Struct Resolver

pub struct Resolver<DOC = CoreDocument, CMD = SendSyncCommand<DOC>>
where
    CMD: for<'r> Command<'r, Result<DOC, Error>>,
{ /* private fields */ }

Convenience type for resolving DID documents from different DID methods.

Configuration

The resolver will only be able to resolve DID documents for methods it has been configured for. This is done by attaching method specific handlers with Self::attach_handler.

Implementations

impl<M, DOC> Resolver<DOC, M>

where M: for<'r> Command<'r, Result<DOC, Error>>,

pub fn new() -> Resolver<DOC, M>

Constructs a new Resolver.

Example

Construct a Resolver that resolves DID documents of type CoreDocument.

let mut resolver = Resolver::<CoreDocument>::new();
// Now attach some handlers whose output can be converted to a `CoreDocument`.

pub async fn resolve<D>(&self, did: &D) -> Result<DOC, Error>

where D: DID,

Fetches the DID Document of the given DID.

Errors

Errors if the resolver has not been configured to handle the method corresponding to the given DID or the resolution process itself fails.

Example

async fn configure_and_resolve(
  did: CoreDID,
) -> std::result::Result<CoreDocument, Box<dyn std::error::Error>> {
  let resolver: Resolver = configure_resolver(Resolver::new());
  let resolved_doc: CoreDocument = resolver.resolve(&did).await?;
  Ok(resolved_doc)
}

fn configure_resolver(mut resolver: Resolver) -> Resolver {
  resolver.attach_handler("foo".to_owned(), resolve_foo);
  // Attach handlers for other DID methods we are interested in.
  resolver
}

async fn resolve_foo(did: CoreDID) -> std::result::Result<CoreDocument, std::io::Error> {
  todo!()
}

pub async fn resolve_multiple<D>( &self, dids: &[D], ) -> Result<HashMap<D, DOC>, Error>

where D: DID,

Concurrently fetches the DID Documents of the multiple given DIDs.

Errors

• If the resolver has not been configured to handle the method of any of the given DIDs.
• If the resolution process of any DID fails.

Note

• If dids contains duplicates, these will be resolved only once.

impl<DOC> Resolver<DOC>

where DOC: 'static,

pub fn attach_handler<D, F, Fut, DOCUMENT, E, DIDERR>( &mut self, method: String, handler: F, )

where D: DID<Error = DIDERR> + Send + for<'r> TryFrom<&'r str> + 'static, DOCUMENT: 'static + Into<DOC>, F: Fn(D) -> Fut + 'static + Clone + Send + Sync, Fut: Future<Output = Result<DOCUMENT, E>> + Send, E: Into<Box<dyn Error + Send + Sync>>, DIDERR: Into<Box<dyn Error + Send + Sync>>,

Attach a new handler responsible for resolving DIDs of the given DID method.

The handler is expected to be a closure taking an owned DID and asynchronously returning a DID Document which can be converted to the type this Resolver is parametrized over. The handler is required to be Clone, Send, Sync and 'static hence all captured variables must satisfy these bounds. In this regard the move keyword and (possibly) wrapping values in an Arc may come in handy (see the example below).

NOTE: If there already exists a handler for this method then it will be replaced with the new handler. In the case where one would like to have a “backup handler” for the same DID method, one can achieve this with composition.

Example

   // A client that can resolve DIDs of our invented "foo" method.
   struct Client;

   impl Client {
     // Resolves some of the DIDs we are interested in.
     async fn resolve(&self, _did: &CoreDID) -> std::result::Result<CoreDocument, std::io::Error> {
       todo!()
     }
   }

   // This way we can essentially produce (cheap) clones of our client.
   let client = std::sync::Arc::new(Client {});

   // Get a clone we can move into a handler.
   let client_clone = client.clone();

   // Construct a resolver that resolves documents of type `CoreDocument`.
   let mut resolver = Resolver::<CoreDocument>::new();

   // Now we want to attach a handler that uses the client to resolve DIDs whose method is "foo".
   resolver.attach_handler("foo".to_owned(), move |did: CoreDID| {
     // We want to resolve the did asynchronously, but since we do not know when it will be awaited we
     // let the future take ownership of the client by moving a clone into the asynchronous block.
     let future_client = client_clone.clone();
     async move { future_client.resolve(&did).await }
   });

impl<DOC> Resolver<DOC, SingleThreadedCommand<DOC>>

where DOC: 'static,

pub fn attach_handler<D, F, Fut, DOCUMENT, E, DIDERR>( &mut self, method: String, handler: F, )

where D: DID<Error = DIDERR> + for<'r> TryFrom<&'r str> + 'static, DOCUMENT: 'static + Into<DOC>, F: Fn(D) -> Fut + 'static + Clone, Fut: Future<Output = Result<DOCUMENT, E>>, E: Into<Box<dyn Error + Send + Sync>>, DIDERR: Into<Box<dyn Error + Send + Sync>>,

Attach a new handler responsible for resolving DIDs of the given DID method.

The handler is expected to be a closure taking an owned DID and asynchronously returning a DID Document which can be converted to the type this Resolver is parametrized over. The handler is required to be Clone and 'static hence all captured variables must satisfy these bounds. In this regard the move keyword and (possibly) wrapping values in an std::rc::Rc may come in handy (see the example below).

NOTE: If there already exists a handler for this method then it will be replaced with the new handler. In the case where one would like to have a “backup handler” for the same DID method, one can achieve this with composition.

Example

   // A client that can resolve DIDs of our invented "foo" method.
   struct Client;

   impl Client {
     // Resolves some of the DIDs we are interested in.
     async fn resolve(&self, _did: &CoreDID) -> std::result::Result<CoreDocument, std::io::Error> {
       todo!()
     }
   }

   // This way we can essentially produce (cheap) clones of our client.
   let client = std::rc::Rc::new(Client {});

   // Get a clone we can move into a handler.
   let client_clone = client.clone();

   // Construct a resolver that resolves documents of type `CoreDocument`.
   let mut resolver = SingleThreadedResolver::<CoreDocument>::new();

   // Now we want to attach a handler that uses the client to resolve DIDs whose method is "foo".
   resolver.attach_handler("foo".to_owned(), move |did: CoreDID| {
     // We want to resolve the did asynchronously, but since we do not know when it will be awaited we
     // let the future take ownership of the client by moving a clone into the asynchronous block.
     let future_client = client_clone.clone();
     async move { future_client.resolve(&did).await }
   });

impl<DOC> Resolver<DOC, SingleThreadedCommand<DOC>>

where DOC: From<CoreDocument> + 'static,

pub fn attach_did_jwk_handler(&mut self)

Attaches a handler capable of resolving did:jwk DIDs.

impl<DOC> Resolver<DOC>

where DOC: From<CoreDocument> + 'static,

pub fn attach_did_jwk_handler(&mut self)

Attaches a handler capable of resolving did:jwk DIDs.

impl<DOC> Resolver<DOC>

where DOC: From<IotaDocument> + AsRef<CoreDocument> + 'static,

pub fn attach_iota_handler<CLI>(&mut self, client: CLI)

where CLI: DidResolutionHandler + Send + Sync + 'static,

Convenience method for attaching a new handler responsible for resolving IOTA DIDs.

See also attach_handler.

pub fn attach_multiple_iota_handlers<CLI, I>(&mut self, clients: I)

where CLI: DidResolutionHandler + Send + Sync + 'static, I: IntoIterator<Item = (&'static str, CLI)>,

Convenience method for attaching multiple handlers responsible for resolving IOTA DIDs on multiple networks.

Arguments

• clients - A collection of tuples where each tuple contains the name of the network name and its corresponding client.

Examples

// Assume `client1` and `client2` are instances of identity clients `IdentityClientReadOnly`.
attach_multiple_iota_handlers(vec![("client1", client1), ("client2", client2)]);

See Also

• attach_handler.

Note

• Using attach_iota_handler or attach_handler for the IOTA method would override all previously added clients.
• This function does not validate the provided configuration. Ensure that the provided network name corresponds with the client, possibly by using client.network_name().

Trait Implementations

impl<CMD, DOC> Debug for Resolver<DOC, CMD>

where CMD: for<'r> Command<'r, Result<DOC, Error>>, DOC: AsRef<CoreDocument>,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<CMD, DOC> Default for Resolver<DOC, CMD>

where CMD: for<'r> Command<'r, Result<DOC, Error>>, DOC: AsRef<CoreDocument>,

fn default() -> Resolver<DOC, CMD>

Returns the “default value” for a type.