Environment Information
Transaction Information​
To get the addresses of the signers of a transaction,
use the address
field of each signing AuthAccount
that is passed to the transaction's prepare
phase.
There is currently no API that allows getting other transaction information. Please let us know if your use-case demands it by request this feature in an issue.
Block Information​
To get information about a block, the functions getCurrentBlock
and getBlock
can be used:
-
_10view fun getCurrentBlock(): Block
Returns the current block, i.e. the block which contains the currently executed transaction.
-
_10view fun getBlock(at: UInt64): Block?
Returns the block at the given height. If the block exists within the accessible range defined by
flow.DefaultTransactionExpiry - 10
(590
blocks), it is returned successfully. If the block at the given height does not exist or is outside the default transaction expiration range of590
blocks below the current sealed block, the function returnsnil
.
The Block
type contains the identifier, height, and timestamp:
_35access(all)_35struct Block {_35 /// The ID of the block._35 ///_35 /// It is essentially the hash of the block._35 ///_35 access(all)_35 let id: [UInt8; 32]_35_35 /// The height of the block._35 ///_35 /// If the blockchain is viewed as a tree with the genesis block at the root,_35 // the height of a node is the number of edges between the node and the genesis block_35 ///_35 access(all)_35 let height: UInt64_35_35 /// The view of the block._35 ///_35 /// It is a detail of the consensus algorithm. It is a monotonically increasing integer_35 /// and counts rounds in the consensus algorithm. It is reset to zero at each spork._35 ///_35 access(all)_35 let view: UInt64_35_35 /// The timestamp of the block._35 ///_35 /// Unix timestamp of when the proposer claims it constructed the block._35 ///_35 /// NOTE: It is included by the proposer, there are no guarantees on how much the time stamp can deviate from the true time the block was published._35 /// Consider observing blocks’ status changes off-chain yourself to get a more reliable value._35 ///_35 access(all)_35 let timestamp: UFix64_35}