How to get product listing with multiple categories selection ?

[jundi]

Dear Master,

I am developing VM module. I want to have module that capable to display product when the user select a multiple category on the module manager. I am trying to do that, but it still stuck at here :

Code Select Expand


$category_id = $this->_params->get('virtuemart', array());

$productModel = VmModel::getModel('Product');

$items = $productModel->getProductListing($Product_group, $max_items, $show_price, true, false,$filter_category, $category_id);


From above code, the value of category_id will be an array. So, it will be an error happen.

Please give me advice to solve it.

Kindest Regards