Expand description
A kind::Id is strongly typed to avoid misuse of Rust APIs, especially
when functions ask for several ids of different types.
The kind::Id also prevents the misuse of any string based API, such
as Rest or GraphQL, by prefixing the internally used ids with a class
prefix.
use kind::*;
// The structs we want to define Id types for are just annotated. The
// Identifiable trait is derived.
#[derive(Debug, Identifiable)]
#[kind(class="Cust")]
pub struct Customer {
// many fields
}
#[derive(Debug, Identifiable)]
#[kind(class="Cont")]
pub struct Contract {
// many fields
}
// Let's start from an id in the database (we use the string representantion
// but kind natively decodes from postgres' Uuid into Id)
let customer_db_id = "371c35ec-34d9-4315-ab31-7ea8889a419a";
// Now, use it to get our Rust instance of Id:
let customer_id: Id<Customer> = Id::from_db_id(customer_db_id).unwrap();
// If we communicate (via serde, Display, or directly), we
// use the public id
let customer_public_id = customer_id.public_id();
assert_eq!(&customer_public_id, "Cust_371c35ec-34d9-4315-ab31-7ea8889a419a");
// When reading an id withtout prefix, from the db, there was
// no type check. It's (almost) OK because we carefully wrote our
// queries. But we need a type check when we read from a public id.
// Let's try to read our public id as a contract id:
let contract_id: Result<Id<Contract>, IdError> = customer_public_id.parse();
assert!(contract_id.is_err());
// And let's check it's OK as a customer id:
let customer_id: Result<Id<Customer>, IdError> = Id::from_public_id(&customer_public_id);
assert!(customer_id.is_ok());
assert_eq!(customer_id.unwrap().db_id(), "371c35ec-34d9-4315-ab31-7ea8889a419a");
// The public id is parsed and checked in a case insensitive way
assert_eq!(customer_id, "cust_371c35ec-34d9-4315-ab31-7ea8889a419a".parse());
assert_eq!(customer_id, "CUST_371C35EC-34D9-4315-AB31-7EA8889A419A".parse());
Macros§
- Create an enumeration whose variants are identifiers of several types.
Structs§
- UUID with costless type constraints
- A category of identifiable objects
- Short for “Identified”, wraps a struct and its identifier.
Enums§
- An error which can be returned by the kind library
Traits§
- An identifiable is an object which can be refered to with an id (the id may be part, or not, of the object).