Macro frame_support::construct_runtime[−][src]

construct_runtime!() { /* proc-macro */ }
Expand description

Construct a runtime, with the given name and the given pallets.

The parameters here are specific types for Block, NodeBlock, and UncheckedExtrinsic and the pallets that are used by the runtime. Block is the block type that is used in the runtime and NodeBlock is the block type that is used in the node. For instance they can differ in the extrinsics type.

Example:

construct_runtime!(
    pub enum Runtime where
        Block = Block,
        NodeBlock = node::Block,
        UncheckedExtrinsic = UncheckedExtrinsic
    {
        System: system::{Pallet, Call, Event<T>, Config<T>} = 0,
        Test: test::{Pallet, Call} = 1,
        Test2: test_with_long_module::{Pallet, Event<T>},

        // Pallets with instances
        Test3_Instance1: test3::<Instance1>::{Pallet, Call, Storage, Event<T, I>, Config<T, I>, Origin<T, I>},
        Test3_DefaultInstance: test3::{Pallet, Call, Storage, Event<T>, Config<T>, Origin<T>} = 4,
    }
)

The identifier System is the name of the pallet and the lower case identifier system is the name of the Rust module/crate for this Substrate pallet. The identifiers between the braces are the pallet parts provided by the pallet. It is important to list these parts here to export them correctly in the metadata or to make the pallet usable in the runtime.

We provide support for the following module parts in a pallet:

  • Pallet - Required for all pallets
  • Call - If the pallet has callable functions
  • Storage - If the pallet uses storage
  • Event or Event<T> (if the event is generic) - If the pallet emits events
  • Origin or Origin<T> (if the origin is generic) - If the pallet has instanciable origins
  • Config or Config<T> (if the config is generic) - If the pallet builds the genesis storage with GenesisConfig
  • Inherent - If the pallet provides/can check inherents.
  • ValidateUnsigned - If the pallet validates unsigned extrinsics.

= $n is an optional part allowing to define at which index the pallet variants in OriginCaller, Call and Event are encoded, and to define the ModuleToIndex value.

if = $n is not given, then index is resolved same as fieldless enum in Rust (i.e. incrementedly from previous index):

pallet1 .. = 2,
pallet2 .., // Here pallet2 is given index 3
pallet3 .. = 0,
pallet4 .., // Here pallet4 is given index 1

Note

The population of the genesis storage depends on the order of pallets. So, if one of your pallets depends on another pallet, the pallet that is depended upon needs to come before the pallet depending on it.

Type definitions

  • The macro generates a type alias for each pallet to their Module (or Pallet). E.g. type System = frame_system::Pallet<Runtime>