Using resource model class to save back-end configuration

Question

So I have this custom form in the back-end from which I want to save/load values from my custom table in the database.

I have set that form to use a my custom model - this is from the system.xml file in the module:

<backend_model>myproductimporter/system_config_backend_customoptions</backend_model>

This is the class so far:

class MODULE_MyProductImporter_Model_System_Config_Backend_Customoptions extends Mage_Adminhtml_Model_System_Config_Backend_Serialized
{
    /**
     * Constructs an array of custom options data mapped to and organized by their template ID.
     * Save actual data in custom_options_import_templeates table.
     *
     * (non-PHPdoc)
     * @see Mage_Core_Model_Abstract::_beforeSave()
     */
    protected function _beforeSave()
    {
        $value = $this->getValue();
        if (is_array($value)) {
            unset($value['__empty']);
        }

        /* my custom functionality */

        $this->setValue($value);
        parent::_beforeSave();
    }

    protected function _afterLoad() {
        return parent::_afterLoad();
    }
}

So the functionality in these 2 functions is the same as in the parent class. Only the /* my custom functionality /* does some mapping stuff over the data. This manipulated data I want to save in my own way in my own table in the DB.

I have created a Resource model class:

class MODULE_MyProductImporter_Model_Resource_Import_Importer extends Mage_Core_Model_Resource_Db_Abstract {

    protected function construct() {
        $this->_init('myproductimporter/import_importer', 'id');
    }

    public function saveCustomOptions(array $valuesToSave) {
         /* process the data given from the function from Customoptions.php
            and save it in my custom table in the DB */
    }
}

And I have configured the resource class:

<global>
        <models>
            <myproductimporter>
                <class>MODULE_MyProductImporter_Model</class>
                <resourceModel>myproductimporter_resource</resourceModel>
            </myproductimporter>
            <myproductimporter_resource>
                <class>MODULE_MyhProductImporter_Model_Resource_Import_Importer</class>
                <entities>
                    <myproductimporter>
                        <table>custom_options_import_templates</table>
                    </myproductimporter>
                </entities>
            </myproductimporter_resource>
        </models>

What I don't understand is the process flow. Where should I call the saveCustomOptions function? It seems to me that it should be in the _beforeSave but that also doesn't make sense, since this function should finish its job before the save is done. I get until the end of _beforeSave(), but then I am lost in what should I do...

Also, how is the manipulated-and-ready-to-save data (in saveCustomOptions()) processed and saved?

The table where I want to save the data is called custom_options_import_templates

Answer 1

So maybe this does not answer your question here is a small insight into how magento deals with this sort of thing:

1. Mage_Catalog_Model_Resource_Product::_afterSave - saves the links for product to website and category,
2. Mage_Catalog_Model_Resource_Product_Option::_afterSave - saves price and and translation information for product options,
3. Mage_Catalog_Model_Resource_Category::_beforeSave - updates path and children count,
4. Mage_Catalog_Model_Resource_Category::_afterSave - saves product links,
5. Mage_Cms_Model_Resource_Page::_beforeSave - validates a few attributes and sets the created date for new pages,
6. Mage_Cms_Model_Resource_Page::_afterSave - assign pages to stores and invalidate the cache,
7. Mage_Customer_Model_Resource_Customer::_beforeSave - validate some attributes,
8. Mage_Customer_Model_Resource_Customer::_afterSave - trigger save of address,

So from these few items I would say, with a massive generalisation, that Magento tends to use _before save for validation and setting up some default values and used _after to saving information into linked tables.

I hope this helps you make your choice.