Cfrtjryk

I wrote a code that should help me fetch app lists from my database (set by different tables by their category - Microsoft Office apps, Other apps, System apps, ect').
I will add my class structure, and would like a review mainly for the architecture.
I'm not sure if I'm using the interface properly, if I even should use it like this. and if my way of extending the main class was done properly.

Firstly, I defined an interface:

Interface AppList {





    // For getting lists from the database 

    public function getList();



    // For Adding a new app to the list

    public function addToList(); 



    // For removing an app from the list

    public function removeFromList(); 

}

Then I implement in a main class named "AppList" which is my main list class:

class Static_list implements AppList {





    protected $db;

    protected $table;





    public function __construct() {

        // get db instance

        $this->db           = Database::getInstance();

    }





    /**

     *

     *  Gets the list by (table) name 

     *  @param      $table      String          Gets a name of a table (list)

     *  @throws                 Array/Boolian   Returns an array of apps(/rows) 

     *

     */

    public function getList() {



        // SELECT * FROM $this->table 

    }





    /**

     *

     *  Adds a new app to the app lits - by (table) name 

     *  @param      $table      String      Gets a name of a table (list)

     *  @param      $contents   Array       Gets an array of contents to apply in input. 

     *  @throws                 Boolian     Returns "ture" if successful, "false" if not (for mainly )

     *

     */

    public function addToList() {



        // INSERT INTO $this->table ( field1, field2,...fieldN ) VALUES ( $contents[1], $contents[2],...$contents[N] );

    }





    /**

     *

     *  Removes a new app to the app lits - by (table) name 

     *  @param      $table      String      Gets a name of a table (list)

     *  @param      $id         Init        App ID to remove 

     *  @throws                 Boolian     Returns "ture" if successful, "false" if not (for mainly )

     *

     */

    public function removeFromList($id) {



        // DELETE FROM $this->table WHERE id = $id;

    }



}

As mentioned before, each list has a different table ('ms_app_list' db table, 'other_app_list' db table, 'system_app_list' db table, ect')
So for each table I'm going to have a different class that extends the main "AppList" class.

class Ms_app_list extends Static_list {



    private $table = 'ms_app_list'; 

}



class Other_app_list extends Static_list {



    private $table = 'other_app_list'; 

}



class System_app_list extends Static_list {



    private $table = 'system_app_list'; 

}

So then if I want to print_r() my "system apps list", I just:

$sys_apps = new System_app_list(); 

print_r($sys_apps->getList());

Is the interface not relevant for my case? At the beginning I was thinking this was irrelevant since I use them in the main class(Static_list) and ill work without the interface too, but isn't this considered a "good practice" for code where more than one developer works on?

Should every list be a separate class that implements the interface, and extending a main class is a bad practice?

Example for only one list:

class Ms_app_list implements AppList {



    private $table  = 'ms_app_list'; 

    private $db; 



    public function __construct() {

        // get db instance

        $this->db           = Database::getInstance();

    }



    public function getList() {



        // SELECT * FROM $this->table 

    }



    public function addToList() {



        // INSERT INTO $this->table ( field1, field2,...fieldN ) VALUES ( $contents[1], $contents[2],...$contents[N] );

    }



    public function removeFromList($id) {



        // DELETE FROM $this->table WHERE id = $id;

    }



}

I decided to use one main class (Static_list) with the 3 "must included methods" and extend the class to other 3 lists classes to prevent code repetition.