I'm trying to work with ERC 721 tokens in such a way that my contract freezes and unfreezes them (based on some conditions) but I'm having trouble wrapping function calls to the ERC 721 token contract address while preserving permissioning from msg.sender - any help much appreciated!
contract 721TokenFreezer{
function freezeToken(address _tokenToFreezeAddress, uint256 _tokenToFreezeId) {
// I want to transfer ownership of the 721 token from msg.sender to this smart contract
}
function unfreezeToken(address _tokenToFreezeAddress, uint256 _tokenToFreezeId, address _to){
//I want to send the 721 token to the _to address
}
transfer
call needs to come from my smart contract; freezing it is just incidental to executing the transfer from my smart contract