Trait Payload

pub trait Payload {
    type ReturnType: DecodeWithMetadata;

    // Required methods
    fn trait_name(&self) -> &str;
    fn method_name(&self) -> &str;
    fn encode_args_to(
        &self,
        metadata: &Metadata,
        out: &mut Vec<u8>,
    ) -> Result<(), Error>;

    // Provided methods
    fn encode_args(&self, metadata: &Metadata) -> Result<Vec<u8>, Error> { ... }
    fn validation_hash(&self) -> Option<[u8; 32]> { ... }
}

This represents a runtime API payload that can call into the runtime of node.

Components

• associated return type

Resulting bytes of the call are interpreted into this type.

• runtime function name

The function name of the runtime API call. This is obtained by concatenating the runtime trait name with the trait’s method.

For example, the substrate runtime trait Metadata contains the metadata_at_version function. The corresponding runtime function is Metadata_metadata_at_version.

• encoded arguments

Each argument of the runtime function must be scale-encoded.

Required Associated Types

type ReturnType: DecodeWithMetadata

The return type of the function call.

Required Methods

fn trait_name(&self) -> &str

The runtime API trait name.

fn method_name(&self) -> &str

The runtime API method name.

fn encode_args_to( &self, metadata: &Metadata, out: &mut Vec<u8>, ) -> Result<(), Error>

Scale encode the arguments data.

Provided Methods

fn encode_args(&self, metadata: &Metadata) -> Result<Vec<u8>, Error>

Encode arguments data and return the output. This is a convenience wrapper around Payload::encode_args_to.

fn validation_hash(&self) -> Option<[u8; 32]>

Returns the statically generated validation hash.

Implementors

impl<ArgsData: EncodeAsFields, ReturnTy: DecodeWithMetadata> Payload for DefaultPayload<ArgsData, ReturnTy>

type ReturnType = ReturnTy