Element_OphDrPrescription_Details::updateItems PHP Method

    public function updateItems($items)
    {
        $itemCount = count($items);
        if ($itemCount == 0) {
            throw new Exception('Item cannot be blank.');
        } else {
            if (!$this->id) {
                throw new Exception('Cannot call updateItems on unsaved instance.');
            }
            // Get a list of ids so we can keep track of what's been removed
            $existing_item_ids = array();
            $existing_taper_ids = array();
            // can't rely on relation, as this will have been set already
            foreach (OphDrPrescription_Item::model()->findAll('prescription_id = :pid', array(':pid' => $this->id)) as $item) {
                $existing_item_ids[$item->id] = $item->id;
                foreach ($item->tapers as $taper) {
                    $existing_taper_ids[$taper->id] = $taper->id;
                }
            }
            // Process (any) posted prescription items
            foreach ($items as $item) {
                if (isset($item['id']) && isset($existing_item_ids[$item['id']])) {
                    // Item is being updated
                    $item_model = OphDrPrescription_Item::model()->findByPk($item['id']);
                    unset($existing_item_ids[$item['id']]);
                } else {
                    // Item is new
                    $item_model = new OphDrPrescription_Item();
                    $item_model->prescription_id = $this->id;
                    $item_model->drug_id = $item['drug_id'];
                }
                // Save main item attributes
                $item_model->dose = $item['dose'];
                $item_model->route_id = $item['route_id'];
                if (isset($item['route_option_id'])) {
                    $item_model->route_option_id = $item['route_option_id'];
                } else {
                    $item_model->route_option_id = null;
                }
                $item_model->frequency_id = $item['frequency_id'];
                $item_model->duration_id = $item['duration_id'];
                if (isset($item['continue_by_gp'])) {
                    $item_model->continue_by_gp = $item['continue_by_gp'];
                } else {
                    $item_model->continue_by_gp = 0;
                }
                $item_model->save();
                // Tapering
                $new_tapers = isset($item['taper']) ? $item['taper'] : array();
                foreach ($new_tapers as $taper) {
                    if (isset($taper['id']) && isset($existing_taper_ids[$taper['id']])) {
                        // Taper is being updated
                        $taper_model = OphDrPrescription_ItemTaper::model()->findByPk($taper['id']);
                        unset($existing_taper_ids[$taper['id']]);
                    } else {
                        // Taper is new
                        $taper_model = new OphDrPrescription_ItemTaper();
                        $taper_model->item_id = $item_model->id;
                    }
                    $taper_model->dose = $taper['dose'];
                    $taper_model->frequency_id = $taper['frequency_id'];
                    $taper_model->duration_id = $taper['duration_id'];
                    $taper_model->save();
                }
            }
            // Delete remaining (removed) ids
            OphDrPrescription_ItemTaper::model()->deleteByPk(array_values($existing_taper_ids));
            OphDrPrescription_Item::model()->deleteByPk(array_values($existing_item_ids));
        }
    }