Pass Instance of Class in Function Call

[MikeBronner]

I must be having a brain-fart or something. Something I know I have done in the past is giving me problems today and I can't get my head around it. (Must be one of those days ...)

Here's my situation: I want to pass the instance of a class (my db abstraction class) into another class, like so:

$myClass->set_database($r_database);

Now, in myClass I consume it like so:

class myClass
{
    private $r_db = null;
    [...]
    public function set_database($r_db)
    {
        $this->$r_db = $r_db;
    }
    [...]
}

In the set-method it gives me the following error:

PHP Notice: Object of class Database to string conversion in myClass.php on line 38

Where line 38 is

$this->$r_db = $r_db;

I'm stumped! Anyone know a way out? Oh, and if I do this in PHP 5.2.0 it returns the new error:

PHP Catchable fatal error: Object of class Database could not be converted to string in myClass.php on line 38

Take Care,
Mike

 

[sleipnir214]

Weird. I can't duplicate that error using test code.



Want the best answers? Ask the best questions! TANSTAAFL!

 

[MikeBronner]

What version of PHP are you using?

Take Care,
Mike

 

[sleipnir214]

I tested with 5.1.6 then upgraded to 5.2.0.

Neither version displayed the error. Here's my test code:

<?php
class Database
{
        var $foo;

        function Database ()
        {
                $this->foo = 3;
        }
}

class myClass
{
        private $r_db = null;

        function myClass ()
        {
                $this->r_db = '';
        }

        public function set_database($r_db)
        {
                $this->r_db = $r_db;
        }
}

$a = new Database();

$myClass = new myClass();

$myClass->set_database($a);
?>

Want the best answers? Ask the best questions! TANSTAAFL!

 

[MikeBronner]

Hmm, thanks for trying that. Of course the code I posted is extremely simplified, so I wonder if there's something else than the passing that is causing this.

Take Care,
Mike

 

[sleipnir214]

Nearly certainly. The operative question is, "Why would PHP find it necessary to try to convert the Database class to a string?"



Want the best answers? Ask the best questions! TANSTAAFL!

 

[MikeBronner]

Well, here's the code to my database class. I can't see anything out of the ordinary. Mayhap a second pair of eyes helps here:

	class Database
	{
/**
* @access private
* @var string Username used to access the database.
*/
		private	$_s_username	= '';
/**
* @access private
* @var string Password used to access the database.
*/
		private	$_s_password	= '';
/**
* @access private
* @var string Identifies database to be used.
*/
		private	$_s_database	= '';
/**
* @access private
* @var string Identifies server to connect to.
*/
		private	$_s_server		= '';
/**
* @access private
* @var string Database type. Default is mssql.
*/
		private $_s_type		= '';
/**
* @access private
* @var resource Contains connection resource for database.
*/
		private $_r_connection	= null;

/**
* Constructor method that will default the database connection to host
* to either csdbbcdev001 or csdbbmsql001 (development or production)
* if any of the parameters are left blank (excluding type).
*
* @access public
* @todo Complete exception handling functionality in try-catch blocks.
* @param string $username Sting that determines the LDAP server to connect to.
* @param string $password Sting that determines the LDAP server to connect to.
* @param string $database Sting that determines the LDAP server to connect to.
* @param string $server Sting that determines the LDAP server to connect to.
* @param string $type Determines database type. Can be fbsql, ibase, mssql, mysql, mysqli, oci8, pgsql, querysim, or sqlite.
* @author Mike Bronner <michael.g.bronner@kp.org>
* @version 1
*/
		public function __construct($username = null, $password = null, $database = null, $server = null, $type = null)
		{
			try
			{
				if ((strlen($username) == 0)
					|| (strlen($password) == 0)
					|| (strlen($database) == 0)
					|| (strlen($server) == 0))
				{
					$this->_s_username = 'web';
					$this->_s_password = 'web';
					$this->_s_database = 'case_coordination_center';
					if (strtolower($_SERVER['COMPUTERNAME']) == 'csdbbcccw001') {$this->_s_server = 'csdbbmsql001';}
//					else {$this->_s_server = 'csdbbcdev001';}
					else {$this->_s_server = 'CSDBBCDEV001\SQLEXPRESS';}
				}
				else
				{
					$this->_s_username = $username;
					$this->_s_password = $password;
					$this->_s_database = $database;
					$this->_s_server = $server;
				}
				if (strlen($type) == 0) {$this->_s_type = 'mssql';}
				else {$this->_s_type = $type;}
			}
			catch(exception $error)
			{
			}
		}
		
/**
* Destructor method that will disconnect the database and clear any residual objects from memory.
*
* @access public
* @todo Complete exception handling functionality in try-catch blocks.
* @author Mike Bronner <michael.g.bronner@kp.org>
* @version 1
*/
		public function __destruct()
		{
			if ($this->_r_connection) {$this->_r_connection->disconnect();}
			$this->_r_connection	= null;
			$this->_s_database		= null;
			$this->_s_password		= null;
			$this->_s_server		= null;
			$this->_s_type			= null;
			$this->_s_type			= null;
			$this->_s_username		= null;
		}
		
/**
* Method that is called internally when needed to connect to the database. Each method in the class will
* connect, perform its actions against the database, then disconnect again.
*
* @access private
* @todo Complete exception handling functionality in try-catch blocks.
* @author Mike Bronner <michael.g.bronner@kp.org>
* @version 1
*/
		private function connect()
		{
			$dsn = '';
			
			try
			{
				$dsn = $this->_s_type . '://' . $this->_s_username . ':' . $this->_s_password . '@' . $this->_s_server . '/' . $this->_s_database;
				$db =& MDB2::factory($dsn, array('debug' => 2,'result_buffering' => false));
				if (PEAR::isError($db)) {throw new Exception($db->getMessage());}
				else
				{
					$this->_r_connection = $db;
					return true;
				}
			}
			catch(exception $error)
			{
				return false;
			}
		}
		
/**
* Wrapper method that is called internally when needed to disconnect from the database. Each method in the 
* class will connect, perform its actions against the database, then disconnect again.
*
* @access private
* @todo Complete exception handling functionality in try-catch blocks.
* @author Mike Bronner <michael.g.bronner@kp.org>
* @version 1
*/
		private function disconnect()
		{
			$this->_r_connection->disconnect();
		}
		
/**
* Method that is used to run a query.
*
* @access public
* @todo Complete exception handling functionality in try-catch blocks.
* @author Mike Bronner <michael.g.bronner@kp.org>
* @return resource Recordset object.
* @version 1
*/
		public function query($query_string)
		{
			$r_recordset = null;
			
			try
			{
				$this->connect();
				$r_recordset = $this->_r_connection->query($query_string);
				if (PEAR::isError($r_recordset)) {throw new Exception($r_recordset->getDebugInfo());}
				
				return $r_recordset;
			}
			catch (Exception $error)
			{
				return false;
			}
			$this->disconnect();
		}
		
/**
* Method that is used to run DML, like inserts, updates, deletes.
*
* @access public
* @todo Complete exception handling functionality in try-catch blocks.
* @author Mike Bronner <michael.g.bronner@kp.org>
* @return resource Recordset object.
* @version 1
*/
		public function execute($query_string)
		{
			$r_result = null;

			try
			{
				$this->connect();
				$r_result = $this->_r_connection->exec($query_string);
				if (PEAR::isError($r_result)) {throw new Exception($r_result->getDebugInfo());}
				
				return $r_result;
			}
			catch (Exception $error)
			{
				return false;
			}
		}
		
		public function execute_stored_procedure($s_stored_procedure, $a_parameters, $a_datatypes = null)
		{
			$r_resultset = null;
			
			try
			{
				$this->connect();
				$this->_r_connection->loadModule("Function");
				$r_resultset = $this->_r_connection->executeStoredProc($s_stored_procedure, $a_parameters, $a_datatypes, true, true);
				if (MDB2::isError($r_resultset))
				{
echo 'Standard Message: ' . $r_resultset->getMessage() . "<br />";
echo 'Standard Code: ' . $r_resultset->getCode() . "<br />";
echo 'DBMS/User Message: ' . $r_resultset->getUserInfo() . "<br />";
echo 'DBMS/Debug Message: ' . $r_resultset->getDebugInfo() . "<br />";
   				}
			}
			catch (exception $error)
			{
				return false;
			}
			
			return $r_resultset;
		}
	}

Take Care,
Mike