Explode tags comma delimited

explodeTags.php

<?php

/**
 * Overridden product meta data model.
 * This model is used as the data source when generating the tagging elements
 * on the product page, and when making server-to-server API calls to Nosto.
 */
class My_Nosto_Model_Meta_Product extends Nosto_Tagging_Model_Meta_Product
{

    /**
     * @inheritdoc
     */
    public function loadData (Mage_Catalog_Model_Product $product, Mage_Core_Model_Store $store = null)
    {
        if (is_null($store)) {
            $store = Mage::app()->getStore();
        }
        parent::loadData($product, $store);

        $this->setTag1($this->expodeTags($this->getTag1()));
        $this->setTag2($this->expodeTags($this->getTag2()));
        $this->setTag3($this->expodeTags($this->getTag3()));

        return true;
    }

    /**
     * @param array $tagsArray
     * @return array
     */
    private function expodeTags(array $tagsArray)
    {
        $finalTags = array();
        foreach ($tagsArray as $tag) {
            $property = explode(':', $tag);
            $values = explode(',', $property[1]);
            foreach ($values as $value) {
                $finalTags[] = $property[0].':'.$value;
            }
        }
        return $finalTags;
    }
}