Validating Input Data with the CodeIgniter PHP Framework - Listing the enhanced version of the generic model class

Undeniably, the best way to help you understand how the generic model works is by showing you its complete signature. With that idea in mind, below I listed the entire source code corresponding to the “AbstractModel” class, naturally including the recently implemented “validate()” method. Here it is for you:

abstract class MY_Model extends Model

{

protected $table = ''; // table associated to the model

protected $fields = array(); // fields of table associated to the model

protected $id = NULL; // value of the primary key of the table associated to the model

protected $data = array(); // model input data

protected $insertID = NULL; // insertion ID

protected $numRows = NULL; // number of rows returned by SELECTS

protected $validation = array(); // model validation rules

protected $errors = array(); // model errors

/**

* Constructor

*

* @access protected

*/

protected function __construct()

{

parent::Model();

// get CI super object as a model property

$this->ci =& get_instance();

}

/**

* Sets associated table data for the model

*

* @author Alejandro Gervasio

* @return void

* @access public

*/

public function setTableData($table = 'default')

{

if ($this->db->table_exists($table))

{

$this->table = $table;

$this->fields = $this->db->field_names($this->table);

}

}

/**

* Sets value of primary key of the associated table for the model

*

* @author Alejandro Gervasio

* @param integer

* @return void

* @access public

*/

public function setID($id)

{

$this->id = is_integer($id) AND $id > 0 ? $id : 1;

}

/**

* Gets value of primary key of the associated table for the model

*

* @author Alejandro Gervasio

* @return integer

* @access public

*/

public function getID()

{

return $this->id;

}

/** Sets input data for the model

*

* @author Alejandro Gervasio

* @param array

* @return void

* @access public

*/

public function setData($data)

{

if ( is_array($data) AND count($data) > 0)

{

foreach ($data as $key => $value)

{

if (array_search($key, $this->fields) === FALSE)

{

unset($data[$key]);

}

}

$this->data = $data;

}

}

/**

* Sets validation rules for model data

*

* @author Alejandro Gervasio

* @param array

* @return void

* @access public

*/

public function setValidation($validation)

{

if ( is_array($validation) AND count($validation) > 0)

{

foreach ($validation as $field => $rule)

{

if (array_search($field, $this->fields) === FALSE)

{

unset($validation[$key]);

}

}

$this->validation = $validation;

}

}

/**

* Returns a result set with specified fields according to given conditions.

*

* @author Alejandro Gervasio

* @return query result on success - Boolean FALSE on failure

* @access public

*/

public function fetch($fields = '*', $where = NULL, $order = 'id ASC', $limit = NULL, $offset = 0, $join = NULL)

{

if ($fields != '*')

{

$this->db->select($fields);

}

if ($this->id != NULL)

{

$this->db->where('id', $this->id);

}

elseif($where != NULL)

{

$this->db->where($where);

}

if ($order != 'id ASC')

{

$this->db->orderby($order);

}

if ($limit != NULL)

{

$this->db->limit($limit, $offset);

}

if( $join != NULL)

{

$this->db->join($join);

}

$query = $this->db->get($this->table);

$this->numRows = $query->num_rows();

if ($this->numRows > 0)

{

return ($this->numRows > 1 ) ? $query->result() : $query->row();

}

$this->errors[] ='No rows were returned by the query.';

return FALSE;

}

/** Saves model data into associated table (validation rules are applied to input data)

*

*

* @author Alejandro Gervasio

* @return integer on success - Boolean FALSE on failure

* @access public

*/

public function save()

{

if ($this->data == NULL)

{

$this->errors[] = 'Error saving row.';

return FALSE;

}

// validate input data

if( !$this->validate())

{

return FALSE;

}

// Insert new row if ID was not set in the model

if ($this->id == NULL)

{

$this->db->insert($this->table, $this->data);

$this->insertID = $this->db->insert_id();

return $this->insertID;

}

// Otherwise update existing row

else

{

$this->db->where('id', $this->id)->update($this->table, $this->data);

return $this->db->affectedRows;

}

}

/** Deletes model data from associated table (validation rules are applied to input data)

*

*

* @author Alejandro Gervasio

* @return Boolean TRUE on success - Boolean FALSE on failure

* @access public

*/

public function delete()

{

if ($this->id == NULL)

{

$this->errors[] = 'Error deleting row.';

return FALSE;

}

$this->db->where('id', $this->id)->delete($this->table);

return TRUE;

}

/**

* Validates model input data

*

* @author Alejandro Gervasio

* @return Boolean TRUE on success - FALSE on failure

* @access protected

*/

protected function validate()

{

// If no validation rules or no model were provided data set appropriate error

if (count($this->validation) === 0)

{

$this->errors[] = 'No validation rules were set for the model.';

return FALSE;

}

// Loads CI validation library

$this->ci->load->library('validation');

// Load CI language file for validation

$this->ci->lang->load('validation');

// resets error messages

$this->errors = array();

foreach ($this->validation as $field => $rules)

{

$expRules = explode('|', $rules);

// if the field is not required check next one

if (! in_array('required', $expRules, TRUE))

{

continue;

}

// Iterates through the validation rules

foreach ($expRules as $rule)

{

// Removes the parameter from the rule (when specified)

$param = FALSE;

if (preg_match("/(.*?)[(.*?)]/", $rule, $match))

{

$rule = $match[1];

$param = $match[2];

}

// Calls the validation method that corresponds to the rule

if (method_exists($this->ci->validation, $rule))

{

$result = $this->ci->validation->$rule($this->data[$field], $param);

}

else

{

// Tries to run a native PHP function if method of CI validation class doesn't exist

if (function_exists($rule))

{

$result = $rule($this->data[$field]);

}

}

// if an offending field was found store error message in error array

if ($result === FALSE)

{

$this->errors[] = sprintf($this->ci->lang->line($rule),$field);

}

}

}

return (count($this->errors)) === 0 ? TRUE : FALSE;

}

}

Despite the rather lengthy signature of the above model class, at this point its underlying logic should be pretty easy to grasp, since each of its methods have been discussed in depth in distinct articles of the series. Of course, the model can always be improved, so feel free to introduce into it your own enhancements, which will surely help you to sharpen your existing PHP skills.

In this sixth episode of the series, I explained how to implement a protected method within the generic model class, which permits us to perform custom validation on the incoming data used for the model when it executes insert and update operations against its associated database table.

In the upcoming tutorial, things will get really interesting. I’m going to complete the development of the model class, and in consequence, you’ll have an opportunity to see for yourself how to use it in the context of a real MySQL-driven application. Thus, now that you’ve been warned about the subject of the next article, you don’t have any excuses to miss it!