Decoding extrinsic hex into readable form in Rust

Question

I am running the substrate-dev node. Made a transaction using Polkadot-explorer. After fetching the block using subxt I am getting extrinsic hex as:

8400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d016a0d5d23b65049765a0141666edf0108dc326ced62c96a3092a74471c3bd00382aa84dfd9b12ce199560a26ac6126e1f5f50a59bd50c798f408979843153908c66071000000008081234

I want to convert this hex into a readable form in Rust.

Answer 1

You need to confirm the Type first.

Then:

use parity_scale_codec::Decode;

#[derive(Debug, Decode)]
struct MockExtrinsicType { .. }

let extrinsic = MockExtrinsicType::decode(&mut &*array_bytes::hex2bytes_unchecked("8400d43593c715fdd31c61141abd04a99fd6822c8558854ccde39a5684e7a56da27d016a0d5d23b65049765a0141666edf0108dc326ced62c96a3092a74471c3bd00382aa84dfd9b12ce199560a26ac6126e1f5f50a59bd50c798f408979843153908c66071000000008081234"));
println!("{:?}", extrinsic);

Usually, the block type is https://github.com/paritytech/substrate/blob/f2bc08a3071a91b71fec63cf2b22c707411cec0e/primitives/runtime/src/generic/block.rs#L92.

And the extrinsic type is https://github.com/paritytech/substrate/blob/f2bc08a3071a91b71fec63cf2b22c707411cec0e/primitives/runtime/src/lib.rs#L868.

Finally, you need to decode the OpaqueExtrinsic into this https://github.com/paritytech/substrate/blob/f2bc08a3071a91b71fec63cf2b22c707411cec0e/primitives/runtime/src/generic/unchecked_extrinsic.rs#L44.