How to pass foreign_accounts to inner app call in PyTeal

AlgoSDK
1

Hello! In pyteal, is it possibile to pass all foreign accounts to an inner tx call?

Executing:

TxnField.accounts: Gtxn[1].accounts

complains with the following

pyteal.TealInputError: inner transaction set array field TxnField.accounts with non-array value
2

You can pass it as a python list like TxnField.accounts: [Gtxn[1].accounts[0], Gtxn[1].accounts[1],...]

And if you call it multiple times it’ll append to the list

Ben

3

What if the outer app call can have a different number of foreign accounts?
That static implementation you proposed would not work unfortunately.

4

Sure, you can iterate over the length of the outer array and sequential calls to InnerTxnBuilder.SetField(TxnField.accounts, Gtxn[1].accounts[scratchVar.load()]) should append the acct to the list

Ben

5

Ah nice! so subsequent calls to SetField are going to push values on accounts array.
https://pyteal.readthedocs.io/en/stable/api.html?highlight=setfield#pyteal.InnerTxnBuilder.SetField
Many thanks!