Extend CI AR functions (In this case extending join() clause to handle Postgres type casting, eg. variabe::int )

gistfile1.txt

-------------------------------
/application/core/MY_Loader.php
-------------------------------

<?php (defined('BASEPATH')) OR exit('No direct script access allowed');
 
class MY_Loader extends CI_Loader {
 
		 /**
		 * Database Loader
		 *
		 * @access    public
		 * @param    string    the DB credentials
		 * @param    bool    whether to return the DB object
		 * @param    bool    whether to enable active record (this allows us to override the config setting)
		 * @return    object
		 */
		function database($params = '', $return = FALSE, $active_record = NULL)
		{
				// Grab the super object
				$CI =& get_instance();
 
				// Do we even need to load the database class?
				if (class_exists('CI_DB') AND $return == FALSE AND $active_record == NULL AND isset($CI->db) AND is_object($CI->db)) 
				{
					return FALSE;
				}
 
				// Check for MY_DB in application/core
				$my_db = config_item('subclass_prefix').'DB';
				
				$my_db_file = APPPATH.'core/'.$my_db.EXT;
				
				if(file_exists($my_db_file))
				{
					require_once($my_db_file);
				}
				else
				{
					require_once(BASEPATH.'database/DB'.EXT);
				}

				// Load the DB class
				$db =& DB($params, $active_record);
 
				// Check for a custom db driver
				$my_driver = config_item('subclass_prefix').'DB_'.$db->dbdriver.'_driver';
				
				$my_driver_file = APPPATH.'core/'.$my_driver.EXT;
 
				if (file_exists($my_driver_file)) 
				{
						require_once($my_driver_file);

						$db = new $my_driver(get_object_vars($db));
				}
 
				if ($return === TRUE) 
				{
						return $db;
				}
 
				// Initialize the db variable.  Needed to prevent
				// reference errors with some configurations
				$CI->db = '';
				$CI->db = $db;
		}
}

---------------------------
/application/core/MY_DB.php
---------------------------

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

function &DB($params = '', $active_record_override = NULL)
{
	// Load the DB config file if a DSN string wasn't passed
	if (is_string($params) AND strpos($params, '://') === FALSE)
	{
		// Is the config file in the environment folder?
		if ( ! defined('ENVIRONMENT') OR ! file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/database.php'))
		{
			if ( ! file_exists($file_path = APPPATH.'config/database.php'))
			{
				show_error('The configuration file database.php does not exist.');
			}
		}
 
		include($file_path);
 
		if ( ! isset($db) OR count($db) == 0)
		{
			show_error('No database connection settings were found in the database config file.');
		}
 
		if ($params != '')
		{
			$active_group = $params;
		}
 
		if ( ! isset($active_group) OR ! isset($db[$active_group]))
		{
			show_error('You have specified an invalid database connection group.');
		}
 
		$params = $db[$active_group];
	}
	elseif (is_string($params))
	{
 
		/* parse the URL from the DSN string
		 *  Database settings can be passed as discreet
		 *  parameters or as a data source name in the first
		 *  parameter. DSNs must have this prototype:
		 *  $dsn = 'driver://username:password@hostname/database';
		 */
 
		if (($dns = @parse_url($params)) === FALSE)
		{
			show_error('Invalid DB Connection String');
		}
 
		$params = array(
							'dbdriver'	=> $dns['scheme'],
							'hostname'	=> (isset($dns['host'])) ? rawurldecode($dns['host']) : '',
							'username'	=> (isset($dns['user'])) ? rawurldecode($dns['user']) : '',
							'password'	=> (isset($dns['pass'])) ? rawurldecode($dns['pass']) : '',
							'database'	=> (isset($dns['path'])) ? rawurldecode(substr($dns['path'], 1)) : ''
						);
 
		// were additional config items set?
		if (isset($dns['query']))
		{
			parse_str($dns['query'], $extra);
 
			foreach ($extra as $key => $val)
			{
				// booleans please
				if (strtoupper($val) == "TRUE")
				{
					$val = TRUE;
				}
				elseif (strtoupper($val) == "FALSE")
				{
					$val = FALSE;
				}
 
				$params[$key] = $val;
			}
		}
	}
 
	// No DB specified yet?  Beat them senseless...
	if ( ! isset($params['dbdriver']) OR $params['dbdriver'] == '')
	{
		show_error('You have not selected a database type to connect to.');
	}
 
	// Load the DB classes.  Note: Since the active record class is optional
	// we need to dynamically create a class that extends proper parent class
	// based on whether we're using the active record class or not.
	// Kudos to Paul for discovering this clever use of eval()
 
	if ($active_record_override !== NULL)
	{
		$active_record = $active_record_override;
	}
 
	require_once(BASEPATH.'database/DB_driver.php');

	if ( ! isset($active_record) OR $active_record == TRUE)
	{
		// Check for a custom active record class in application/core
		$my_active_record = config_item('subclass_prefix').'DB_active_rec';
	
	   	$my_active_record_file = APPPATH.'core/'.$my_active_record.EXT;

		if (file_exists($my_active_record_file))
		{
			require_once(BASEPATH.'database/DB_active_rec.php');
			
			require_once($my_active_record_file);
			
			if ( ! class_exists('CI_DB'))
			{
				eval('class CI_DB extends '.config_item('subclass_prefix').'DB_active_record { }');
			}
		}
		else
		{
			require_once(BASEPATH.'database/DB_active_rec.php');

			if ( ! class_exists('CI_DB'))
			{
				eval('class CI_DB extends CI_DB_active_record { }');
			}
		}
 
	}
	else
	{
		if ( ! class_exists('CI_DB'))
		{
			eval('class CI_DB extends CI_DB_driver { }');
		}
	}
 
	require_once(BASEPATH.'database/drivers/'.$params['dbdriver'].'/'.$params['dbdriver'].'_driver.php');
 
	// Instantiate the DB adapter
	$driver = 'CI_DB_'.$params['dbdriver'].'_driver';

	$DB = new $driver($params);
 
	if ($DB->autoinit == TRUE)
	{
		$DB->initialize();
	}
 
	if (isset($params['stricton']) && $params['stricton'] == TRUE)
	{
		$DB->query('SET SESSION sql_mode="STRICT_ALL_TABLES"');
	}
 
	return $DB;
}

--------------------------------------
/application/core/MY_DB_active_rec.php
--------------------------------------

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 
class MY_DB_active_record extends CI_DB_active_record {
 
	/**
	* Join
	*
	* Generates the JOIN portion of the query
	*
	* @param	string
	* @param	string	the join condition
	* @param	string	the type of join
	* @return	object
	*/
	public function join($table, $cond, $type = '')
	{
		if ($type != '')
		{
			$type = strtoupper(trim($type));

			if ( ! in_array($type, array('LEFT', 'RIGHT', 'OUTER', 'INNER', 'LEFT OUTER', 'RIGHT OUTER')))
			{
				$type = '';
			}
			else
			{
				$type .= ' ';
			}
		}

		// Extract any aliases that might exist.  We use this information
		// in the _protect_identifiers to know whether to add a table prefix
		$this->_track_aliases($table);

		// 1. if $cond contains :: chars then separate code with it
		// 2. if not, use the default preg_match

		if( strpos($cond, '::') > 0)
		{
			if (preg_match('/([\w\.]+)([\W\s]+)(.+)/', $cond, $match))
			{				
				// 1. extract typecast from $match[3]
				$t = explode('=', $match[3]);
				$typecast = trim($t[0]);
				// 2. remove 'typecast =' from $match[3]
				$match[3] = trim($t[1]);				
				// 3. replace $match[2] content with =
				$match[2] = ' = ';

				$match[1] = $this->_protect_identifiers($match[1]);
				$match[3] = $this->_protect_identifiers($match[3]);

				// 4. add :: and typecast to the end of $match[1]
				$match[1] .= '::'.$typecast;

				$cond = $match[1].$match[2].$match[3];
			}	
		}
		else
		{	// Strip apart the condition and protect the identifiers
			if (preg_match('/([\w\.]+)([\W\s]+)(.+)/', $cond, $match))
			{
				$match[1] = $this->_protect_identifiers($match[1]);
				$match[3] = $this->_protect_identifiers($match[3]);

				$cond = $match[1].$match[2].$match[3];

				//debug($cond);
			}
		}		

		// Assemble the JOIN statement
		$join = $type.'JOIN '.$this->_protect_identifiers($table, TRUE, NULL, FALSE).' ON '.$cond;

		$this->ar_join[] = $join;
		if ($this->ar_caching === TRUE)
		{
			$this->ar_cache_join[] = $join;
			$this->ar_cache_exists[] = 'join';
		}

		return $this;
	}
 
}
 
/* End of file MY_DB_active_rec.php */
/* Location: ./application/core/MY_DB_active_rec.php */