IERC1400TokensSender in ERC1820 Registry

In ERC1400Raw.sol there is an instantiation of IERC1400TokensSender by calling ERC1820Client.interfaceAddr().

address senderImplementation;
senderImplementation = interfaceAddr(from, ERC1400_TOKENS_SENDER);
if (senderImplementation != address(0)) {
    IERC1400TokensSender(senderImplementation).tokensToTransfer(msg.sig, partition, operator, from, to, value, data, operatorData);
}

In order to make this work, I suppose there should be a registration of ERC1400_TOKENS_SENDER to ERC1820 somewhere, by calling ERC1820Client.setInterfaceImplementation(ERC1400_TOKENS_SENDER, {address of contract}), but I could not find similar code in the repo.

Is there anything wrong with my understanding? Thanks.

[jasonclinx]

@victorwiebe got you! Yes ‘setHookContract()’ is the key part to make it work.

[onigiri-x]

Just to clarify and make sure we are on the same page, you dont need to run the unit tests to get the project working. That is what migrations are for if you want to deploy things automatically set up. But the unit tests show us what we can do with the token+javascript. You can call sethookcontract on your choice of provider, and environment whether it be a node.js project with ethersjs/web3, or remix, etc. You just need to call the function

The tl;dr here is method:

setHookContract(address validatorAddress, string interfaceLabel)