extrinsics: Decode extrinsics from blocks (#929)

* Update polkadot.scale

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

* extrinsics: Add extrinsics client

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

* extrinsics: Decode extrinsics

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

* subxt: Add extrinsic error

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

* blocks: Expose extrinsics

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

* examples: Fetch and decode block extrinsics

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

* Fix clippy

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

* extrinsics: Fetch pallet and variant index

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

* subxt: Move extrinsics on the subxt::blocks

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

* example: Adjust example

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

* metadata: Collect ExtrinsicMetadata

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

* subxt: Implement StaticExtrinsic for the calls

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

* Adjust examples

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

* codegen: Add root level Call enum

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

* Adjust testing

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

* subxt: Add new decode interface

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

* subxt: Merge ExtrinsicError with BlockError

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

* examples: Find first extrinsic

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

* Move code to extrinsic_types

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

* Add Extrinsic struct

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

* Adjust examples

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

* test: Decode extinsics

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

* extrinsics/test: Add fake metadata for static decoding

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

* extrinsics/test: Decode from insufficient bytes

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

* extrinsics/test: Check unsupported versions

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

* extrinsics/test: Statically decode to root and pallet enums

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

* extrinsics/tests: Remove clones

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

* blocks: Fetch block body inline

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

* blocks: Rename ExtrinsicIds to ExtrinsicPartTypeIds

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

* extrinsics/test: Check decode as_extrinsic

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

* blocks: Remove InsufficientData error

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

* blocks: Return error from extrinsic_metadata

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

* extrinsics: Postpone decoding of call bytes

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

* metadata_type: Rename variables

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

* Adjust calls path for example and tests

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

* examples: Remove traces

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

* book: Add extrinsics documentation

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

* book: Improve extrinsics docs

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

---------

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>
Co-authored-by: James Wilson <james@jsdw.me>

examples/examples/blocks_subscribing.rs

@@ -25,7 +25,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
         // Log each of the extrinsic with it's associated events:
         let body = block.body().await?;
-        for ext in body.extrinsics() {
+        for ext in body.extrinsics().iter() {
+            let ext = ext?;
             let idx = ext.index();
             let events = ext.events().await?;
             let bytes_hex = format!("0x{}", hex::encode(ext.bytes()));