let do_search = function() {
    // console.log("hello");
    for(i = 0; i < app.products.length; i++){
        var this_product = app.products[i];
        if(this_product.name.includes(app.search_string)){
            this_product.isHidden = false;
        }
        else{
            this_product.isHidden = true;
        }
    }
}