Dynamic function for edit table DB (postgresql many to many) by PHP CI

update.php

<?php 
	/**
	 * -- Many to Many -- 
	 * [processing the reference table to communicate with the database]
	 * @param  string  $key          [pk of the table] *name of primary keys
	 * @param  string  $pk 			 [reference pk to main table] *value of primary keys
	 * @param  array   $data         [data to be executed]
	 * @param  integer $method       [execution method] 0 insert, 1 update
	 * @return boolean               [success = true]
	 *
	 * OnGoing FUNC
	 */
	private function __reference_table_processing($key = "", $pk = "", $data = [], $method = 0) {
		// parameters for the query
		$direct_batch = array("is_batch" => true, "is_direct" => true); // CI models
		$permanent = array("is_permanently" => true); // CI models

		// total data
		$total_data = count($data);

		// prepare data
		for ($n = 0; $n < $total_data; $n++) {
			$data_reference[] = array(
					$key => $data[$n], 'source_primary_keys' => $pk
			);
		}

		// check the destination !! get table from pk
		switch ($key) {
			case "destination_primary_keys":
				$table = "destination_table_name";
			break;
			#
			#
			#
			# .. add for more
			default:
				return FALSE
				break;
		}

		// on update
		if ($method === 1) {
			// delete before insert
			$condition = array("destination_pk" => $pk);
			$this->_dm->set_model($table)->delete($condition, $permanent); // CI models
		}

		// not empty data on insert
		if (!empty($data_reference)) {
			// insert !! reference table
			$this->_dm->set_model($table)->insert($data_reference, $direct_batch); // CI models
		}

		// return
		return true;
	}