Macro frame_support_procedural::construct_runtime

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

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

The parameters here are specific types for Block, NodeBlock, and UncheckedExtrinsic and the modules 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 = runtime::Block,
        UncheckedExtrinsic = UncheckedExtrinsic
    {
        System: system::{Module, Call, Event<T>, Config<T>} = 0,
        Test: test::{Module, Call} = 1,
        Test2: test_with_long_module::{Module, Event<T>},

        // Module with instances
        Test3_Instance1: test3::<Instance1>::{Module, Call, Storage, Event<T, I>, Config<T, I>, Origin<T, I>},
        Test3_DefaultInstance: test3::{Module, 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 module. The identifiers between the braces are the module 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:

• Module
• Call
• Storage
• Event or Event<T> (if the event is generic)
• Origin or Origin<T> (if the origin is generic)
• Config or Config<T> (if the config is generic)
• Inherent - If the module provides/can check inherents.
• ValidateUnsigned - If the module validates unsigned extrinsics.

= $n is an optional part allowing to define at which index the module 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):

module1 .. = 2,
module2 .., // Here module2 is given index 3
module3 .. = 0,
module4 .., // Here module4 is given index 1

Note

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