Struct subxt::events::Events

pub struct Events<T: Config> { /* private fields */ }

A collection of events obtained from a block, bundled with the necessary information needed to decode and iterate over them.

Implementations

impl<T: Config> Events<T>

pub async fn new_from_client<Client>(
    metadata: Metadata,
    block_hash: T::Hash,
    client: Client
) -> Result<Self, Error>where
    Client: OnlineClientT<T>,

Obtain the events from a block hash given custom metadata and a client.

This method gives users the ability to inspect the events of older blocks, where the metadata changed. For those cases, the user is responsible for providing a valid metadata.

Example

 use subxt::{ OnlineClient, PolkadotConfig, events::Events };

 let client = OnlineClient::<PolkadotConfig>::new().await.unwrap();

 // Get the hash of an older block.
 let block_hash = client
    .rpc()
    .block_hash(Some(1u32.into()))
    .await?
    .expect("didn't pass a block number; qed");
 // Fetch the metadata of the given block.
 let metadata = client.rpc().metadata(Some(block_hash)).await?;
 // Fetch the events from the client.
 let events = Events::new_from_client(metadata, block_hash, client);

Note

Prefer to use crate::events::EventsClient::at to obtain the events.

pub fn len(&self) -> u32

The number of events.

pub fn is_empty(&self) -> bool

Are there no events in this block?

pub fn block_hash(&self) -> T::Hash

Return the block hash that these events are from.

pub fn iter(
    &self
) -> impl Iterator<Item = Result<EventDetails, Error>> + Send + Sync + 'static

Iterate over all of the events, using metadata to dynamically decode them as we go, and returning the raw bytes and other associated details. If an error occurs, all subsequent iterations return None.

pub fn find<Ev: StaticEvent>(
    &self
) -> impl Iterator<Item = Result<Ev, Error>> + '_

Iterate through the events using metadata to dynamically decode and skip them, and return only those which should decode to the provided Ev type. If an error occurs, all subsequent iterations return None.

pub fn find_first<Ev: StaticEvent>(&self) -> Result<Option<Ev>, Error>

Iterate through the events using metadata to dynamically decode and skip them, and return the first event found which decodes to the provided Ev type.

pub fn has<Ev: StaticEvent>(&self) -> Result<bool, Error>

Find an event that decodes to the type provided. Returns true if it was found.

Trait Implementations

impl<T: Config> Clone for Events<T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Config> Debug for Events<T>

fn fmt(&self, __f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.