Update Offchain worker docs: could not find `SyncCryptoStore` in `sp_keystore`

[doutv]

This should be Code Bug Report, not requesting for new content. I make a mistake in issue label.

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Content request

Problem

When I follows the offchain worder guide here https://docs.substrate.io/tutorials/build-application-logic/add-offchain-workers/#unsigned-transactions

Using a development account If you are running a node in development mode—with --dev command-line option—you can manually generate and insert the account key for a development account by modifying the node/src/service.rs file as follows:

pub fn new_partial(config: &Configuration) -> Result <SomeStruct, SomeError> {

//...

  if config.offchain_worker.enabled {
  // Initialize seed for signing transaction using offchain workers. This is a convenience
  // so learners can see the transactions submitted simply running the node.
  // Typically these keys should be inserted with RPC calls to `author_insertKey`.
   	sp_keystore::SyncCryptoStore::sr25519_generate_new(
   		&*keystore,
   		node_template_runtime::pallet_your_ocw_pallet::KEY_TYPE,
   		Some("//Alice"),
   	).expect("Creating key with account Alice should succeed.");
   	}
}

This example manually adds the key for the Alice account to the keystore identified by the KEY_TYPE defined in your pallet. For a working example, see this sample service.rs file.

I meet the following error

error[E0433]: failed to resolve: could not find `SyncCryptoStore` in `sp_keystore`
   --> node/src/service.rs:141:16
    |
141 |         sp_keystore::SyncCryptoStore::sr25519_generate_new(
    |                      ^^^^^^^^^^^^^^^ could not find `SyncCryptoStore` in `sp_keystore`

Solution

With Polkadot-v1.0.0 and sp-keystore version = "0.27.0": there is no SyncCryptoStore in sp_keystore. Use sp_keystore::Keystore::sr25519_generate_new

pub fn new_partial(config: &Configuration) -> Result <SomeStruct, SomeError> {

//...

  if config.offchain_worker.enabled {
  // Initialize seed for signing transaction using offchain workers. This is a convenience
  // so learners can see the transactions submitted simply running the node.
  // Typically these keys should be inserted with RPC calls to `author_insertKey`.
   	sp_keystore::Keystore::sr25519_generate_new(
   		&*keystore,
   		node_template_runtime::pallet_your_ocw_pallet::KEY_TYPE,
   		Some("//Alice"),
   	).expect("Creating key with account Alice should succeed.");
   	}
}

Are you willing to help with this request?

Yes!