Magento – Get product custom option value

Even tho custom option renderers can be added via layout update by calling addOptionRenderer on product.info.options block, using custom types will never work without rewriting getGroupByType method inside Mage_Catalog_Model_Product_Option class.

You can trick Magento to show your custom type on product view page by doing something like this in local.xml

<catalog_product_view>
        <reference name="product.info.options.wrapper">
            <block type="foo_bar/options" name="product.info.options" as="product_options" template="catalog/product/view/options.phtml">
                <action method="addOptionRenderer"><type>text</type><block>catalog/product_view_options_type_text</block><template>catalog/product/view/options/type/text.phtml</template></action>
                <action method="addOptionRenderer"><type>file</type><block>catalog/product_view_options_type_file</block><template>catalog/product/view/options/type/file.phtml</template></action>
                <action method="addOptionRenderer"><type>select</type><block>catalog/product_view_options_type_select</block><template>catalog/product/view/options/type/select.phtml</template></action>
                <action method="addOptionRenderer"><type>date</type><block>catalog/product_view_options_type_date</block><template>catalog/product/view/options/type/date.phtml</template></action>
                <action method="addOptionRenderer"><type>test</type><block>foo_bar/options_test</block><template>foo_bar/options/test.phtml</template></action>
            </block>
        </reference>
    </catalog_product_view>

Block class:

class Foo_Bar_Block_Options extends Mage_Catalog_Block_Product_View_Options
{
    public function getOptionHtml(Mage_Catalog_Model_Product_Option $option)
    {
        if ($option->getType() == 'test') {
            $renderer = $this->getOptionRender(
                $option->getType()
            );
        } else {
            $renderer = $this->getOptionRender(
                $this->getGroupOfOption($option->getType())
            );
        }

        if (is_null($renderer['renderer'])) {
            $renderer['renderer'] = $this->getLayout()->createBlock($renderer['block'])
                ->setTemplate($renderer['template']);
        }

        return $renderer['renderer']
            ->setProduct($this->getProduct())
            ->setOption($option)
            ->toHtml();
    }
}

And this will work until you try to add to cart because that is when getGroupByType is called again and we get a nice error message. :)

go to app/design/frontend/theme_package/theme/layout/catalog.xml

in below action

<catalog_product_view>
</catalog_product_view>

add this code

<reference name="head">
            <action method="addJs"><script>varien/product.js</script></action>
            <action method="addJs"><script>varien/product_options.js</script></action>
            <action method="addJs"><script>varien/configurable.js</script></action>

</reference>