__construct & require_once()

[L4DD13]

Hi,

can you not use a require_once within the __construct() function of a class when the required script it set as a variable (i.e. require_once($this->_db_connection_vars))
Thanks.

[AnthonySterling]

Sure, require_once() should be fine with a __construct, why do you think it wouldn't be?

[L4DD13]

Sure, require_once() should be fine with a __construct, why do you think it wouldn't be?

I think it because it works when i define the script but not when i use a variable

[AnthonySterling]

Does the variable have scope within the class? Could you post a quick sample?

[L4DD13]

This is the class

class __cms{

    // Define variables for use with cms
    private $_hDB; // use for connection to mysql server
    public $_root;
    public $_urlroot;
    public $_mysql_connection_vars;
    
    public function __construct(){
        
        require_once($this->_mysql_connection_vars);
        
    }

} 

This is the script requesting the class

$_cms = new __cms();
    $_cms->_mysql_connection_vars = '../dbsettings.php'; 

[AnthonySterling]

You are setting the path for $_mysql_connection_vars AFTER the class is instantiated, __construct runs once you specify 'new __cms' and at that point, $_mysql_connection_vars has no value.

[AnthonySterling]

An alternative would be:-

<?php
class __cms
{
    // Define variables for use with cms

    private $_hDB; // use for connection to mysql server

    public $_root;

    public $_urlroot;

    public $_mysql_connection_vars;

    

    public function __construct( $dbPath )
    {
        $this->_mysql_connection_vars = $dbPath;
        require_once($this->_mysql_connection_vars);    
    }

} 

new __cms( '../dbsettings.php' );

?>

[L4DD13]

Ah, i didnt think of that lol, thanks.

[AnthonySterling]

No worries, although , if your trying to create a OOP CMS maybe you should be passing your Database object to the CMS?

[L4DD13]

No worries, although , if your trying to create a OOP CMS maybe you should be passing your Database object to the CMS?

Hi,
What do you mean?

Thanks.

[AnthonySterling]

Whilst there is a lot to go into when creating an application like this, you would ideally want to create separate objects for say ''Database','Settings','Template' and such...

It would allow you to change a certain object without changing any of the other object, say moving from MySQL to Oracle, or from Smarty to your own templating engine.

Here is a very crass, rough and dirty example.

<?php
class Database
{
    private $oHandle;
    
    public function __construct( $sHost, $sUser, $sPass, $sName, $iPort )
    {
        $this->oHandle = new mysqli( $sHost, $sUser, $sPass, $sName, $iPort );
    }
    
    public function query( $sSQL )
    {
        return $this->oHandle->query( $sSQL );
    }
    
    public function escape( $sValue )
    {
        return $this->oHandle->real_escape_string( $sValue );
    }
}

class CMS
{
    protected $oDatabase;
    
    public function __construct(Database $oDatabase)
    {
        $this->oDatabase = $oDatabase;
    }
    
    public function getUserDetails( $iID )
    {
        $oResult = $this->oDatabase->query(sprintf("SELECT username,password,name,sex FROM users WHERE id = %s;",(Integer)$iID));
        /*
        //--> Do stuff with result and return array.
        */
    }
}

//--> Usage
try
{
    $oDatabase = new Database( 'myserver','me','mypassword','cms_db',3306 );
    $oCMS = new CMS( $oDatabase );
}
catch( Exception $oException )
{
    die('Sorry, there is no database connection at this time.');
}
?>