Could you please give some examples for ws-client?

[hexinlee]

Hi, this Jsonrpc crate is awesome!! I want to use the Websocket module as client.
Could you please give some examples of "ws client connect", "ws client start_send" and "ws client poll" for core-client/transports/transports/ws.rs file?
Thank you in advance.

[tomusdrw]

Hey @hexinlee!

The idea is that you don't use the transport directly, but rather use the client code generated from a trait via jsonrpc_derive and just pass it the ws transport.

You can find an example here (it's using http, but swapping to ws should be as easy as changing the imports):
https://github.com/paritytech/substrate/blob/e8739300ae3f7f2e7b72f64668573275f2806ea5/node/rpc-client/src/main.rs#L42

And the client code comes from here:
https://github.com/paritytech/substrate/blob/e8739300ae3f7f2e7b72f64668573275f2806ea5/core/rpc/src/author/mod.rs#L52

[dvdplm]

@tomusdrw your comment here would perhaps be a good addition to the Readme?

[hexinlee]

@tomusdrw thank you so much.
Just one question, the WS client can send multiple requests just in one connection, correct?
e.g.
used as: open one connection -> send 1st request -> send 2nd request -> ...... -> close the connection
not used as: open the 1st connection -> send 1st request -> close the 1st connection -> open the 2nd connection -> send 2nd request -> close the 2nd connection ......

[tomusdrw]

@dvdplm Yeah, makes sense. Let me prep a PR later today.
@hexinlee indeed, the connection is re-used.

[hexinlee]

@tomusdrw Thank you so much, another question, I noticed this WS client can request RPC module. Can this WS client access "SRML" module too? Since many storage information is from SRML, could you please also give a simple example for the SRML module access?

[tomusdrw]

@hexinlee Sure you can import a srml module into the client and use the structs that are defined there - note however that some of them might miss Serialize/Deserialize implementations, so you won't be able to directly decode them from the RPC response. An issue in substrate about that: paritytech/substrate#2774