Recommendation Service simply calls the Catalog Service and returns a set of product which is not included in the user's cart. For this filtration also we make use of query expressions.
remote function ListRecommendations(stubs:ListRecommendationsRequest request)
returns stubs:ListRecommendationsResponse|error {
stubs:ListProductsResponse|grpc:Error listProducts = self.catalogClient->ListProducts({});
if listProducts is grpc:Error {
return error grpc:InternalError("Failed to get list of products from catalog service", listProducts);
}
return {
product_ids: from stubs:Product product in listProducts.products
let string productId = product.id
where request.product_ids.indexOf(productId) is ()
limit 5
select productId
};
}