Reference

Extractor module

// NOTE: address and topics can be used to filter events at the Ethereum node
//  level.
function init(start = 0, end, address, topics, stepSize = 1)

start Start block as a natural number in decimal-base (default: 0).
end End block as a natural number in decimal-base.
address “0x”- prefixed Ethereum address of where an event log originates from.
topics Array containing up to three 32 byte long “0x”-prefixed topic hashes related to the event or an array of arrays containing such values.
stepSize The distance between fromBlock and toBlock (default: 1) in decimal-base.

Transformer module

function onLine(line, topics = [], address)

line Is an argument defined by @attestate/crawler internally. It is a line within the strategy’s input.path file.
address “0x”- prefixed Ethereum address of where an event log originates from.
topics Array containing up to three 32 byte long “0x”-prefixed topic hashes related to the event.

Loader module

function* order(line) returns ({key, value})

line Is an argument defined by @attestate/crawler internally. It is a line within the strategy’s input.path file.

order is a JavaScript generator function. As the key it concatenats blockNumber and transactionIndex to generate an identifier which defines a total order among transactionHash``es. ``value is the transactionHash.

function* direct(line) returns ({key, value})

line Is an argument defined by @attestate/crawler internally. It is a line within the strategy’s input.path file.

direct is a JavaScript generator function. As the key it defines the transactionHash to generate an identifier which lets us directly access the log through value.