Read spec chain in a custom rpc method

Question

I know that some RPC query exist to get informations like : system_properties system_chain system_chainType

But I would like to have all of them in a same custom call. How I can access to those informations ?

Thank you.

Answer 1

All of those RPCs can be found here: https://github.com/paritytech/substrate/blob/master/client/rpc/src/system/mod.rs

impl<B: traits::Block> SystemApi<B::Hash, <B::Header as HeaderT>::Number> for System<B> {

    // -- snip --

    fn system_properties(&self) -> Result<sc_chain_spec::Properties> {
        Ok(self.info.properties.clone())
    }

    // -- snip --

    fn system_sync_state(&self) -> Receiver<SyncState<<B::Header as HeaderT>::Number>> {
        let (tx, rx) = oneshot::channel();
        let _ = self.send_back.unbounded_send(Request::SyncState(tx));
        Receiver(rx)
    }

    // -- snip --
}

These are then implemented in the node's RPC configuration:

https://github.com/paritytech/substrate/blob/master/bin/node/rpc/src/lib.rs

io.extend_with(SystemApi::to_delegate(FullSystem::new(client.clone(), pool, deny_unsafe)));