Crate pallet_example_offchain_worker[−][src]
Expand description
Offchain Worker Example Pallet
The Offchain Worker Example: A simple pallet demonstrating concepts, APIs and structures common to most offchain workers.
Run cargo doc --package pallet-example-offchain-worker --open
to view this module’s
documentation.
Overview
In this example we are going to build a very simplistic, naive and definitely NOT
production-ready oracle for BTC/USD price.
Offchain Worker (OCW) will be triggered after every block, fetch the current price
and prepare either signed or unsigned transaction to feed the result back on chain.
The on-chain logic will simply aggregate the results and store last 64
values to compute
the average price.
Additional logic in OCW is put in place to prevent spamming the network with both signed
and unsigned transactions, and custom UnsignedValidator
makes sure that there is only
one unsigned transaction floating in the network.
Re-exports
pub use pallet::*;
Modules
Based on the above KeyTypeId
we need to generate a pallet-specific crypto type wrappers.
We can use from supported crypto kinds (sr25519
, ed25519
and ecdsa
) and augment
the types with this pallet-specific identifier.
Structs
Payload used by this example crate to hold price data required to submit a transaction.
Constants
Defines application identifier for crypto keys of this module.