Struct flow_sdk::entities::Event

pub struct Event {
    pub ty: String,
    pub transaction_id: Box<[u8]>,
    pub transaction_index: u32,
    pub event_index: u32,
    pub payload: Box<[u8]>,
}

An event is emitted as the result of a transaction execution.

Events are either user-defined events originating from a Cadence smart contract, or built-in Flow system events.

Fields

ty: String

Fully-qualified unique type identifier for the event

transaction_id: Box<[u8]>

ID of the transaction the event was emitted from

transaction_index: u32

Zero-based index of the transaction within the block

event_index: u32

Zero-based index of the event within the transaction

payload: Box<[u8]>

Event fields encoded as JSON-Cadence values

Implementations

impl Event

pub fn parse_payload_as_value(&self) -> Result<ValueOwned>

Parses the payload of this event as a cadence JSON value.

pub fn parse_payload(&self) -> Result<CompositeOwned>

Parses the payload of this event.

Examples found in repository

examples/events.rs (line 33)

↕

fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
    let mut client = TonicHyperFlowClient::mainnet().await?;
    client.ping().await?;

    let latest_block_height = client.latest_block_header(Seal::Sealed).await?.height;
    let start_height = latest_block_height - 20;

    println!(
        "Searching for accounts created within the last 20 blocks ({}-{})...",
        start_height, latest_block_height
    );

    for events in client
        .events_for_height_range("flow.AccountCreated", start_height, latest_block_height)
        .await?
        .results
        .iter()
    {
        if events.events.is_empty() {
            continue;
        }
        println!(
            "\nBlock #{} ({}):",
            events.block_height,
            hex::encode(&events.block_id)
        );
        for event in events.events.iter() {
            let val = event.parse_payload()?;

            println!("  - {:#?}", val);
        }
    }

    Ok(())
}

examples/transactions.rs (line 65)

↕

fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
    let stdin = stdin();
    let mut stdin = stdin.lock();
    let mut buf = String::new();

    // Let's make a transaction!

    // First, generate a keypair for us to use.
    let secp = Secp256k1::signing_only();

    // `EntropyRng` is a secure random number generator.
    let mut rng = secp256k1::rand::rngs::EntropyRng::new();
    let secret_key = SecretKey::new(&mut rng);
    let public_key = PublicKey::from_secret_key(&secp, &secret_key);

    // Print the public key as a hexadecimal.
    println!("This is your public key:");
    let public_key_bytes = public_key.serialize_uncompressed();
    // There is a leading 0x04 which we don't need to emit
    // https://bitcoin.stackexchange.com/a/3043
    for ch in &public_key_bytes[1..] {
        print!("{:02x}", *ch);
    }
    println!();
    println!("Go to https://flow-faucet.vercel.app/, select secp256k1 and sha3 and create your testnet account.");
    println!("Paste the address you get and press ENTER to continue");

    stdin.read_line(&mut buf)?;

    let addr = buf.trim();

    let address: AddressOwned = addr.parse()?;
    let net = TonicHyperFlowClient::testnet().await?;

    let mut account = Account::<_, _>::new(net, &address.data, secret_key).await?;

    let create_account = CreateAccountTransaction {
        public_keys: &[public_key],
    };

    let create_account_header = create_account.to_header::<_, tiny_keccak::Sha3>(account.signer());
    let res = account
        .send_transaction_header(&create_account_header)
        .await?;

    println!(
        "Just made {} to create another account :p",
        hex::encode(&res.id)
    );

    let response = res.finalize(account.client()).await?;

    match response {
        Some(res) => {
            for ev in res.events.iter() {
                if ev.ty == "flow.AccountCreated" {
                    let payload = ev.parse_payload()?;

                    let addr = payload
                        .fields
                        .into_iter()
                        .find(|field| field.name == "address")
                        .map(|field| field.value)
                        .unwrap();
                    if let ValueOwned::Address(addr) = addr {
                        println!("Created account's address is: {}", addr);
                    }
                }
            }
        }
        None => {
            panic!("The transaction did not get sealed... Perhaps the network is malfunctioning?")
        }
    }

    Ok(())
}

Trait Implementations

impl Debug for Event

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

Formats the value using the given formatter.

impl<'de> Decodable<'de> for Event where
    Self: Default, 

type Wire = LengthDelimitedWire

fn decode<B: Buf>(d: &mut Deserializer<'de, B>) -> Result<Self>

fn merge(&mut self, other: Self)

If this is a message, call merge() on all fields, if this is repeated, extend this with the elements of other. for all other types simply overwrite this with other, which is the default.

fn merge_from<B>(
    &mut self,
    deserializer: &mut Deserializer<'de, B>
) -> Result<(), DecodingError> where
    B: Buf, 

impl<'de> DecodableMessage<'de> for Event

type Tag = u8

How big the tag message gets. This is an unsigned varint.

fn decode_field<B: Buf>(
    &mut self,
    d: &mut Deserializer<'de, B>,
    tag: Self::Tag
) -> Result<()>

Decodes a field with the given tag.

fn decode<B>(
    deserializer: &mut Deserializer<'de, B>
) -> Result<Self, DecodingError> where
    B: Buf,
    Self: Default, 

impl Default for Event

fn default() -> Event

Returns the “default value” for a type.