Custom CodeIgniter MY_Model

MY_Model.php

<?php

class MY_Model extends CI_Model{
	/**
   	 * The table name
   	 *
   	 * @var string
   	 * @access protected
   	 */
	protected $table = '';

    /**
     * The table's primary key
     *
     * @var string
     * @access protected
     */
	protected $primary_key = 'id';

	/**
     * The current object's id
     *
     * @var int
     * @access protected
     */
	protected $id = null;

	/**
     * The current object's data
     *
     * @var array
     * @access protected
     */
	protected $vals = array();

    /**
     * The table's field names
     *
     * @var array
     * @access protected
     */
	protected $fields = array();

    /**
     * The current object's data
     *
     * @var array
     * @access protected
     */
	protected $extra = array();

	/**
     * Constructor
     *
     * @access public
     */
	public function __construct($vals = NULL){
		parent::__construct();

		if($this->table != ''){
			$this->fields = $this->CI()->db->list_fields($this->table);
		}

		if(is_array($vals)) {
			$this->vals = array();

	        foreach($vals as $key => $value) {
    	        if(in_array($key, $this->fields)){
    	            $this->vals[$key] = $value;
    	        } else {
    	            $this->extra[$key] = $value;
    	        }
        	}

        	if(array_key_exists($this->primary_key, $this->vals)) {
            	$this->id = $this->vals[$this->primary_key];
        	}
		}
	}


  	/**
   	 * Function to access the CodeIgniter Instance
   	 *
   	 * @access public
   	 */
	public static function &CI() { return get_instance(); }

    /**
     * Insert entry into the database.
     *
	 * @return entry object
     * @access public
     */
	public function insert($parameters){
		if (!$this->CI()->db->table_exists($this->table)) {
			throw new Exception("Table does not exist.");
		} else {
			foreach($parameters as $key=>$param){
				if(!in_array($key, $this->fields)){
					unset($parameters[$key]);
				}
			}

			if($this->CI()->db->insert($this->table, $parameters)){
				$this->id = $this->CI()->db->insert_id();
				$query = $this->CI()->db->get_where($this->table, array($this->primary_key => $this->id));
				$result = $query->result_array();
				$result = $result[0];

				if($class = get_called_class()) {
        			$obj = new $class($result);
				
					return($obj);
				} else {
					throw new Exception("Model class not found.");
				}
			} else {
				throw new Exception("Could not insert into table.");
			}
		}
	}

    /**
     * Save current object to the database.
     *
     * @return entry object
     * @access public
     */
	public function save(){
		if($this->CI()->db->update($this->table, $this->vals, array($this->primary_key => $this->id))){
			if($query = $this->CI()->db->get_where($this->table, array($this->primary_key => $this->id))){
                $result = $query->result_array();
                $result = $result[0];

                if($class = get_called_class()) {
                    $obj = new $class($result);

                    return($obj);
                } else {
                    throw new Exception("Model class not found.");
                }
			} else {
				throw new Exception("Unable to find record.");
			}
		} else {
			throw new Exception("Unable to update record.");
		}
	}

    /**
     * Delete current object from the database.
     *
     * @return object
     * @access public
     */
	public function delete(){
        return $this->CI()->db->delete($this->table, array($this->primary_key => $this->id));
    }

    /**
     * Grab the total results of a find query.
     *
     * @return int
     * @access public
     */
	public function findCount($params = NULL){
		$response = $this->find($params, "COUNT(*) as count");
		return $response->extra['count'];
	}

    /**
     * Returns an array of objects based on given query parameters.
     *
     * @return object array
     * @access public
     */
	public function findAll($params = NULL, $fields = "*", $orderby = NULL, $groupby = NULL, $limit = NULL){
		if(isset($orderby) && $orderby != NULL){
            if(is_string($orderby)) {
                $this->CI()->db->order_by($groupby);
            } else if(is_array($orderby) || is_object($orderby)) {
				foreach((array)$orderby as $key=>$value){
	                $this->CI()->db->order_by($key, $value);
				}
            } else {
                throw new Exception("Invalid order by type.");
            }
        }

		if(isset($groupby) && $groupby != NULL){
			if(is_string($groupby)) {
				$this->CI()->db->group_by($groupby);
			} else if(is_array($groupby) || is_object($groupby)) {
				$this->CI()->db->group_by((array)$groupby);
			} else {
				throw new Exception("Invalid group by type.");
			}
		}

		if(isset($limit) && $limit != NULL){
			if(is_int($limit)) {
                $this->CI()->db->limit($limit);
            } else if(is_array($limit) || is_object($limit)) {
				$limit = (array)$limit;
                $this->CI()->db->limit($limit[0], $limit[1]);
            } else {
                throw new Exception("Invalid limit type.");
            }
		}

		if(!isset($fields) || $fields == NULL || $fields == "*"){
            $fields = "*";
			$this->CI()->db->select($fields);
        } else if(is_string($fields)) {
			$this->CI()->db->select($fields);
		} else if(is_array($fields)) {
			$fields = implode(",", $fields);
			$this->CI()->db->select($fields);
		} else {
			throw new Exception("Invalid fields type.");
		}

		if(!isset($params) || $params == NULL){
			$query = $this->CI()->db->get($this->table);
		} else if(is_scalar($params)) {
            $query = $this->CI()->db->get_where($this->table, array($this->primary_key => $params));
            $this->id = $params;
        } else if(is_array($params) || is_object($params)) {
            $query = $this->CI()->db->get_where($this->table, (array)$params);
        } else {
            throw new Exception("Invalid primary key type.");
        }

        if($query->num_rows > 0){ 
            $results = $query->result_array();
			$objects = array();

			foreach($results as $result){
            	if($class = get_called_class()) {
                	$obj = new $class($result);

                	$objects[] = $obj;
            	} else {
               		throw new Exception("Model class not found.");
            	}
			}

			return $objects;
        } else {
            return false;
        }
	}

    /**
     * Return an object containing one result based on the given query.
     *
     * @return object
     * @access public
     */
	public function find($params = NULL, $fields = NULL){
		if(!isset($fields) || $fields == NULL || $fields == "*"){
            $fields = "*";
            $this->CI()->db->select($fields);
        } else if(is_string($fields)) {
            $this->CI()->db->select($fields);
        } else if(is_array($fields)) {
            $fields = implode(",", $fields);
            $this->CI()->db->select($fields);
        } else {
            throw new Exception("Invalid fields type.");
        }

		if(!isset($params) || $params == NULL){
            $query = $this->CI()->db->order_by($this->primary_key." DESC")->limit(1)->get($this->table);
        } else if(is_scalar($params)) {
			$query = $this->CI()->db->get_where($this->table, array($this->primary_key => $params));
			$this->id = $params;
		} else if(is_array($params) || is_object($params)) {
			$query = $this->CI()->db->get_where($this->table, (array)$params);
		} else {
			throw new Exception("Invalid primary key type.");
		}
		
		if($query->num_rows > 0){
			$result = $query->result_array();
			$result = $result[0];

			if($class = get_called_class()) {
				$obj = new $class($result);

				return($obj);
			} else {
				throw new Exception("Model class not found.");
			}
		} else {
			return false;
		}
	}

    /**
     * Set data array values.
     * Reference: http://php.net/manual/en/language.oop5.overloading.php
     *
     * @access public
     */
	public function __set($name, $value) {
		if(array_search($name, $this->fields) !== FALSE) {
      		$this->vals[$name] = $value;

      		if($name == $this->primary_key)
        		$this->id = $value;

      		return;
    	}

    	$this->$name = $value;
  	}

    /**
     * Get values from the data array.
     * Reference: http://www.php.net/manual/en/language.oop5.overloading.php#97918
     *
     * @return reference value
     * @access public
     */
	public function &__get($name) {
		$f = null;

    	if(array_search($name, $this->fields) !== FALSE) {
      		return $this->vals[$name];
		} else {
			return $f;
		}
  	}
}

Made a fork to add an update function similar to save. Instead of doing updates by changing values one by one the update function takes an array param to effect the changes