name){

$this->first=$new_name;

}

function get_person(){

return $this->first . $this->last . $this->gender;

}

}
?>

I have mysqli object in Database class base:

[color=]database class:[/color]

class Database {
  private $dbLink = null;
  
  public function __construct() {
    if (is_null($this->dbLink)) {
      // load db information  to connect
      $init_array = parse_ini_file("../init.ini.inc", true);
      $this->dbLink = new mysqli($init_array['database']['host'],
                           $init_array['database']['usr'],
                           $init_array['database']['pwd'],
                           $init_array['database']['db']);
  
      if (mysqli_connect_errno()) {
        $this->dbLink = null;
      }
    }
  }

  public function __destruct() {
    $this->dbLink->close();
  }
}


Class derived is Articles where I use object dBLink in base (or parent) class and I can't access to mysqli methods (dbLink member of base class):

Articles class:

require_once ('./includes/db.inc');

class Articles extends Database{
  private $id,
              ....
              ....
             $visible = null;
  
  public function __construct() {
    // Set date as 2009-07-08 07:35:00
    $this->lastUpdDate = date('Y-m-d H:i:s');
    $this->creationDate = date('Y-m-d H:i:s');
  }
  
  // Setter
  ....
  ....

  // Getter
  ....
  ....

  public function getArticlesByPosition($numArticles) {
    if ($result = $this->dbLink->query('SELECT * FROM articles ORDER BY position LIMIT '.$numArticles)) {
      $i = 0;
      while ($ret = $result->fetch_array(MYSQLI_ASSOC)) {
        $arts[$i] = $ret;
      }
      $result->close();
      return $arts;
    }
  }
}


In my front page php I use article class:


include_once('./includes/articles.inc');
$articlesObj = new articles();
$articles = $articlesObj->getArticlesByPosition(1);
var_dump($articles);


[color=]Error that go out is follow[/color]

Notice: Undefined property: Articles::$dbLink in articles.inc  on line 89

Fatal error: Call to a member function query() on a non-object in articles.inc on line 89

If I remove constructor on derived class Articles result don't change 
Please help me

If a class has a constructor but also has a static method, if I call the static method does the constructor run so that I can use an output from the constructor in my static method?

--Kenoli