examples: Use substrate as polkadot.scale and print codegen

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

codegen/src/api/mod.rs

@@ -155,9 +155,14 @@ fn generate_runtime_call_api(
 ) -> TokenStream2 {
     let mut result = quote!();
 
+    println!("inside runtime: {:?}", runtime);
+
     for trait_ in runtime {
         for method in &trait_.methods {
-            let fn_name = format!("{}{}", trait_.name, method.name);
+            let trait_name = trait_.name.clone();
+            let method_name = method.name.clone();
+
+            let fn_name = format_ident!("{}_{}", trait_.name, method.name);
 
             let mut params = Vec::new();
             for input in &method.inputs {
@@ -172,7 +177,7 @@ fn generate_runtime_call_api(
             let output = type_gen.resolve_type_path(output.id());
 
             let fn_ = quote!(
-                pub fn #fn_name( &self, #( #params, )* ) -> #output {
+                pub fn #fn_name( #( #params, )* ) -> #output {
                     // call into RPC.
                 }
             );

examples/examples/runtime_calls.rs

@@ -0,0 +1,37 @@
+// Copyright 2019-2022 Parity Technologies (UK) Ltd.
+// This file is dual-licensed as Apache-2.0 or GPL-3.0.
+// see LICENSE for license details.
+
+//! To run this example, a local polkadot node should be running. Example verified against polkadot v0.9.28-9ffe6e9e3da.
+//!
+//! E.g.
+//! ```bash
+//! curl "https://github.com/paritytech/polkadot/releases/download/v0.9.28/polkadot" --output /usr/local/bin/polkadot --location
+//! polkadot --dev --tmp
+//! ```
+
+use sp_keyring::AccountKeyring;
+use subxt::{
+    config::{
+        polkadot::{
+            Era,
+            PlainTip,
+            PolkadotExtrinsicParamsBuilder as Params,
+        },
+        PolkadotConfig,
+    },
+    tx::PairSigner,
+    OnlineClient,
+};
+
+#[subxt::subxt(runtime_metadata_path = "../artifacts/polkadot_metadata.scale")]
+pub mod polkadot {}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    tracing_subscriber::fmt::init();
+
+    polkadot::runtime_api::Metadata_metadata();
+
+    Ok(())
+}