FT4 Library/lib.ft4.external.crosschain/validate_apply_transfer

validate_apply_transfer

function validate_apply_transfer(init_transfer_tx: gtx_transaction, init_tx_op_index: integer, previous_hop_tx: gtx_transaction, op_index: integer, hop_index: integer): ((tx_rid: byte_array, args: immutable_mirror_struct<init_transfer>, sender_account_id: byte_array), byte_array)(source)

Validates that the parameters are correct for an apply_transfer operation. Also used in other operations that require the same validation to occur (e.g. cancel_transfer) It does not verify whether the transfer expired.

Among other things, this function validates that:

  • Transfer was not already applied on this chain

  • Transfer was not already canceled on this chain

  • Transfer was not already unapplied on this chain

  • That the init_transfer details are correct

  • The iccf_proof that states that this transfer was applied on the previous hop

Throws "INVALID TRANSACTION" if the transfer has already been applied, canceled or unapplied on this chain.

Throws "INPUT ERROR" if the input is malformed. Common scenarios include:

  • arguments found in init_transfer_tx and previous_hop_tx do not match

  • hop_index is out of bounds

  • previous_hop_tx has not been sent to the chain that comes before this one on the transfer hops

Throws "WRONG BLOCKCHAIN" if the chain at hop_index on the init transaction is not this chain

Throws if the op_index does not point to apply_transfer

Throws if the init_tx_op_index does not point to init_transfer on its init_transfer_tx

Throws if the operation preceding init_transfer is not an auth operation

Throws if the transaction is missing the iccf_proof operation, which demonstrates that the block containing the previous_hop_tx has been anchored from the previous chain.

Parameters

init_transfer_tx

the init transaction, which contains init_transfer, as it was submitted to the starting chain

init_tx_op_index

the index of the init_transfer operation in init_transfer_tx

previous_hop_tx

the transaction that applied the transfer in the chain that comes before this one. Same as init_transfer_tx if this is the first chain where the transfer is applied.

op_index

the index of the apply_transfer operation in previous_hop_tx

hop_index

which index in the hops array provided in the original transaction this chain represents.

See also

core.auth.is_auth_op

for information on auth operations