Lesson 17: DAO voteCastBySig

[dRoysch]

Hello there!

I have some doubts reading this forum https://forum.openzeppelin.com/t/what-is-votecastbysig/17069

who call voteCastBySig? I understand this function call returns _callVote, thats means this function will make eventually a change in the state. Then gas is spending, it means this function is intended to be call for the subsidizing project.

But how the project access the params? I mean this function needs besides proposalId:

        uint8 support,
        uint8 v,
        bytes32 r,
        bytes32 s

At the forum they said "A voter needs to create an EIP712 1 signature containing their vote."

I suppose the organization needs to implement EIP712 and somehow they obtain all voters params (support, v, r, s) offchain and then iterate on this voteCastBySig? Or am I misunderstanding the whole thing?

Thank you a lot!